Fiesers' Reagents for Organic Synthesis (Volume 21)

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e{ 6f7,,L

Fiesers'

kagT 068x

for Reagents OrganicSynthesis

v.Jl

VOLUME TWENTY ONE

Tse-LokHo National Chiao Tung University Republicof China

@WTI.EYINTERSCIENCE A JOHNWILEY & SONS.INC..PUBLICATION

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retrievalsystem'or transmittedin any form No part of this publicationmay be reproduced.storedin a orbyanymeans,electronic,mechanical,photocopying'recording'scanning'orotherwise'exceptas Act, without either the prior perrnitted under Sections 107 or 108 of the 1976 United states copyright writtenpermissionofthePublisher,orauthorizationthoughpaymentoftheappropri?teper-copyfee totheCopyrightClearancecenter'Inc.,222RosewoodDrive,Danvers,MA0l923,978-750-8400' fax978-750-44.l0,oronthewebatwww.copyright.com.RequeststothePublisherforpermission Wiley & Sons' Inc'' I I I River Street' should be addressedto the PermissionsDepartment' John email: permreq@wiley'com' (201) 748-6008' Hoboken,NJ 07030,(201) 748-601l, fax and author have used their best efforts Limit of Liability/Disclarmer of Wananty: while the publisher with respectto the accuracyor w.uranties or no representations make they thisbook, in preparing completenessofthecontentsofthisbookandSpecificallydisclaimanyimpliedwarrantiesof may be createdor extendedby sales merchantability of fitnessfor a particular purpose' No warranty containedherein may not be strategies and advice representative;or written salesmaterials.The suitableforyoursituation.Youshouldconsultwithaprofessionalwhereappropriate.Neitherthe publishernorauthorshallbeliableforanylossofprofitoranyothercommercialdamages,including tut not limited to special, incidental' consequential'or other damages' pleasecontact our Customer Care For general information on our other products and services at 31'I-572-3993 orfax317-5'72-4002' u.s. the Dep"artmentwithin the u.S. ^18'77-762-2974,outside

Library of Congrcss Cataloging in Publication Data: ISBN 0-471-21393-4 I S S N0 2 7 1 - 6 1 6 X Printedin the United Statesof America' 10987654321

I

:,-€

{:ra:

ar

l 98%

rUeda,M., Miyaura,N. "IoC65' 4450(2000). 2Hayashi, M' 'IACS121,11591(1999)' Y.,Ogasawara, T.,Takaya, T., Senda, lHayashi,T., Senda,T., Ogasawara, M. JACSl2l' 10116(1999)'

N-Acetylcysteine' The Amidines.t The title compoundcatalyzesthe addition of ammonia to nitriles. groups' functional many with compatible are reactionconditions rLanee.U.E.W.,Sch?ifer, E', Mack'H'TL40'1067 (1999)' B., Baucke,D., Buschmann,

1,3,5-triazir 2-Acyloxy-4,6-dimethoxyEsters.t Preparedfrom 2-chloroto ak undergotransacylation compounds

J.8.,Kaminski,2.J.,Gora.J 5 19 Kaminska,

N-Acyl-N-(pentafl uorophenyl )meihra N-Acylation.t Amides are formed examples,62-99Vo).

8., Nakao.J..\luralrr Kondo,K., Sekimoto, L-Acylbenzotriazoles. pDicarbonyl compound.s,t c-Acylation reported(18 examPles,36-92Vo). rKatritzky, A. JOC 65' 3679(2000)' A.R.,Pastor,

of ketones with these reagents are

Acylzirconocene chlorides. Acyl anion equivalents.t Additrcn mode.This Pd-catalyzedreactionprorrd

Acylzirconocene chlorides

N-Acyl-5,S-dimethyloxazolidin-2-ones. As latent aaehydes.t Wadsworth condensation.

Dibal-H reduction affords aldehydes for the Emmons-

I Bach,J.,Bull, S.D.,Davies, S.G.,Nicholson, R.L.,Sanganee, H.J.,Smith,A.D. TL 40,667i(19gq.

Acylhydrazones. It , i,:,'ntotionof C . -1

.:., \111.

Imine sutogales. In the Mannich reaction and cyanide addition, the use of these hydrazonesinstead of unstableimines is advantageous.rAllylation may also be performed with allyltrichlorosilanes.2

*. Pn.--{H

r..: .ichvdesare t, -'rident.l h

.

end nitro-

NHBz

*'nf'\). # rrJIX

Manabe,K., Oyamada,H., Sugita,K., Kobayashi,S. JOC 64,9054 (1999). : Kobayashi,S., Hirabayashi, R. "/ACSl2l, 6942(lggg\.

Acyl nitrates. Nitration.t Whenimmobilized,the acyl nitrateseffectmononitrationof areneswith goodregioselectiviry (6 examples, 86-lO0Eo). Rodrigues, J.A.R.,Filho,A.P.O.,Moran,p.J.S.SC29,2t6g (tggg\.

2-Acyloxy-4,6-dimethoxy-1,3,5-triazines. Esters.t Preparedfrom 2-chloro-4,6-dimethoxy-1,3,5-triazine and RCooH these compoundsundergotransacylationto alcoholsin the presenceof MgBr2. Kaminska, J.8.,Kaminski, Z.I.,Gora, J. S 593(l999). r.:

nrtriles.The

N-Acyl-N- (pentafl uorophenyl)methanesulfonamides. N-Acylation.t Amides are formed on reaction of these reagents with amines (36 cxamples,62-99Va). y Z56, 5943(2000). Kondo,K., Sekimoto, E.,Nakao,J.,Murakami,

tccnts are

Acylzirconocene chlorides. Acyl anion equivalents,t Addition of the title reagentsto enonesoccursin the 1,2mode. This Pd-catalyzedreaction provides unsaturatedhydroxy ketones.

l-Alkenyldichloroboranes

cl

Go.

Co'Zi

Alkenylsulfones. Alkenylation.: Frec cc'ptedby thesereagenL:

n CaHru

PhtvleA

CaHrz 88%

o

(R)-MOP =

? o

I Hanzawa,Y. Tabuchi,N., Saito,K., Noguchi, S., Taguchi.T. ACIEE 38,2395 ( I 999).

Alane.20,2 Reductionof phosphineoxides.tchemoselective reductionof phosphine oxidesin thepresence of sulfoxides areobserved withAlH, in refluxingTHF. 'Bootle-Wilbraham, A., Head,S.,Longstaff, J.,Wyatt,P.TL 40,526i (1999). Alkenylboronic acids and esters. 20, 3 2H-chromenes.t Condensation of alkenylboronic acids with salicylaldehydes constitutesa methodfor the synthesisof 2H-chromenes.

Ecrtrand, F..Quicler-Srrc. B

\'-A I koxycarbon;-l t trii-r1 N-Alkoxycarbonybit :hc transfer of the alkorr, Jcnvativesare readill prel

\ r.uh313. T..Nagaoka. ) . Tc

cHo + OH

(Ho)28-." R3 ll \*,

R2NH ' R - i -Z^-....'..1,a ll I

dioxane90

\AoA

R3

, c-Alkoxyalkyl)trincthyl R2

Allylamines.2 Acylium ion precursors such as carbinolamines alkenylboronates react with in the presenceof BF.,'oEt,. Benzylic amines are similarly obtained by replacing alkenylboronateswith the aryl analogues. Diels-Alder reactions,' A synthesisof 2.6-disubstituted(also more highly substituted) 3-cyclohexenolsis basedon cycloadditionwith preassemblage of alkadienolsand alkenylboronates. oxidation of the cycloadductswith Me.,No completesthe process.

Alkoxymethyl anion c :rJucc-fission of alkorrrr i.llcicnt alkenes.

Bno-SiMe3+

"/

lWang, F'inn,M.G.OL2,4063(2000). Q., rBatey,R.A.,Mackay,D.B.,Santhakum (1999\. ar,Y.JACSl2l, 5O75 rBatey,R.A.,Thadani, A.N.,Lough,A.J.JACS121,450(1999). 1-Alkenyldichloroboranes.20, 3 As dienophiles.t Thesereagentsare activein the Diels-Alder reactionat relatively low temperatures(e.g., * l0'). The adductsafford alcoholsreadily. tZaidlewicz. M., Binkul,J.R.,Sokol,W.JOMC 580,354(1999).

Alkoxycarbeniun io r()sether with Bu.NBFr{ * rth allvlsilanes and srlrI e

( iurcnb€rger. C.. Sreckhan. L \ jg':r.S..Suzuki. S..\amgm

(c-Alkoxyalkyl)trimethylsllanes

Alkenylsulfones. Alkenylation.t Freeradicalssuchas thosegeneratedfrom alkyl iodidesare interceptedby thesereagents.

c tI

lrtn O""'

?

. ? #taPh

t-Bu2O2 Phct A

o

^',,"

H

wo tl

57% (exo:endo=8'.2\

ulc oxides in

rBertrand, F.,Quiclet-Sire, B.,Zard,S.Z.ACIEE38,1943(1999).

ii\ Ialdehydes

N-Alkoxycarbonyl (triflyl)anilides. N-Alkoxycarbonylation.l Excellent leaving group properties of triflylanilides make the transfer of the alkoxycarbonyl residue to amines very efficient. Both Boc and Cbz derivatives are readily prepared. rYasuhara, T., Nagaoka, Y, Tomioka,K. ICS(Pl ) 2233(1999).

-R3 ^R,

n

Alkoxymethyl anian equivalents.t Photoinducedradical electron-transferconditions induce fission of alkoxymethylsilanes and the addition of ROCH2 groups to electrondeficientalkenes.

f..nvlboronates . obtained by

:

irighly substi,.Ladienolsand

k

, Irroccss.

t:

(cr-Alkoxyalkyl)trimethylsilanes.

r irt relatively

BnO_SiMe3+

-,1-,COOMe -l CN

P h - P h /M e C N - M e O H + CN

BnO:..2\,COOMe I CN 64%

Alkoxycarbenium ions.2 Low-temperature electrooxidation of the reagents ltogether with BuaNBFa-CH2C12)generatesthe carbenium speciesthat can be intercepted rrith allylsilanes and silyl enol ethers. Gutenberger, G., Steckhan, E.,Blechert, S.ACIEE37,660(1998). Suga,S.,Suzuki,S.,Yamamoto, A., Yoshida,l.JACS122,10244QC[l0).

Alkylaluminum chlorides

Alkylaluminum chlorides. Cyclization of alkcnylsilanes.r alkynesis effectedby EtAlClr.

Stereoselective intramolecular vinylsilyation of

.\sao,N., Shimada, T..Yamamtxr. l :Stoltz, B.M.,Kano,T..Corer.EJ I 'Ge. M., Stoltz,B.M.,Corer.t..J 0I 'Toro,A., Nowak, P, Deslongcham 'Yin. J.,Liebeskind, L.S../ACSt:l

SiMe3 trrArer-

+ cH?ct,

r-(\-4\

78.

Llln |

\/

|

l' |

Alkyl chloroformates. Phenols.t Cyclization t'f j the contextof a synthesisoi ('-rr

R

Fuganti, C.,Sena,S..tall{l ,ler9 cycloadditions. More examples of the RAlclr-catalyzed Diels-Alder reactions2r and [5 + 2]cycloadditions are shown in the following equations:

o

.'\a\zo\

o

A/. \-Al ) | i l T

cH2ct2

y'-or="

Me2PhsiV

78

Reductivebromination. _ rcagents(e.g.,isopinocampherlh

r'\,r\.ao\

^t),^) t t t l

MeAlCl2

Alkyldibromoboranes.

/---,\.

)

Alkyl (diphenylphosphono nctr (Z ) - a, F Unsuurated cslrn.rcactron)using theseestersls std rcasentsare (l) reactionof rPtrO .rlkoxycarbonylation of (PhOr-FO ,'t the methylphosphonate arr ro

ores

Me2PhSi

Kabalka, G.W.,Wu,Z..Yu.J. TL tt.

rl

V'

.rtlditionof baseto (PhO;,PtOr\lc .\ndo.K. JOC 64.8406r 1999,

-l l k1'l(3-hydroxyphenyl )diphco! Wittig reactions,t These rc rcactlon with carbonyl comF)or r!'mo\,edby base.

NIC-1lactone

-cN

f1

,pN

A,,,ot

(."'\

rr ""oo"y,-j-53,

Meooc \'^'/+T/ ;;. cH2ct223' to*v "1(v

:'oy,^-|X/,.

R=CHO

(+)-maritimol

75% TpMo(CO)2

TpMo(CO)2

6 : o.-z\

fi I I

i

ll

+ V* ll

EtArc".

;;;- -

o_\r n \{>

\/J\

R- v

hv

;i

ot)1

o'..FAR)-12

n

Ru.:c'll.M.G..Warren,S."/CSr Pr,, !{

{ Ik1'liminotris(dimethylamino ; Esters.t Transesterificatro :nrinophosphoranes. ll:rnkumiuan, P.,Verkade. J.G.J(X'a

{lk1'l methyl carbonates. ,Vethoxyarenes,t Phenoli u I)\lF. 150'). Comparingro drnr ,thcralkyl group largerthan prop; l'errrsa. A.. Selva,M.. Tundo.P. Zrd

Alkyl methyl carbonates

n; ..tl\ ation of

IAsao,N., Shimada,T.,Yamamoto, Y JACS121,3797(1999). rStoltz,B.M.,Kano,T.,Corey,E.J.JACS122,9044(2000). 'ce, M., Stoltz,B.M.,Corey,E.J.OL2,192'1(2000). 'Toro,A., Nowak,P.,Deslongchamps,P. JACS122,4526(2000). 'Yin, J.,Liebeskind, L.S."/ACS121,5811(1999). Alkyl chloroformates. Phenols.t Cyclization of 3,S-alkadienoic acids is readily effected, particularly in the contextof a synthesisof C-aryl glycosides. rFuganti, C.,Sena,S.Sf 1241(1999).

dr::Jrctions2l

Alkyldibromoboranes. Reductive bromination.t Aromatic aldehydes are converted into ArCH2Br by these dibromide)( I 2 examples,65-87Vo). reagents(e.g.,isopinocampheylboron G.W, Wu,Z.,Yu,J. rL4l,5161 (20N). Kabalka, Alkyl (diphenylphosphono)acetates. (Z)-or,pUnsaturated esters.t The condensationwith aldehydes(Emrnons-Wadsworth reaction) using these esters is stereoselective.Two convenientpreparativemethods for the reagentsare (l) reaction of (PhO)zP(O)Hwith bromoaceticesters in dichloromethane,(2)

: TES

I

.

.'-a-y' I _ Yl " .\n f

_{'v

(_., la^e

alkoxycarbonylationof (PhO)rP(O)Me with CICOOR. In the latter protocol, becauseanions of the methylphosphonateare very unstable,the acylating agents must be present before additionof baseto (PhO)zP(O)Me. .{ndo,K. IOC 64,8406(1999). Alkyl(3-hydroxyphenyl)diphenylphosphonium salts. Wittig reactions,t These reagents are water soluble. Product isolation from their rcaction with carbonyl compounds is also facilitated as the phosphine oxide can be removedby base. M.G.,Warren,S.JCS(PI ) 50-5(2000). Russell, .\ l kyliminotris(dimethylamino)phosphoranes. Esters,t Transesterification using enol esters as acyl donors is catalyzed by the rminophosphoranes. P, Verkade, J.G.JOCU,9063 (1999). Ilankumaran,

+ ,-aritimol

- -l-\

^-

- --\-\

Alkyl methyl carbonates. Methoxyarenes.t Phenols undergo O-methylation with methyl carbonates(K2COjI)\tF, 150"). Comparing to dimethyl carbonatethe unsymmetricalcarbonateswith the , 'ther alkyl group larger than propyl can be used in an open flask. A., Selva,M., Tundo,P, Zordan,F.5L272 (2000). Pcrosa,

I -Allylb€nzotriazole

I -Alkyl-3-methylimidazolium

salts. Reaction media- The low-melting salts (ionic liquids) are now routinely employed as reaction media. 1-Butyl-3-methylimidazorium tetrafluoroborate and hexafluorophos_ phate are particularly popular. Besides those described in various sections of this volume, their use in the Ni(acac)r-cataryzed autoxidation of aromatic aldehydes,r reduction of aldehydeswith BujB,2 wittig reactions,3 Diels-Alder reactions4-uy u" mentioned. Many reactlons are acceleratedand the workup procedure for most of them is facilitated. By using (PhH)aRuoBFaas catalyst, the hydrogenation of arenes in reacilon media containingionic liquid and water has been described.5 Friedel-crafts and related reactions conducted in a dialkylimidazolium haloaluminate appear in increasing frequency. The sptitting of ethers with simultaneous acylation to afford alkyl benzoatesis a recent example.6 IHowarth,I. TL 41, 6627(2000). 'Kabalka, G.W.,Malladi,R.R.CC 2191(2000). rl-e Boulaire, V, Gree,R. CC 2195(2000). aFischer, T., Sethi,A., Welton,T.,Woolf,J. TL 40,793 (1ggg). 5Dyson, P.J.,Ellis,D.J.,parker,D.G.,Welton,T. CC 25'(tr)gg). 6Green, L., Hemeon, I., Singer,R.D.Zt 41, 1343(2000). Alkyl methyt sulfides. Pauson-Khand reaction,t The surfides have catalytic effects on both rntramore_ cular and intermolecular version of the reaction. rSugihara, T.,Yamada, M., yamaguchi, M., Nishizawa, M. 5L771 (rg9g\.

,rN--'{

G"

Rrrntzl\..{R.ScrJr

{llrlbomn

rtageots. Hommllylic anit :::lmc'thrI v lr Itrenz:Jdr Reaction tirt at ::tc .uh\tratL'\Sothat n

-q"

R = H

R = M N-Alkyl trifluoroacetaldehyde imines. Fricder-crafts reaction-t r-Aryr-2,2,2-trifluoroethylamines are readiry formed from the Lewis acid-cataryzedreaction of cF,cH:NR with activated arenes (e.g., indole).

$Pentcnok. \lL : :hc adductsgtrei l-q

rGong,Y.,Kato, K., Kimoto,H. SZ l05g (2000). Allylbarium reagents. Preparation, I The suitabre form of BaI2 for reactron with ailyilithiums is obtained from stirring Ba with 1,2-diiodoethane in ethercontarningNa2S"Oa. IDuval,8., Zoltobroda, y. TL 41,33:.(2000\. G.,Langlois, I -Allylbenzotriazole. 2-Alkyl-1,3-butadienes-.r This reagent undergoes alkyration at the ct-position. By reaction with trimethylsilyl chloride, a valuable four-carbonbuilding block is obtained. The latter compoundon further alkylation and pyrolysrsgives 2-arkyl-r,3-butadienes.

i :c migration of an oxymethyl group to afford spirocyclic productsTis rr'.rlrzedhr erposing dibenzodioxepinsto AlCl. Other Lewis acids are less efficrent.

IGhiaci, M., Asghari,J. SC 29. 9?.r , 2Suwa, S., Sakamoto,T., Kikugar:_, 'Suarez. A.C.TL40.3523 r ld9, aTang,J., Liu, X.-F., Zhang, L.-) . )t, )Rebeiro, G.L., Khadilkar, B.Il. SC J 6Moghaddam, F.M., Dakamin. It.G j TColeman, R.S., Guernon,J.M.. Roh oMa, S., Wei, e. EJOC 1939 (20m, 'Song, Y.-S.,yoo, 8.R., tre. G.-H . Jr roSudo, T., Asao, N., Gevorgyan.\.. )i " Lee, C.W TL 40, 2461 (199q ',xi,z.,Li,P. A C I E E 3 9 , 2 9 5 0( t m ,

Aluminum hexafluoroantimooe plactones.t Acidchlondc

o\ct R R

-{-l&R /:/

L-

o''''-*-A H cH2c'2 RR

\$-/--

b...-J-

R = Me

gSYo

Hydrosilylation.e''' Traditional methods of hydrosilylation involve the use of transitionmetal catalysts.However,Lewis acidssuch as Alclr also show such reactivity. Diels-Alder reactions.tt Addition of Alcrr to r-ethyl-3-methyrimidazolium chloride forms a chloroaluminate ionic liquid. This substance acceleratesand enhances the selectivityof Diels-Alder reactions. cyclopentadienes.t2 Replacement of the metar moiety of zirconacyclopentadienes that are readily available from alkynes by the [RCH] unit of an aldehyde is accomplished by an AICIr caralyzedreaction.

Aluminum tris(2,6-diphenylphco AAolreaction o,p_Unsaru condensation with phCHOat the11

t

l

\z\ l_

^,-\,/ r (

.ZrCp2 + \ R

R Atcl3

R'-CHO

K.

R l

ll >-R'

R--Y

R

-

-\-"--\rcHo

l R i

I H\-,

rNelson, S.G.,Wan, Z.,peelen,T.J.. Sp

2-chloroallyl sulfuxides.s Allenyl sulfoxides undergo addition of HCr in the presenceof AlCl.-HrO.

K

*

|

r

-\,.\-\ I cHo

a-Alkoxybutylation.2 A rela1.r of enolatesin THF-toluene mrxture. .

Aluminum tris(2,6-diphenylphenoxide)'ATPH

-_r) /'aAcoolt'tu

t7

rGhiaci, M., Asgharl,J. SC 29,973 (1999). 2Suwa,S., Sakamoto,T., Kikugawa,Y. CPB 47,980 (1999). 3Suarez,A.G. rL 40, 3523 (1999). aTang,J., Liu, X.-F., Zhang,L.-Y., Xu, X.-L., Zhang, P.-R.SC 30, 1657 (2000). sRebeiro, G.L., Khadilkar, B.M. SC 30, 1605 (2000). 6Moghaddam,F.M., Dakamin, M.G. TL 41,3479 (2000). TColeman,R.S., Guernon,J.M., Roland,J.T. OL2,271 (2000).

8Ma,s.,wei,Q.EJoc 1939(2ooo). eSong, LN.OM18,3109(1999). Y.-S.,Yoo, B.R.,Lee,G.-H.,Jung,

e:::. ,)(hoformate \:. .:- ,rrcobtained

IoSudo,T., Asao, N., Gevorgyan, V., Yamamoto,Y. JOC 64,2494 (1999). I rLee, C.W. TL 40,2461 (1999). t2x| 2., Li, P.ACIEE 39, 2950 (2ooo).

r. .. r. ehloroalumi1 ; ' ' . r h c ne x p o s e d s r . , . r i p r o d u c t siT .- -'tlicient.

Aluminum hexafluoroantimonate. plactones,l Acid chloridescondense to give B-lactones. with aldehydes

oY"'

+

O tt ,{

Al(SbF6)3 / i-Pr2NEt CHzClt 25i

-

H- \.,-\-.

Vo L-l

9rn

HN

93Yo I Nelson,S.G.,Wan, 2., Peelen,T.J.,Spencer,K.L. TL 40, 5635 ( 1999).

r HCI in the rr. .rc the use of p., ..r'h reactivity. -:::-t:r Iirnidazolium a:.::-'.irfldenhances

ATPH. 20,14-15 Aluminum tris(2,6-diphenylphenoxide), in the carbonylcompoundsshowregioselectivity Aldol reaction a,B-Unsaturated with PhCHOat the1-positionafterenolaluminationwith ATPH.I condensation

;^,*Til

-(---J=rcHo

^a-

63yo

. .lopentadienes o:r.1L\.:- :. llccomPlished

A-^-\

ATPH ;

84To LDA,PhCHO

cHo a-Alkoxybutylation.2 A relay attack of epoxides has been observed in the reaction of enolatesin THF-toluene mixture. The coordinatedTHF is involved.

IE

1-[c'(Amino)arylmethyl]benzotriazoles

Ammonium molybdate. a-Ketols.t Epoxides are co at room temperature(l I examplc

o

*Jl-/*' t ^ \r"-\.''""

LDA' THF

| R,\'--R'

orr" (^\1" V

oh t 4) \-Pt.

I Ismail.N.. Rao.R.N.CL 841rll-::r. Antimony.

o'

admixture of ATPH with Addition to aromatic nuclei,3 complexes formed upon fucoclaresusceptibletoattackbynucleophiles(e.g.,enolates,/-BuLi)atanucleal position.

" oo^"ffi)co^".od oH

cr

o'.r

v

15To

43Yo

.{l Homoallylic alcohok. mediatedby activated Sb-KF Li. L.-H.,Chan,T.H.rl 41.5ffic ': Antimony(V) fluoride. Carbonyl chloride fuoridc. rreatmentwith SbFs.

K.O.JFC9l, lrr' Hoge,B.,Christe,

A rcnediazonium o -benzeoedis Aryl halides,' Decomprxrt emmoniumhalide furnishesan I

rsaito. S., Shiozawa, M., Nagahara' T', Nakadai, M"Yamamoto' H' "/ACS 122'7841 (2000)' 2saito. S.,Yamazaki,S', Shiozawa,M., Yamamoto,H' Sf 581 (1999)' rSaito. S., Sone,T., Murase, M., Yamamoto, H' 'IACS 122' 10216 (2000)'

Aluminum tris(2,6-diphenylphenoxidelalkyllithium' are ^y-stannyl ketones2derivedfrom cycloalkenones Fragmentation 1-Iodor and areamphiphilic' ketones.The reagentcombinations convertedinto unsaturated

I '

ATPH / BuLi

-

PhMe - Et2O

a-'/ I

w

o 93% rKondo,Y., Kon-i, K., Ooi, T., Maruoka, K TL 40,9041(1999). K. ACIEE39,414(2000) rKondo,Y, Kon-i, K., Iwasaki' A., Ooi, T', Maruoka.

1-[ot-(Amino)arylmethyl]benzotriazoles with these feagents to Aminobenzylation of phenols,t Sodium phenolates react

Blrbero.M., Degani,1..Dugherr"S

{renesulfonic acids. .Vannich-typereaction. S j\c!-llent catalystsfor the con&o

4>'u.OMe * PhcHo + ll \z

NHz

furnish Mannich-tYPeProducts. IKatritzky,A.R.,Abdel-Fattah,A'A.A',Tlmoshenko'D'O''Belyakov'S'A''Ghivirigia'I'Steel'PJ' JOC 64,601r (1999).

\l:nabe. K.. Mori. Y. Kobava-shr. S

Arenesulfonicacids

Ammonium molybdate. a-Ketols,t Epoxides are converted to ketols by ammonium molybdate tetrahydrate at room temperature(l 1 examples,92-96Vo). rlsmail,N., Rao,R.N.CL844(2000). Antimony.

L

\TPH with l a nuclear

Homoallylic alcohols.t Allylation of carbonyl compounds in aquebus media is mediatedby activated Sb-KF. rLi, L.-H.,Chan,T.H.rt 41,5009(2000). Antimony(V) fluoride.

-.,

oH

\. \a\" tl 15o/o

Carbonyl chloride fluoride.t treatment with SbF5.

Phosgene exchanges one of its chlorine atoms on ffr'

fil

lHoge,B., Ch-riste, K.O.JFC 94,107(1999). Arenediazonium o-benzenedisullfonimides. Aryl halides.t Decomposition of these salts (1) in the presence of a quaternary ammonium halide furnishes aryl halides.

n , o ""dirr\

,.. .r,kcrrones t

_

N lt ArN,* -ls:--'.9) o- \b (1) Barbero, M., Degani,I., Dughera, S.,Fochi,R. JOC 64,3448(1999). Arenesulfonic acids. Mannich-type reaction,t Sulfonic acids bearinga long chain (e.g., dodecyl) act as !-\cellentcatalystsfor the condensationin water.

:r:--e reagentsto

l,.J. . .t e e P r . : . : : . r . 1S

\lenabe, K., Mori, Y., Kobayashi,S. Sf 1401(1999).

20

B-(2-lvido-2-propenyl)-1,3,2-dioxoborinane

Arylboronic acids. Glycosylation,l The glycosylationof unprotectedsugarscan be accomplished whentheyareactivatedby arylboronicacidssuchas L.

Z\X o l l l ott')t\

Barium permanganate.

H

Oxidation,t Solvenrthis reagentor MnOl.

'ry

rFirouzabadi, H., Karimi.B . Al

(1) Benzenesulfenyl chloridcN-Arylimidazoks.2 complex in the air.

Arylation of imidazoles is efficiently catalyzed by a copper

Cyclnpropane ring q regioselectivityof ring open

rOshima,K., Aoyama,Y. JACS121,2315(1999). 2Collman,J.P.,Zhong,M. OL 2, 1233(2000).

Il /\

Arylp-nit to theiraryl estersby thesereagents. aminoacidsareconverted Aryl esters.t Protected rPudhom, (1999). T. TL 40,5939 K.,Vilaivan, 2.3-Azetidinediones. with aminesgivespeptides. Pepti.des,t Reactionof theheterocycliccompounds

o\-.R' ^Jf,

tJ

ETOOC'

-oMe 'OM.

PhS PhS(

Graziano, M.L.,Iesce.\l.R . C

3-Benzenesulfenyl-2-(N "#np

N=N

R

Acetals.t l,3-Diols can be prore. cyclic acetalsis by catalytic hydrogenar is instigatedby the releasedpriman hrd

OH

OH

*

cHo

\r^o

N=Ni 70To rPowell,N.A.,Rychnovsky, S.D."/OC61.:Ol

lKatritzky, A. R.,Mehta,S.,He,H.-Y.,Cui,X. JOC 65,4364(2000). Benzyltriethylammonium

1 I/-Benzotriazol-1-yl mesylate. N-Mesylation.r Mesylation of an amine in the presence of hydroxyl groups is possible with this reagent.Primary amines are more reactive than secondaryamines.

tetrathiorml Disulfi.des. Alcohols are con\.enc catalyzed) and reaction with the reagc organic disulfides are cleaved by tlr r trappedby Michael acceptors.r

rKim,S.Y.,Sung,N.-D.,Choi,J.-K.,Kim, S.S.TL 40,117(1999).

(1 II-Benzotriazol-1 -ylmethyl)trimethylsilane. Homologation of carboxylic aci.ds.t A reaction sequence for the homologation starts from a reaction of BtCHrSiMe., with RCOCI. After O-triflation, treatment with either TsOH and then BuaNF (aliphatic series) or NaOMe then HCI (aromatic series) completes the transformation.

fol^ot v

lBnrEr.\i

rKatritzky,A. R., Zhang,S.,Fang,Y. OL 2, 3789(2000).

O - (Benzotriazol- 1-yl)- N,N,N',N' -tetramethyluronium tetrafl uoroborate. Ether cleavage.t This reagent catalyzes cleavage of THP, silyl, and 4,4'dimethoxytrityl ethers. rRamasamy, K.S.,Averett,D. SL709(1999).

Cleavage of propargyl carbamaratreatment with I equiv of the terarh irradiation.

rSrnha, S.,Ilankumaran, P.,Chandrasekaran S I Prabhu, K.R.,Sivanand, P.S.,Chandrasc\ar ' Sinha,S.,llankumaran, P.,Chandrasekara S

Benzyltrimethylammonium

Benzotriazol-1-yl alkyl carbonate. Amides.t Reaction with a carboxylic acid followed by aminolysis leads to amides. rl-ee,J.S.,Oh, Y.S.,Lim, J.K.,Yang,W.Y.,Kim, I.H., Lee,C.W.,Chung,Y.H.,Yoon,S.J.SC 29, 2547(1999\.

diphenltpt Stille coupling.t The title compc residues.On precipitatingRrSnop(O rF are facilitated.

Zhang,S.,Marshall,D., Liebeskind. L.S..rOC

Benzyltrimethylammonium

lf":

:

E: -' t-__'

I -benzotriazolyl)pyrrolidinones :rezole. and 2,5-dimethoxY-2,5i.r nucleophiles.

4-Benzyloxybutanal. Acetals,t 1,3-Diols can be protectedas substituted1,3-dioxanes.Cleavageof the cyclic acetalsis by catalytic hydrogenation in which an intramolecular exchangereaction is instigated by the releasedprimary hydroxyl group.

R

ol-ru\\Y R

I i l

diphenylphosphinate

aar'-r--

R'

3r or

*

9HO

\,,^orn

*r'Y*' H2 / Pd(OH)2-C

+

oLo,"

N=N

rPowell, N.A.,Rychnovsky, S.D."IOC64,2026(1999).

r :.. nrcsenceof hydroxyl groups t ' . . : . i r \ d t h a ns e c o n d a raym i n e s .

\: " .L'quencefor the homologation \ir!-r O-triflation, treatment with )r x \ :t )\tc. then HCI (aromatic series)

oni u m tetrafl uoroborate. . rj.rlc of THP, silyl, and 4,4'-

ll, Lr

: hr aminolysisleadsto amides. \\ . Chung,Y.H.,Yoon,S.J.SC 29,

Benzyltriethylammonium tetrathiomolybdate. Disulfides. Alcohols are converted to disulfides on activation with Dcc (cucl catalyzed) and reaction with the reagent (9 examples, 45-ggZo).t On the other hand, organic disulfides are cleaved by the title reagent and the resulting thiolates can be trappedby Michael acceptors.2

(Yo' v

CuCl,DCC

O.^t"'-O

lBn(Et)3Nl2MoSa

88%

cleavage of propargyr carbamates.3 The amino-protecting group is removetl on rreatment with l equiv of the tetrathiomolybdate salt in MeCN with urtrasound irradiation. p, Chandrasekaran, Sinha,S.,Ilankumaran, S. I55, l4i6g 01ggg\. : Prabhu,K.R., Sivanand, p.S.,Chandrasek alirn,S.ATCIEE39, 4316(2000). 0lggg). p.,Chandrasekaran, Sinha,S.,Ilankumaran, S. ZZ 40,.7il Benzyltrimethylammonium diphenylphosphinate. stille coupling.l The title compound is an effective scavenger of organotin rcsidues.on precipitating Rjsnop(o)ph2 the cu-catalyzed Stilre coupling reacrions ere tacilitated. Zhang,S.,Marshall, D., Liebeskind, L.S.JOC 64,2jg6(1ggg).

f,f'-BiE

l, l'-Binaphthalene-2.2'-diol. BINOL

Benzyltrimethylammonium tetrachloroiodate. Hydroximoyl chlorides.t Chlorination of aldoximes by this reagent at room temperatureis rapid. rKanemasa. A., Kakinami,T. 256, 1057(2000). H., Kamimura, S.,Matsuda,

Benzyltriphenylphosphonium peroxodisulfate. Oxidation,l Primary alcohols are oxidized to aldehydesunder solvent-freeconditions with this reagent and aluminum chloride as catalyst. Reaction in the presenceof other Lewis acids including FeClr, BiClr, andZnCl, are less efflcient. rHajipour, S.E.,Adibi,H. CL 460(2000). A.R.,Mallakpour,

Benzyl N-vinylcarbamate. Arylethylamines.t The title compound is transformed into an alkylboronic acid via hydroboration and its Suzuki coupling with ArI affords ArCH2CH2NHCbz. rKamatani, L.E.JOC 64,8743(1999). A., Overman,

Binaphane. Asymmetric hydrogenation r (R,R)-Binaphane ( I ) is preparedfrom l.l' -bi-2.2'naphthol in five steps. Its Ru complex is useful for asymmetric hydrogenation of trisubstitutedenamides.

f

1,1'-Binaphthalene-2,2' -iliol (modifed > Cyanations, Aluminum compleres with diarylphosphine oxide groups posses cyanation of aldehydesrand imines: '*'irh

in a manner analogous to the Reisscr asymmetric Strecker synthesis is apphc reactivity of MejSiCN than HCN in rlre g

catalytic amount while supplying stoichro

2\/

(A

C(

Al.dol transfer.a An aluminum con replacementof the carbinol moiety of an I the aldol and an aldehyde in dichlorot transformation.

rHamashima, Y.,Sawada, D., Kanai,M.. Shrbc rTakamura, M., Hamashima, Y, Usuda,H.. K:a 'Takamura, M., Funabashi, K., Kanai,M.. Stxh 'Simpura,L, Nevalainen, V.ACIEE39.3.111 r!

(1)

lXiao,D., Zhang,Z.,Zhang,X. OLl, 16'79(1999).

1,1' -Binaphth alene-2,2' -diol' BINOL. Resolution.t The cyclic boronate ester derived from racemic BINOL and BHl SMe2 preferentially forms a diastereoisomerwith r-proline, thereby (R )-BINOL can be isolatedby crystallization.On decompositionof the complex(S)-BINOL is recovered. rShan, 2Z., Xiong,Y.,Zhao,D.255, 3893(1999).

I,l' -Binaphth alene-2,2' -diol-galliurn/lld 2-Aryloxy alcohols.t meso-Epoxrh Ga-Li linked BINOL complex with high

rMatsunaga, S., Das,J., Roels,J., Vogl.E.\l . M. "/ACS122,2252(2000).

1,1' -Binaphth alene-2,2' -diol-porassiurn/ Addition to imines.t The hererd (l-PrO)1Yb and r-BuOK catalyzes rhe ar N-phosphonimines.

rYamada, K., Harwood,S.J.,Griiger,H.. Shrb.s

I,l'-Binaphthalene-2,2'-diol-potassiurn/yttrrbium complexes

\rmcs by this reagent at foom

:f' :o57(l0OO).

h - : Le

:i t\ des under solvent-freeconditions Rcaction in the presenceof other

1,1'-Binaphthalene-2,2'-diol (modified)-aluminumcomplexes. cyanations. Aluminumcomprexes of BINoLs (1) that are armedat c-3 andc-3' with diarylphosphine oxidegroupspossess bothLewis acidandbasecenters.Asymmetric cyanationof aldehydesr andimines2with Me.SicN, andof quinolinesandisoquinolines3 in a manner analogousto the Reissertreaction is successful(ee- 7G-902o).The asymmetricstrecker synthesisis applicableto conjugated.aldimines and the higher reactivityof MersicN thanHCN in the presence of l0 molToof phoH enablesits usein catalyticamountwhile supplyingstoichiometric HCN asthecyanidesource.

.:llclent.

t,,

tr.:' .' :nrcd into an alkylboronic acid via r:: -:. \rCH.CH.NHCbz.

(1)

'r R

I , is preparedfrom 1,1'-bi-2,2''r asvmmetric hydrogenation of

Aldol transfer.a An aruminum complex of BIN'L is capable of cataryzing the replacementof the carbinol moiety of an aldol. Thus, addingthe complex to a mixture of the aldol and an ardehyde in dichloromethane at room temperature completes the transformation. Hamashima, Y.,Sawada, D., Kanai,M., Shibasaki, M. JACSli2l, 2641(19gg). rThkamura, y., Usuda,H., Kanai,1,f., M., Hamashima, if,ii^"ti, M. ACIEE 39,1650(2000). 'Takamura, M., Funabashi, K., Kanai,M., Shibasaki, frl.]aCS 122,6327 (2000). rSimpura, L, Nevalainen, V.ACIEE39,3422(2000\. l,l' -Binaphth alene-2,2,-diol_galiumlithium complexes. 20,24_25 2-Aryloxy arcohors.t meso-Epoxrdes are op"n"o by phenors in the presence of the Ga-Li linked BINOL complex with high enantioselectivity.

#1))13?ri;iTirl;;fr*,,,

(':

. ctl tiom racemic BINOL and proline,thereby(R )-BINOL can -,'nrplex(S)-BINOLis recovered.

J, Vogr, E.M, yamamoto, N.,rida, r, yamaguchi, K.,Shibasaki,

1,1'-Binaphth alene-2,2,-diol_potassium/ytterbium complexes. Addition to imines.) The heterobimetallic complex derived from BINOL, ll-PrO).,Yb and l-BuOK catalyzes the asymmetric reaction between nitroalkanes and .V-phosphonimines. Yamada, K., Harwood,S.J.,Grriger,H., Shibasaki, M. ACIEE 3g,3504(1999).

l.I'-Binaphthalene-2,2'-diol-titanium complexes

1,1'-Binaphthalene-2,2'-lliol-titaniumcomplexes. 15,26-27;16,24-25;17,28-30; 18, 4344; 19, 25; 20,25-27 Enantioselective isomerization.t Epoxides of enol esters provide chiral a-acyloxy ketones and chiral starting materials. 4-Substituted butenolides, 2-siloxyfurans react with aldehydes2and with imines3 at C-5 to give chiral products. The hydroxyalkylbutenolides formed can be incorporated into the catalyst system thus rendering the aldol reaction autoinductive. Chiral sulfuxides.a A catalytic oxidation of organothiomethylphosphonatesenables the preparation of enantiomerically pure sulfoxides. a,a -Disubstituted amine*s Addition of two Grignard reagentsto a nitrile leads to the products. If a chiral BINOL-Ti complex is introduced in between the additions, the oroductsare enantioenriched.

BnO_CN

-J-'t 99Va

Hydroformylation.l A poll'mer-r catalyst for asymmetric hydroforml L propene)to afford branched aldehr'&s.

reachable). Conjugate additian. A phosphoramidite ligand (1) is useful for chiral induction during reactionoforganozincreagentswithenonesrand4.4-disubstituted 1,5-cyclohexadienonesain the presenceof Cu(OTf)2.

o

ot

Ph

o ' F P-N

o

/""'

Ph

(1)

Allylic tlisplacements.s The mixed phosphite of BINOL and phenol serves as a ligand to make up a catalyst with [(cod)IrCl]2 for the allylic substitution. Remarkable rate enhancement and increase in yield and ee are realized when the reaction is performed with BuLi-ZnCl2 also. Hetero-Diels-Alder reaction.b In the cyclocondensationof the Danishefsky diene and aldehydes in the presence of 2, a remarkably high asymmetric amplification is realized.

C h o n g ,J . M . , S h e n ,L . , T a y l o r ,N . J . . I A C Sl : rvan der Berg, M., Minnaard, A.J.. Schudd I-'eringa,B.L. JACS 122, I1539 (2000r. 'Naasz, R., Arnold, L.A., Pineschi,l\t.. Kclk ' l m b o s ,R . , B r i l m a n ,M . H . C . , P i n e s c h r\.l . I 'Fuji, K., Kinoshita,N., Tanaka,K.. Karahc 'Furuno, H., Hanamoto,T., Sugimoto.)'.. lru -Nozaki, K., Shibahara,F., Hiyama. T. C1.64

I,l' -Binaphth

alene-2,2' -iliyl siloxan-

CyclosilylationI

Yttrocene

compounds while

incorporating

asymmetric induction is poor.

I

cr

a sll

I,l'-Binaphthalene-2,2'-diylsiloxane

;:o '='@

3l

O' P " " ^

o' ' o- l I 3 vu (2)

rr .

'lrhasaki. M. JACS 122,6506(2000).

Hydroformylation.T A polymer-supported (RS)-BINAPHOS complex 3 serves as catalyst for asymmetric hydroformylation of gaseoussubstrates(e.g., 3,3,3-trifluoropropene) to afford branched aldehydes. I .. ., r.rn\ I group donorsof an enone. n:J:, rhosphoramiditeligands containing ,\rth (cod)2RhBFain asymmetric r: ar.: r -.uhstitutedacrylic esters(ee ) 997o p:.: I i. usefulforchiralinductionduring in 1.5-cvclohexadienonesa { : .::.uh\tituted

(3)

,

pi::: ,'1 BINOL and phenol servesas a x ':.; .rllrlic substitution.Remarkablerate i:.:../iJ *hen the reactionis performed

Chong,J.M., Shen,L., Taylor,N.J. JACS 122, lB22 (ZOOO). :van der Berg, M., Minnaard, A.J., Schudde,8.p., van Esch, J., de Vries, A.H.M., de Vries, J.G.. Fcringa,B.L. JACS 122, I I 539 (2000). ')iaasz, R., Anrold, L.A., Pineschi,M., Keller, 8., Feringa,B.L. JACS l2l, I 104 ( 1999). ' l m b o s ,R . , B r i l m a n ,M . H . G . ,P i n e s c h iM , . , F e r i n g aB , .L. OLl,623 (lggg). 'Fu1i, K., Kinoshita,N., Tanaka,K., Kawabata,T. CC 22gg Oggg\. Furuno,H., Hanamoto,T., Sugimoto,Y., Inanaga,J. OL2,49 (2000). ).iozaki, K., Shibahara,F., Hiyama, T. CL 694 (2000).

l. l' -Binaphth

:l .- ':J!'nsationof the Danishefskydiene rt,^ . high asymmetric amplification is

alene-2,2' -diyl siloxane.

cyclosilylationr compounds while

Yttrocene incorporating

esymmetric induction is poor.

1 catalyzes the conversion of a silyl group from

polyenes to cyclic

hydrosilane reagents. However,

-methyl)tindibromide Bis(1,1'-binaphthalene-2,2'

\L

^'"'@/\

9H

"-..P'--' Y'1,,2

,u-*r'

\z

Bis(acetonitrile)(1,5-cyclooctadi€trc ft

' Muci,A.R.,BercaqJ.E.TL 41.7609(200U.

Aryl transfer. The aryl group of . the influence of the ionic Rh complex,

Bis[1-(1,1'-Binaphthalene-2,2'-methyl)-3-methylimidazol-2,2'-ylidene]palladium(II) iodide. Heck reactionr The carbene complex 1 is very stable to air, water, and high temperature. It also survives silica gel chromatography. Preliminary investigations of I indicateits catalyticactivity in the Heck reaction.

\\ tM1

Bis(acetonitrile)cyclopentadienyl( trio tetrafluoroborate.

Slugovc, C.,Ruba,8.,Schmid,R., Kirchr

tl tt \J

I Oi, S.,Moro,M., Fukuhara, H., Kawanrd

Isomerization Efficiency for tb ketonesby intramolecular redox isomcr CpRu(PPhj)2Cl-NH4PF6l,but there is d the substrates.The catalyst is readily pr

t.r/*-

tt-

(1)

I Clyne,D.S.,Jin,J.,Genest, E.,Gallucci,J.C.,RajanBabu,T.V. OL2, ll25 Q0O0). Bis(1,1'-binaphthalene-2,2'-methyl)tin dibromide. Enantioselective benzoylation.t The title compound 1 catalyzes selectivebenzoylation of racemic 1.2-diols.

n'\-\Z'r -

Ph/-voH+Phcocl

/'

jlwasaki, F.,Maki, T., Onomura,O.. Nat st

(1)

oH

phr''t

rffi v\?

|

(1)

,,B r

sri

Br

Bis(acetonitrile)dichloropalladium( tIl 25-26; 17, 30-3 I ; 18, 4445: 19, 26 Thia-Claisen rearrangemenlt h chiral bicyclic thiolactams via a rhio effected with assistanceof (MeCN).pdC

,n,10-Jh ""oJr*F\ S.....^/.Ph

Na2CO3 THF - H2O (50 : 1)

Allylic displacernents. For achieri alkenols to form 2-vinylpiperidinc , VeCN)zPdClz is needed because tl: throughout the reaction.

Bis(acetonitrile)dichloropalladium(tr)

9H :

v

oH +

-;-OBz ph..' \./---

l ph'

-\./- -OH

i

(er 92:8) 41o/o

J

rlwasaki,F.,Maki, T., Onomura,O., Nakashima, W., Matsumura, Y. JOC 65,996 QUn).

Bis(acetonitrile)(1,5-cyclooctadiene)rhodium(I) tetrafl uoroborate. Aryl transfen The aryl group of ArSnMej is transferred to N-sulfonyliminesr under the influence of the ionic Rh complex. lm ida zol'2,2'-ylidenelpalladium(II) .rable to air, water, and high PreliminarYinvestigationsof I

I T:

r Oi, S.,Moro,M., Fukuhara,H., Kawanishi,T., Inoue,Y.fL4,9259 (1999').

Bis(acetonitrile)cyclopentadienyl(triorganophosphine)ruthenium(I) tetrafluoroborate. Isomerization

Efficiency for the transformation of allyl alcohols to saturated ketonesby intramolecular redox isomerization is improved by using these complexes [vs. CpRu(PPh)2Cl-NH4PF6l, but there is the disadvantageof limited substitution patternson the substrates.The catalyst is readily preparedfrom RuClj.3H2O. : Slugovc,C., Ruba,8., Schmid,R., Kirchner,K. OM 18,4230(1999).

r tt.2. ll25 (20O0)-

ldt.

r'.

::J I catalYzes setective benzoYla-

Bis(acetonitrile)dichloropalladium(Il). 13, 33, 2l l, 236; 14, 35-36; 15, 28-29; 16, 25-26; 17,30-31; 18, 44 45; 19, 26 Thio-Claisen rearrangement.t Introduction of a side chain to the c-position of chiral bicyclic thiolactams via a thio-Claisen rearrangement at room temperature is effected with assistanceof (MeCN)2PdCl2.

,,oJ-\

Ph,',(

|

|

)-Nvz\ MeoJ 5=.-r1--tn a

\

V' 2

J":tr (exo: endo 3:1\ 650/o

/

\,

(MeCN)2PdCl2

Br

Na2co3

Sn

Br

lHf_tr2v

( 5 0; 1 )

Allylic displacements. For achieving dehydrative cyclization of N-Boc-7-amino-2alkenols to form 2-vinylpiperidine derivatives,2 only a catalytic amount of ,\{eCN)2PdCl2 is needed because the Pd(II) species maintains its oxidation state throughout the reaction.

Bis(acetonitrile)dichloropalladiun(II)

OBn

OBn MOMO

MOMO

(l\4eCN)zPdClz THF 25'

rWatson,D.J., Devine, P.N., Meyers..{.1. II, rYokoyama, H., Otaya, K., Kobayashr. H. (2000). rLautens,M., Renaud,J.-L., Hieb€n. S. ./..1( rYang, F.-Y.,Wu, M.-Y., Cheng,C.-H- l.f CS sFielder,S., Rowan, D.R., Sherbum. Il.S .{(

OH fung opening of 1,4-oxa-1,4-dihydronaphthalenewith R2Zn proceedsin the presence of (MeCN)2PdCl2to afford cls-2-alkyl-1-hydroxy-1,2-dihydronaphthalenes.l Acylboration, Allenes are functionalized to give 2-acylallylboronates on reaction and acyl chlorides.a with bis(pinacolato)diboron

R + R"COC| + R'

]-o. |

l-d

p-L B-B

I 'o1-

Bis(allyl)dichlorodipalladium.

20. l9

Allylic displacements. Glycine dr with an allyl carbonate.rBINAP medral is rapid. The reaction with 2-bromo-1.3{ren Similarly, 3-bromo-3-alken-I -ynes are s butaLrieneproducts.aIn this reaction.

(tr4eCN)zPdClz

addedlieand.a

PhMe 80"

MeO Stille coupling.s An expedient synthesisof [6]dendraleneinvolves coupling of 2,3bis(trimethylstannyl)-1,3-butadienewith 3-iodosulfolene and pyrolysis. A lesser amount of [8]dendraleneis also produced.

Ph'\
97o/o

:,,u: silica is useful for dehalo: rnrolving allenYlketonesand

BisIchloro(1,5-cyclooctadiene)iridium(I)]. Aziridines.t Aziridines are obtained in one step from aliphatic amines, aldehydes, and ethyl a-diazoacetatein the presenceof [(cod)IrCl]2. Enynes.2 l-Alkynes are dimerized. T\e (E/Z) ratio of the products is strongly dependent on the phosphine ligand that is added. lert-Alkylalkynes afford 1,2,3butatienes.

lFl

:\

,/o\./ \\il

,rt

t., tff)0).

Ph2(Me)Si, Phr(Me)Si

R

\

[(cod)lrcl]2- R3P Et3N/ cyclohexane

\

\-gHg;1vs;p6,

R3P= Ph3P

95o/o EIZ 98:2

R3P= Pr3P

62Yo EIZ 11 :89

Bis[chloro(1,5-cyclooctadiene)rhodium(I)]

N'N-Disubstituted hydroxylamines.3 The k complex, together with BINAp, forms a homogeneoushydrogenation catalyst for nitrones.

['ood,

rKubo,T., Sakaguchi, S.,Ishii,y. CC 625 eOO$. 2Ohmura, T.,Yorozuya,S.,yamamoto,y., Miyaura,N. OM 19,365(2000). 3Murahashi, S.-I.,Tsuji,T., Ito, S. CC 4Og(2000).

CC Ga - ror

Bis[chloro(1,5-cyclooctadiene)rhodium(I)]. Functionalization ofunsaturated compounds. Hydroacylation ofalkynes, allenes, and alkenesusing 2-hydroxyaraldehydesaffords aryl ketones.r

d\>aoH

t

t

l

\r'\'-H

tl

-.-4

./r

='\rx",.

+(Yo'tr

r(cod)Rhc'2 ayoHlXH

Tffi**Y (83

17)

72Y" cis-l-Alkenylboronates are obtained from the reaction of 1-alkynes with pinacolatoborane and catecholborane, which is catalyzed by [(cod)Rhcl]r-i-pr.,p (Et.N) in cyclohexane.2 A merry-go-round alkylation leading up to four contiguous norbomyl groups in a benzene ring has been achieved.3

Q-*or,,*C## PhMe 100"

Racemization of N-acyl a-atnino acids.a A phosphine is included in the reaction mixture. The mild conditions of the racemization have implications in kinetic resolution as well as low pressure asymmetric hydrogenation at high conversion. Under such conditions, the occurrenceof racemization results in a decreaseof ee. Acylation, Acylation at an a-position of N-(2-pyridyl)amines by a combination of co and an alkene (e.g., ethylene) is conducted with the aid of [(cod)Rhcl]2. The pyridyl substitutentin the substratesis essential.s

Aldolreactions. Reductivealdohz: methyl syn-2-methyl-3-hydroxyalkanoarr consists of [(cod)RhCl]2, Me-Duphos interdependenceof the metal, ligand. and beenwitnessed.

With CO-H2 under pressure, the Rh r and then cyclizationinvolving remotesrlr OSiMe3 'tda

r\

\-V R

;

Methylation.s On promotion br. rh methylation with MeX to afford ArMe.

Kokubo, K., Matsumasa,K., Nishinaka.y. Itrr rOhmura, T., Yamamoto,y., Miyaura, N. ./ACS I 'Oguma, K., Miura, M., Satoh, T., Nomura. Il . 'Hateley, M.J., Schichl,D.A., Kreuzfeld.H.-J . I 'Chatani, N., Asaumi, T., Ikeda, T, yorimrsu. S r 2000). 'Taylor, S.J., -Hollmann, Morken, J.p. JACS l2l, 122O2rtfF) C., Eilbracht,p. I56, 16g5 (20O, 'Hossain, K.M., Takagi,K. CL l24t (1999t.

BisIchloro(diphenylphosphinobutanc )rt Intramolecular ene reaction r Intern to undergoan intramolecular enereacuonI
9lvo, often 99o/o).ln these processes (such as conjugate addition to alkenylphosphonates2),the use of arylboroxines (ArBO)1 instead of arylboronic acids is advantageousbecause catalytic activity of the Rh complex decimatedby large amount of water can be avoided.

+ PhcHo

,F)

)anagisawa, A., Matsumoto, y., Asakawa, K.. ).ea

2,2'-Bis(diphenytphosphino)-1,1,-binaphthyt 55

-r . .. ,\\tropone extendsthe scopeof this ' .:\ renesto afford N-arylbenzylamines F. ilr:.- .i.tems constitutingother Pd(II) salts rt ^9lVo, often 99Vo).In the use of [\-: : alkenylphosphonates2), catalytic because advantageous Dl, :.:Js is avoided. be water can F 3:'. unt of

(R)-BINAP - AgOTf

+

PhCHO

-----------+

R3SnOMe

/-lA,n (,

M e O H .T H F

(major) Yanagisawa,A., Matsumoto, Y., Asakawa, K., Yamamoto, H. JACS l1l,892

(1999').

-binaphthyl 22'-Bis(di-p-tolylphosphino)-1,1'

2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl + l,l'-Bi-2,2'-naphthol copolymer. Alkylation I hydrogenation.t The dual activity for the transformation of ketoaldehydes by complexes of (diamine)RuCl2 with this copolymer is clearly demonstrated. Alkylation of the formyl group with organozinc reagents (e.g., Et2Zn) followed by hydrogenation of the ketone is readily accomplished. lYu, H.-B.,Hu,

rYanagisawa, A., Kageyama,H.. Sr 38,3701(1999). 2loh, T.-p.,Zhou, J.-R.TL 41. 526 Tin(ll) complexes

Aziridines,t The reacuo aziridinecarboxylic esters.A cq

Q.-S.,Pu,L../ACS122,6500(2000).

rJuhl,K., Hazell, R. G., JorgenscnI 2,2' -Bis(diy-tolylphosphino)- 1,1' -binaphthyl. N, O.Bis(ethoxycarbonyl)hydn

Copper(I) complexes Addition

to N-tosybWimines. Protected ct-amino acids are obtained from the addition to ethyl glyoxylate under the influence of CuPF6-[p-tolyl]BINAP. Indoler and allyltributylstannane2 are typical addends.The c-hydroxyamine precursor of the imine can be used in the reaction with enol silyl ethers,sbut a higher (room) temperature is

Lossen rearrangemcnl, followed by mild basetreaunenl

-ocoot

needed.

R-COOH + Htt'

\ cooEr

NHTs l +

Etooc^oH

OSiMe3 ) +

V'pn

Ar iiot buCloa+

i-o,

NHrso Srn Etooc'

Ar

Reduction. cr,p-Unsaturatedestersaand ketonessare reduced asymmetrically, using poly(methylhydrosiloxane) as the hydrogen source. Conjugate reduction.6 p,B-Disubstitutedo,p-unsaturatedestersundergo asymmetric reduction by polymethylhydrosiloxane in the presenceof t-BuONa and a complex derived from CuCl and a slightly modified (i.e., p{olyl) (.9)-BINAP. rJohannsen, M. CC 2233(1999). 2Fang,X., Johannsen, M., Yao,S., Gathergood, N., Hazell,R. G., Jorgensen,K. A. JOC U,4844 (l999). 3Ferraris, D., Dudding,T.,Young,8., Drury,WJ., Leckta,T. JOC 9,2168 (1999). aApella,D.H., Moritani,Y., Shintani,R., Feneira,8.M., Buchwald,S.L.JACS121,9473(1999). sMoritani,Y.,Apella,D.H., Jurkauskas, V., Buchwald,S.L.JACS122,6797(20W). 6Appella,D.H., Moritani,Y., Shintani,R., Ferreira,8.M., Buchwald,S.L.JACS121,9473(1999). Silver(I) complexes Allylation, Allyltrimethoxysilanes are useful donorsr and the reaction of aldehydes with allylstannanescan be carried out in an aqueousmedium.2

rAnilkumar,

R., Chandrasekhar.S.. S

Bis(ethylenedichloro)platin.m Ring opening. 1,2_Cyclo alcoholsin thepresence of theh rBeyer,J., Madsen,R../ACS l2(). l2l

Bis(iodozincio)methane. 1,2-Cyclopropanedials. Cq a-diketonesaffordsthe vic-diolsd R

R

'

+ o'X 'o

Enol ethers.3 The title cor methylenation of estersusing TrCl. Conjugate addition,a Addio the presenceof MerSiCl leads to r chainelongation.

iii

i

Bis(iodozlnclo)methane

+ l.l' -Bi-22''naphthol copolymer' g!:r ::\ for the transformation of ketoalde6 . :..polvmer is clearly demonstrated' by 8... :.'agents (e.g.' EtzZn) followed

rYanagisawa, Y., Asakawa,K., Matsumoto,Y.,Yamamoto,H. ACIEE A., Kageyama,H., Nakatsuka, 38,3701(1999). 2loh, T.-P.,Zhou,J.-R.TL 4L, 5261(2O0O). Tin(II) complexes Aziridines,) The reaction of a-imino esters with diazoalkanes provides aziridinecarboxylic esters.A copper(I) complex can also be used.

ttr.J

'Juhl,K., Hazell,R. G., Jorgensen, K. A. JCS(Pl)2293(1999).

the | :t-emtno acids are obtainedfrom and Indoler rc ..: CuPF6-[p-tolyl]BINAP' the imine of precursor cr-rr,Jroxyamine 3 is hc:-. hut a higher (room) temperature

N, O-Bis(ethoxycarbonyl)hydroxylamine. Lossen rearrangement.t Condensation of a carboxylic acid with this reagent followed by mild basetreatment leads to primary amines with one less carbon.

.,OCOOEI +Dcc R-COOH+HN'

'cooet

'Ar

)-:

F

cucloa -

"-o,

NHTso

,rooaS'n

o tl R

N-O.. | tsO

Et3N / H2o +R-NH2

o4-ci

rAnilkumar, M.TL4l,5291 (2000). S.,Sridhar, R.,Chandrasekhar,

Bis(ethylenedichloro)platinum. Ring opening. I,2-Cyclopropano sugarsafford 2-alkyl glycosides on reaction with alcohols in the presenceof the Pt complex. rBeyer,J.,Madsen,R. JACS120,12137(1998).

using |\e:"ner: are reducedasymmetrically' Itl.

r'

rl cr.i-unsaturatedestersundergo asymmetnc prt-.nce of t-BuONa and a complex derived lr .r,BD{AP.

Bis(iodozincio)methane. 1,2-Cyclopropanediols. Consecutive nucleophilic addition of the reagentr to a-diketones affords the vic-diols that can be trapped with Ac2O and MerSiCl.2

R \

, K' A' JOC U' 4844 i ii:rcll. R. G., Jorgensen IOC 9,2168 (1999)' lr(1999)' E \1 Buchwald,S.L.JACS121,94'13 (20[0)' i 122,6797 /ACS L rIJ S.L.JACSl2l'9473 (1999)' , F.rt Buchwald,

u. R in bulkiness

Matsumura,R., Suzuki,T., Sato,K., Ob {1, 7701(2000).

Bis (2,2,2-tnfluoroethyl)acytmetbylpl

Functionalized alkcnes. (ZyF, nates by the Emmons-Wadsworth ree preparedfrom the cr-bromo-c_phosph

o

rltami,K., Nokami,T.Yoshida, I. OL2, 1299(200CD.

)'Bis(2-tosyloxyethyl)diphenylsilane. Protection of amines.t Reagent I is prepared from diphenyldichlorosilane by the following sequence: reaction with vinylmagnesium bromide, hydroboration of the resulting divinylsilane, and tosylation. The 4-diphenylsilapiperidines that are formed with primary amines can be cleaved by exposureto Csfl BurNF in THF or DMF.

????? r-c Pr.-o o-\ CFr

Yu,W.,Su,M., Jin,J. TL 40,6725,l999t Tago,K., Kogen,H. OL2, 1975e(J/J[t.

3,3-Bis(2,2,2-trifluoroethyl)phosphonates

E{|l lborate. 'D::. - .{lder reaction of Danishefsky's It:.. rr-ntum complex. The adductsare

Ph,r-r Si Ph'\-

6l

/OTs \

OTs

(r) h:-':. .pcciesfrom this reagentcan be kcr:irr of the C-S bond(s).r

c\

3H -R'

'R'

-\Z\

R' I

n'

rKim, B.M., Cho,J.H.TL 40, 5333(t999).

Bis(tributyltin) oxide. 13,4142;15, 39; 18, 54; 19, 4O;20,50 Oxepanes't 2-(ct-Hydroxyalkyl)oxepanes areobtainedby an intramolecularsubstitution of 6,7-epoxyalcohols.An epoxidethat is part of a glycidyl ethersystemreactsby mediationof (Bu.sn)2o.The corresponding glycidyl estersaffordrelatedproductsin low yields.

(Bu3Sn)2O / PhMe; + Eu(OT03

&:'.:t:.r lrilyl)methane,is availablefrom f ::. :.'sulting 2-PYMe2SiCH2Liwith lr.< ^:th BuLi in ether and treatment l g ' . . :r r e l d s . l

.4t !,-

x tl

\A",'\',R' ,/\

| I

R

r} -€ss

'Matsumura, R., Suzuki, T., Sato, K., Oku, K., Hagiwara, H., Hoshi, T., Ando, M., Kamat, Vp. TL

4r,7701(2000).

Bis(2,2,2-trifluoroethyl)acylmethylphosphonates. Functionalizedalkcnes. (Z)-Enonesare accessiblefrom the acytmethylphosphonatesby the Emmons-wadsworth reaction.rsimilarly, (E)-a-bromoacrylates havebeen prepared from thec-bromo-ct-phosphonoacetate esters.2

O tl

(

,,\-f'-"

/-cFs

o-1 CFs

r.J :r,,m diphenyldichlorosilaneby the r..-::: bromide, hYdroboration of the that are formed with p3:.,..:lapiperidines f

b.;-\F in THF or DMF.

\u. W.,Su,M., Jin,J. TL40,6725(1999). Tago,K., Kogen,H. OL2, 1975(20N).

(Me35i)2NK

o ,\:

Ph

95o/o (all Z-)

ds-2,3-Bis(trimethylsilyl)cyclopropanone

2-Bis(trifl uoromethylsulfonyl)amino-s-chloropyridine. Triflation,t The stereochemical outcome in the O-triflation of p-keto esters (K salts) with this reagent is solvent dependent:(E)-selective in THF, (Z)-selective in DMF. lShao,Y., Eummer,J.T.,Gibbs,R.A. Ol, 62'7(199r. \

2,2' -Bis(2-trimethylsilylethoxyrnethor.vF 2- (TrimethyIsily I) ethory methylation_: towardsilyl enolethersin thepresence of S

o+

N, O-Bis(trimethylsilyl)acetamide. Proton acceptor.t In the displacement reaction of allyl carbonates with nitroalkanes,the presenceof this silylated acetamideaffords good diastereoselectivity.

co

. NSiMe3

t/'(

OSiMe3

+

OCOOMe

(

l

Noz

cH2ct2

Noz

I Ishihara, K., Nakamura, H., yamamoto, H..lr{C!

85Yo Methyl p-nitrosoacryIate.2 Methyl 3-nitropropionate is partially deoxygenatedby N,O-bis(trimethylsilyl)acetamide. In the presence of a cyclic conjugated diene the conjugated nitroso compound is trapped as a Diels-Alder adduct.

.NSiMe3

or*),

OSiMe3

\cooM"

o*a""""" c'lua.""""l

Nucleotide phosphates.3 Nucleoride phosphatesin dichloromethane by bis(tnrn bis(trimethylsilyl)acetamide and a catalyuc :

X = CHz 57% X = CHzCHz 21%

rTrost,B.M., Surivet,J.-P.JACS122,6291(2000). 2Tishkov, A.A., Lyapkalo,I.M., Ioffe, S.L.,Strelenko, Y.A.,Tartakovsky, V.A. OL2, 1323(2000). cis-J 3-Bis(trimethylsilyl)cyclopropanone. Furans.t The reaction of this reagent with cr-ketomethylenephosphoranesunexpectedly affords furans.

t".t'^,_

ro

Me3Si

ph3p:

Bis(trimethylsilyl) peroxide. 20, 5 I Nef reaction.t Nitronate ions are orrd Addition to double bond.2 Alkenes r acetoxy alcohols on reaction with Me,SiX promotionby a Lewis acic.

Me3Si]-

uesilo\n R = Me 70%

'Takanami, T., Ogawa, A., Suda, K. TL 41, 3399 (2N0).

Shahi,S.P.,Vankar, Y.D.SC 29,4321(tc)ggt. -Sakurada, I., yamasaki, S.,G R,N\',,NM",

Br-

.r.tlnt\.t'

r)

rc hldrolysis on exposureto . ,'r hariumhydroxide)prevents

Delarue, S.,Sergherart, C. TL 40,5497.lggg).

ld

x: !:.

.: .rr C--3 with bromine. Treat:ntothe isatins.

, -N

t 1,3-Butadien-1-yl)dimethylsulfonium tetrafluoroborate. Alkenyl epoxides.r A three-componentcondensation reactioninvorvesan anion, an eldehyde,and the dienylsulfoniumsalt.

o F

R

^,-cHo

+

4\y'\t'. BF

y I

+

Etooc --vcooEt . Na*

| NHAc

-.-:: cnrcr, -40-23

cooEr Ph-T>-'\-"\Lcbdet Ot

I NHAc

90%

Rowbottom, M.W, Mathews, N., Gallagher, f. JCS(Pt) 3g2:.(lgg8t. L

Ct(

irrr ".",ut ru, on with triethyl .'hrdes. although formation of shcn 1,3-propanediolis present

r2,3-Butadien-1-yt)tributylstannane. Preparation.t A simple route to this reagentis by reactionof 1,4-dichroro-2_butyne "i ith Bu,Snli. Note that coupling of 1,3-butadien-2-ylmagnesium chloride with ph.sncl lcadsto the triphenyl analoguebut the coupling with BujSnCl proceedswithout skeletal . hanse.

1-t-Butoxycarbonyl-I -tosylhydrazine

2-f-Butoxycarbonyl-3-trichloromethyloxazir Hydroxylamines.t Various alcohols an

BuzsnV Bu3sncr

with this reagentafterdeprotonation.

\

ctus-Vt

\-t

I

rFoot,O.F.,Knight,D.W.cc 975(2000).

-

|

tn"n\^

,n.snct,

l-Butyl azidoacetate. The cr a-Azido-phydroxyalkanoates.t useful for the preparationof serinehomologu

t/\

re1,3-Butadien-2-ylation.t The nucleophilic site of the allenylmethylstannane with agent is the central carbon atom of the allene moiety. Its reaction [Ti(IV)-catalyzedl diene unit' aldehydesand acetalsaffords products possessinga conjugated

2:".n CHO f + ,z-1 I ll

rLuo.M.. Iwabuchi,Y., Hatakeyama, S. CC 267(1999)' N-f -Butoxycarbonyl-O'(2-pyridylsulfonyt)hydroxylamine' reaction of p-dicarbonyl Cafiamoylatio,n,t Hydroxamic esterscan be synthesizedvia compoundswith reagent1, which is readily obtained'

r

o

f

^

a synthesisof t-butyl indole-2-carboxylate.

\

\.,'

N3

o-\-

o1{"+

>["4il-",+''' Nl..\lurel S..Mitsuhashi. Kondo,K., Morohoshi,

(1) rHanessian,S., Johnstone,S- JOC 64,5896 (1999)'

-tosylhydrazine. 1-l-Butoxycarbonyl-1 carbonyl compoundsundergoreductivecondensation hydrazines.t substituted by selective from 1,2-di-t-Boc-l-tosylhydtazine prepared is which with this reagenr, hydrogenolysis.

Tt N-NH2

o
< l-BuOOH in the presence Allyl alkyl ethers are converted to ketoness on reaction with This oxidation temperaturc. room at of a catalytic amount of cro.1 in dichloromethane does not affcct THP, TBS, and MOM ethers' alkenes by Pd(oAc): is Arylation of alkcnes.(, Coupling reaction of arenes with reoxidant. Note, this is as a carried out in the presencc ol' benzoquinone ancl l-BuooH

,-N a'

lDumestre,P, El Kaim, L., Gregoire.A. ('C'--:

l

n o t a H c c k r e a c t i o n ( i n v o l v i n g A r H i n s t e a do f A r X ) ' r G u r u n a t hS. . , S u d a l a iA , . Sa 559( 1999). r P e s i r i ,D . R . , M o r i t a ,D . K . , W a l k e r T , . , T u m a s , W 'O M 1 8 ' 4 9 1 6 ( 1 9 9 9 ) ' r L e a d b e a t eN r ,. E . ,S c o t t 'K . A . J O C 6 5 ' 4 7 7 0 ( 2 0 0 0 ) ' r F a s s l e rJ, . , E n e v ,V . , B i e n z 'S . H C A 8 2 ' 5 6 1 ( 1 9 9 9 ) ' 5Chandrasekhar, T 5'L 1063(1999)' S.' Mohanty, P.K, Ramachander, r ' J i aC , . , L u , W . , K i t a m u r aT Y O L l , 2 O 9l ('1999)' F u j i w a r a , . ' ,

Butyllithium. 13,56; 14,63-68; 15, 59 61 . Various usesof BuLi lor & Lithiation. reactwith aldiminesto provide precursor\(tf

l'uransare readily preparedvia alkylation ,.i i Allenamidesare functionalizedat thc o-p tion. Thus, on introductionof an alkynl I cha rcaction can be prepared.3Lithiation oi ihe O -C transsilylation.{5 cngenders

13,55;18,14:19,54 /-Butylhypochlorite. Nitrosoarenes.N.Arylhydroxylaminesundergooxidation(5examples,88-92Vo).

P-

(1999)' rDavey, M.H.,Lee,V.Y, Miller,R.D.,Marks,TJ IOC 64' 4916

polymer 2.1-Butylimino-2-diethylamino-3.methyIperhydro-l,3,2.diazaphosphorine, bound. N.Acylation.|Thepolymer-supportedbaseladequatelyservesforuseinthe acylationof weakly nucleophilicamines'

oAN)

f-l oANAR

u".l: f_A.

-;-

\-^ " \

|

llll R'

Butvllithium t : irr/aphosphorine, polymerbound

>.

I I __.{-\_ \ru' \--l )*-r,-*

t. :rl

-'rrlic acidsrin moderateyieldsby ..,rrlr zed epoxidationof unsaturated .,,und cobalt-phosphinecomplex is

r |A

\--r*(1)

;.rn.lirrmed into ct-silyl-p-hydroxy lKim, K., Le. K. SL 1957(1999).

o o H

l-Butyl isocyanide. Reaction with nitro compound.s.l Homologation to afford ct-oximino amide derivatives is observed.

7'i---""' .retr()nwith t-BuOOH in the presence temperaturc This oxidation .rt r(x)111 ts : .rrcncswith alkenesby Pd(OAc)2 is this Note' reoxidant' a UuOOH as

it r r . : \

'lr

r,rl6(1999).

l l

('i I 199(l)'

r _

r(. j

.

r,)(lI.

rDumestre,P, El Kaim, L., Gregoire,A. CC 715 (1999)'

'74-'l'7; L9,54-59',20,62-65 Butyllithium. 13, 56; 14, 63-68; 15, 59-61'.17,59-60; 18, that subsequently ethers include deprotonation for Bul-i of Lithiation. Varioususes tetrahydro2-Alkylidene pyffolidin-3-ones.r of precursors rcact with aldiminesto provide 2-sulfonylmethylenetetrahydrofuran.r of furansare reaclilypreparedvia alkylation lithiaAllenamidesare lunctionalizedat the ct-positionby virtue of thc regioselective Pauson-Khand the of precursors valuable chain, tion. Thus, on introductionof an alkynyl or allenyl alcohols reactioncan be prepared.rLithiation of the silyl ethersof propargyl * C transsilylation.r' c n q e n d e rOs

,.:r,) o\idation(5 examples'88-927o)' h.l. lei6

Pr

( 1999).

polymer lpt rhr dro- 1.3.2-diazaphosphorine' t-

63%

in the ..r I eticquately serves for use

P-r

o4uAR Pf oA*

(-. -\\

BuL: -^--\. R ;* I

lll I

R'

"--

oAr.rAR N,4o(CO)6

.,\'-^

t

q

t

F

o

Butvllithium

il

v. -:i


oHc..,/\ i l l \z\NN/e,

]:Y-fi / r)-

"

\Z\Nvr",

/

MeO

-

\

/

oEt + Bu-Lt OEt

81Yo

of the silyl enol The above revefse tlrook rearrangementalso occurs during treatment gives an PhcHo with with BuLi. Quenchingthe enolate ether of o-bromoacetophenone aldol product.6 createsa new nng' Halogen-lithium exchangefollowed by intramolecular substitution presence of two The Such a method is the basis of a benzodihydrofuran synthesis. exchangeablehalogenatoms(2,6-disubstitutionpattern)makesitpossibletointroduce al C-7.7 anotherfunctionalitY

The halogen-lithium exchange of regioselectivityin ether and toluene.r: N-Acylntion.ts Primary arylamirrs subsequentexposureto an ester at lo$ tem Wittig reanangements.tt Solvent e ment of benzYl ProPargYlethers.

'b""-

BuLi/ THF

fi{osivreo VBr

7 4o/o

Br B u L i/ T H F

)'-.-.o",

t

i

\,"\Br

l

l

\Br

HCONMe2

oYo Et2O , O" EtzO-THF - hexane -110' 62%

f1^

lYt i l

V\cHo 76Yo

by Sn-Li exchangeand O,Cs-Dilithio enolatesare generatedfrom p-stannyl ketones enolization.n Alkenes'(Phenylsulfinylmethyl)diphenylphosphineoxideisreadilydeprotonated sulfoxides.' for condensarionwith aldehydes,affording (8)-alkenyl phenyl by elimination of terminated is olefination Julia-Lythgoe of the A sulfoxide version r') vicinal hydroxyl and phenylsulfinylgroupson treatmentwith BuLi Solventdependence,solventdependenceoftheproductsarisingfromeither with BuLi has been isomerizationor elimination of propargylic acetalsrron treatment witnessed.

rAmombo, M.O., Hausherr,A., Reissig.H -L' 2Edwards,G.L., Sinclair,D.J.TL&' 39-1-rt l9 rxiong, H., Hsung,R.P, Wei, L.-L', Beq. CJ aSakaguchi,K., Fujita, M', Suzuki,H.. Htges sstergiades,LA., Tius, M'A. JOC 64"15t '1rl' 6Comanita.B.M., Woo, S., Fallis' A.C. fL a. TPlotkin,M., Chen, S., Spoors'P.G.IL 41. 8Ryu, I., Nakahira, H., Ikebe, M., Sonoda \ . evanSteenis,J.H., van Es, J.J.G.S.'van dcr G roSatoh.T.. Hanaki, N', Yamada,N., Asarrc. T rrLe Strat,F., Maddaluno,J.TL4l' 5367 tlffi r2Wang,X., Rabbat,P.,O'Shea,P.,Ttllyer. R . rrooi, T., Tayama,E., Yamada' M.' Mantob I raTomooka,K., Harada, M., Hanji' T.. Natar. 1

,.j

Butyllithium

Eto. -oEt

Et2O

/

NMe2 MeO

81%

oEt + Bu-Li

_-lr;-

OEt

I

f,.-

1l:

It r.

- Juring treatmentof the silyl enol rhc cnolatewith PhCHO gives an s n e wr i n g . . . . r r . u h s t i l u t i ocnr e a t e a ': .rnthesis.The Presenceof two ::r , makes it possible to introduce

/oEt

ttt- 40.

)

/:c--/

MeO

I

F.C=C-J MeO

The halogen-lithium exchange of 2,5-dibromopyridine also shows different regioselectivity in ether and toluene.12 N-Acylation.t3 Primary arylamines form amides on dilithiation with BuLi and subsequentexposureto an ester at low temperature. Wittig rearrangements.t4 Solvent effects dominate the mode of Wittig realrangement of benzyl propargyl ethers.

o o H

r l l

-_.r^\-

I

pn

'4siM".

"bfu *G(."".fl.o.--q

74lo

0% E t 2 o ,o ' Et2O-THF- hexane - 110" 62%o

55Yo

14To

4%

8Yo

Yr l

\-^cHo 76%

:i I kctonesbY Sn-Li exchangeand rl: l- ..

l: f,_-

t

rLnc oxide is readily deprotonated . phcnylsultoxides." r,,n is terminatedby elimination of ' n ts i t h B u L i . r 0 rhc products arising from either \rn treatmentwith BuLi has been

rAmombo, M.O., Haushen,A., Reissig,H.-U. SL 1871 (1999). r Edwards.G.L.. Sinclair,D.J. TL 40, 3933 ( 1999). 'Xiong, H., Hsung,R.P.,Wei, L.-L., Berry, C.R., Mulder, J.A., Stockwell,B. OL2,2869 (2OO0). lsakaguchi, K., Fujita, M., Suzuki, H., Higashino, M., Ohfune, Y TL 4l' 6589 (2000). 5Stergiades, 1.A.,Tius, M.A. JOC 64,'154'1(1999). nComanita,B.M., Woo, S., Fallis,A.G. TL 40, 5283 (1999)' -Plotkin, M., Chen, S., Spoors,P.G.TL 41,2269 (2000)' rRyu, 1., Nakahira, H., Ikebe, M., Sonoda,N., Yamato, S., Komatsu, M. ./ACS 122' l2l9 (2000). 'van Steenis,J.H., van Es, J.J.G.S.,van der Gen, A. EJOC 2781 (2000). rSatoh,T., Hanaki, N., Yamada, N., Asano, T. T 56,6223 (2000). rLe Strat.F.. Maddaluno,J.TL41,536'7 (2000). rWang,X., Rabbat,P.,O'Shea,P, Tillyer, R., Grabowski,E.J.J.,Reider,PJ. TL 41,4335 (2000). 'Ooi, T., Tayama, E., Yamada, M., Maruoka, K. SL'129 (1999)' 'Tomooka, K., Harada, M., Hanli, T., Nakai, T. CL 1394 (2000)'

TMEDA

Butvllithium-N,N,N'N"tetramethylethylenediamine'

LI

Butyllithium-2-(N,N-dimethylamino)ethanol' Lithiationofpyrid'ines.3-MethylpyridineisregioselectivelylithiatedatC-6with thisbasesystem,lwhichismarkedlydifferentfromitsbehaviortowardLDA(benzylic lithiation,).2-Chloropyridinebehavessimilarly'2

,*k 7\-6

N--w

Buli - TMEDA EtzO - 100'

rMathieu, J.,Gros,P, Fort,Y'CC951(2000)' rChoppin,S.,Gros,P.'Fort,Y'OL2,8O3(2000)'

a

\1

Butyllithium-potassium r-butoxide' Cyclization.lFusedl-vinylcyclopropanesareformedonlithiationofallylsulfides that bear an alkenyl chain at the ct-position'

/ (

SPh

-\Z\

CeH

BuL.,.BuoK -rHF CA l+ L-lX'"'*,'l

a- K",r,, 81Yo

Lithiation.rn-Methoxybenzoicacidand3,5-dimethoxybenzoicacidarelithiatedat c-4.2 rCheng,D., Knox, K.R., Cohen,T' JACSl22' 412 (2000)' S TL 41' 3 157 (2000)' 2Sinha.S., Mandal, B., Chandrasekaran,

|

17-i 9' ll s-Butyllithium . 14, 69; 16, 56; 18, Lithiation of aromatic compounds' H are lithiated at the ortho position'' Indole-2-carboxylic esters'1 Benzlhc mates followed by addition of alkyl oralatc treafl indole-2-carboxylicestersynthesison

l-l L-o * co2 + R2NH 40atm I 2,4-Dihydroxyquinazolinesare obtained when 2-cyanoanilinesare treatedwith CO2 of an aminesuchas DBU.7 in the presence

rcagentsconvenientlyintroducesan

o lt R-')r N

OH CN NHz

'il-\_/-

R=Ph

/:\

96%

ZtA* DBU / Dl\'lF

\.{*Ao,,

Reaction medium. By virtue of its attributes supercritical carbon dioxide deserves its increasing applications as a reaction medium in synthesis.These include epoxidationn with oxygen and PhcHo, rhodium-catalyzed hydroboration,' Pd(0)-catalyzed 1,4' I hydroarylation of enonesr{)and Heck reaction in the presenceof Pd-C,r cafbonylation of aryl halides,r2Glaser coupling of l-alkynes (mediated by cuCl) using a solid base (NaOAc),rr as well as scandium(IID perfluorooctanesulfonate-catalyzedDiels-Alder and Ia hetero-Diels-Alder reactions.

(1998). r c. r54,5315

Cartronlldh

Carbon disulfide

Investigations have shown that in Pd-catalyzedreactions in supercritical carbon dioxide, superior results are obtained with catalysts containing fluorinated ligands [e.g., (CFTCOO)rPdand (F6-acac)Pd vs. their respectivehydrogenanaloguesl.rs Continuous, selective hydroformylation in supercritical CO2 using (acac)Rh(CO)2immobilized on silica as catalyst'o shows certain advantages.A version of asymmetric hy(SubcriticalCO, gas accelerates droformylationin this medium has also beenreported,.rT solventlesssynthesis involving solid reactants,r8including hydrogenationand hydroformylation.) The regioselective and enantioselectivenickel-catalyzed hydrovinylation of styrenesin supercritical CO, make 3-arylpropenesavailable in an optically active form.re Improvement in the performance of the Pauson-Khand reaction in supercritical media is due to thorough dispersion of catalytic metal species.Besides CO2,20supercritical ethylene has the sameeffect.2r Water and supercritical carbon dioxide form an excellent medium for hydrogenation of unsaturated aldehydes to allylic alcohols with ruthenium(Ill) chloride and a waterbecausethe limitation pertaining to gas-liquid-liquid mass soluble triarylphosphine,22 transfer is eliminated due to the very high solubility of reactantgas. IKadokawa, (1999). S.,Karasu,M., Tagaya, H., Chiba,K. JCS(P1)2205 J.,Habu,H., Fukamachi, 2Kim,S.-L,Chu,F.,Dueno,E.E.,Jung,K.w. JOC 64,45'18 (1999). rYamaguchi, K., Ebitani,K., Yoshida, T.,Yoshida, H., Kaneda, K. JACSl2l,4526 (1999). rSakakura, T. JOC 64,4506(1999). T., Choi,J.-C.,Saito,Y,Masuda, T., Sako,T., Oriyama, 5Casadei, M.A., Moracci,F.M.,Zappia,G., Inesi,A., Rossi,L. JOC 62,6757(1997). ('Ishii,S.,Zhou,M., Yoshida, Y.,Noguchi,H. SC29,3207(1999). TMizuno, T., Okamoto, N., Ito,T.,Miyata,T. rL 41, 1051(2000). n|-oeker. F..Leitner.W. CEJ6.201I (2000). eCarter, C.A.G.,Baker,R.T.,Nolan,S.P.,Tumas,W. CC 341(2000). '"Cacchi,S.,Fabrizi,G.,Gasparrini, I'-.,Pace,P, Villani,C. SL650(2000). rrCacchi, F.,Villani,C. Sa 345( 1999). S.,Fabrizi,G.,Gasparrini, l2Kayaki, Y.,Noguchi,Y.,lwasa,S.,Ikariya,T., Noyori,R. CC 1235(1999). rr|-i,J.,Jiang,H. CC 2369(1999). raMatsuo, J.,Tsuchiya, T.,Odashima, K., Kobayashi, S. Cf 178(2000). rsShezad, N., Oakes,R.S.,Clifford,A.A., Rayner, C.M.TL 40,222'l(1999). '"Meehan, A.J.,Reek,J.N.H.,Kamer,PC.J.,van Leeuwen,PW.N.M.,Poliakoff,M. N.J.,Sandee, cc t497 (2000). rTFrancio, G.,Leitner,W. CC 1663(1999). rEJessop, D. CC 693(2000). P, Wynne,D.C.,DeHaai,S.,Nakawatase, 'eWegner; A., LeitnetW. CC I 583( 1999). 2{)Jeong, N., Hwang,S.H.,Lee,Y.W.,Lim, J.S.JACSll9,10549 (1997). rrJeong, N., Hwang,S.H.ACIEE39,636(2000). ?rBhanage, B.M.,Ikushima, Y, Shirai,M., Arai,M. CC 1277(1999). Carbon disulfide. 1,3-Dithincycles.t 1,3-Dithianesand 1,3-dithiepanes are formed from 1,3- and 1,4dihalideson reactionwith CSr and NaBH4. Isothiocyanates.z Sequential treatment of organic azides with PhrP and CS2 gives isothiocyantes.This processcan be applied to a synthesisof isocyanatoalkylphosphonates.

rWan,Y, Kurchan, L.A., Kutatela A.N.,Bamhurst, rSikora,D., Gajda,T. Pss 157,201(2000). Carbon monoxide.20, 72 Diaryl diketones.t Highly hindered anl CO to provide the 1,2-diketones. lNudelman, 422(1999t. N., Schulz,H. "|CR(S) lf Carbonyl(chloro)hydridotris(tricyclohexl The Ru complex is a h HydrogenationI of alkenes.2 Terminal alkerr Silylation reagentsand the Ru complex as catalyst. Dehalogenation,s Haloarenes are redn: that can be generatedin situ from [(codtRuCl'

lyi, C.S.,Lee,D.W. OM 18,5152(19991. rYi,C.S.,He,Z.,Lee,D.W, Rheingold, A.L..Lam. rCucullu,M.E.,Nolan,S.P,Beldenain, T.R..Gnrhh

Carbonyl(chloro)hydridotris(triphen-r-lphoq Double-bonil migration.t Deconjugatrt

SnBu3

(Ph:P.Q:

Bu3Sn/\-.\..CooMe

(Ph.P

Qr

Bno*cooMe Silyl group transfer.2'r Allylsilanes an! alkenessuch as styrenesand vinyl ethers.lt r.

ErO'\

+

siMe3

>i

\

'Wakamatsu, H.. Nishida,M., Adachi,N.. \lon. \l rKakiuchi,F.,Yamada, A., Chatani, N.. Murar.S . F 'Marciniec, B., Kujawa,M., Pietraszuk, C. O.rt19.l

Carbonyldihydridotris(triphenylphosphiac t Addition reactions.t'2 Electron-dc-ticr ketones, add to unsaturatedsilanes in thc p extensionoccursat the ortho Dositionof thc C

Carbonyldihydridotris(triphenylphosphine)ruthenium(II)

-.1!tronsin supercriticalcarbon diox, ,ntaining fluorinated ligands [e.g.'

lr a. f' l . Ia t i -

lr & F*-h._

t' s .

. .lrogcnanalogues].1s '-:rtrcalCO2using(acac)Rh(CO)2 imA version of asymmetrichy.,]rrretlS. '-'J. - tSubcriticalCO2 gas accelerates .ncluding hydrogenationand hydro. j nickel-catalyzedhydrovinylationof .,. .rrlablein an optically activeform.re Khund reactionin supercriticalmedia - - rc.. BesidesCO2,20supercriticaleth,. .\ccllent medium for hydrogenation :uthcnium(Ill) chloride and a waterpcnaining to gas-liquid-liquid mass

ni.: rl-^ r, i)l reactantgas.

(d r l

s..

: : . , \ r . H . . C h i b a ,K . J C S ( P I ) 2 2 0 5 ( 1 9 9 9 ) ' :9

%o"'Y

(30)

^, n center are obtained from . ^rnz1I alcohol. One such Prod-

tt/.-

/

i-PrOOC,.. " n

('"' I B )-: (J

/

Ph

-J

J

i-ProoCT

(38)

(37)

I

3

':r('r \how cooperativereactivity . :-c()nlplex33 is the optimalcat-

I

:.'. ()n reactionwith Me.SiNq.s8b

The chiral sulfoxide 39 is valuablefor assemblageof 1-butenolideson lithiation and The 1-selectivealkylation of 40 with reaction with aldehydes(low ee with ketones).6E use.6e aldehydeshas certain synthetic such as 41 are useful assemblingplatforms that allows 1,1-Bis(borylmethyl)ethylenes Diastereoselectivityand enantioselectivityare 1,5-diols.T0 bidirectional synthesis of usuallyhigh.

,-/

'N"

H

,

(33) h. l:.

\ ',dt X-,:'1 0

.:lcloped fbr the PreParationof , .r stcrlSincludingvanadyl-salen : rlrc3{-titanaten:areeffective.

-)-

-)-o

v

9r|i-)

-,rr"d N

)

( OTBS

/(3e)

/

(40)

Chiral auxiliaries and catalysts

Phosphoramideligands represe lation and aldol reaction. Their prq Aldol reactionwith l-proline as eratinganri-diols.3s Transitionstar

@t'-l'Td (41\

A direct synthesisof chiral propargylic alcohols from l-alkynes and aldehydesin the presenceof Zn(OTf)2, Et3N, and (+)-N-methylephedrinehas a broad scope.TrSeveral new ligands are found suitable for inducing asymmetric addition of R2Zn (mostly diethylzinc) to aldehydes.These include 42,1243,1344,1445,7sand 46.16Other B-amino which is more alcohols that show desirable features are 3-exo-morpholinoisoborneol,TT stable in air than the dimethylamino analogue, (S)-2-(pynolidin-1-y1)-1,z,2-trtphenylethanol,T8 and a polymer-supported N-alkyl-o,ct-diphenyl-l-prolinols.Te N,N-Dibutylnorephedrineis useful in a solvent-free reaction.80

!-< \/-NH

ri. ,'N=

r.P< l l

|

\

\Ap-r l ) a--J

(e3)

/

(e4)

r

)-een2

\-rrn, '

(e5)

PPh2

(-z< [""n'**"

(e6)

116

Chiralauxiliariesandcatalysts

carAmong the effective diphosphine-Ru-diamine complexes used for catalyzing atoms phosphorus the in which member one is enantioselectively bonyl hydrogenation re7 are attachedto a l2,2lpatacyclophaneunit. in the The principle of asymmetric activation-deactivation has been demonstrated racemic of Ru complex a of consisting system a catalytic using ketones of hydrogenation following dimethyl-BlNAP and two chiral diamines.re8The principle is depicted in the diagram.

(es1 substrate

[ _

trs)-*al @ u_ L=:l ffffffffffffffff/nr-*fl g

_____\ llrst-catl l(s)AJ ----)PRoDUcr

l-

:

,

| | rn;-cat1""'l(n)-oeact I -_)

asym Platinum catalysts modified by cinchona alkaloids have been developed for of complex Ru the and metric hydrogenation of ct-keto acetalsreeand a-keto esters,2O0 chiral 2-(MeO)BIPHEP 97 has been developedfor B-keto sulfone reduction.2Ol p-keto esters Ruthenium-basedasymmetric hydrogenation of ct-arylacrylic acids and

Good resultshave been obtained from h1d of indolesurt cationiczirconocenecatalyst,205 2-(MeO)BIPHEP-Ru a and of 2-pyroneswith Very efficient ligands that complementt' ' are l0l.: droaminoacids(and derivatives) 87 with Rh+ has the versatilityof catalrnne and conjugateaddition.2r'

usesthe bipyridylbisphosphine98 (and its enantiomer)'202

OMe

HO

o MeO

PPh2

MeO

PPh2

MeO

PPh2

MeO

PPh2

(J

Pl

Ph2P.Rh/

(} OMe

(101)

il

(e7)

(cod)zRhBF+ The ferrocenyldiphosphineligand 99 constitutes a catalytic system with Seccompounds'2{)3 alkylidene for synthesizing ct-alkylsuccinic acid derivatives from the using acetates enol of ondary acetatesin chiral form are accessiblefrom hydrogenation the catalytic system of (cod)2tthBF4-100.2s

The paradoxconcerningthe generattonc and,\'-t I -r-l 't N-( l -phenylvinyl)acetamide of sutrsu mode .r()odon the groundsthat the stere(^-iE :hc catalyticcycle determinesthe

Chiral auxiliaries and catalysts

tt7

carF i..-'. used for catalYzing atoms 1- .irruh the PhosPhorus n :..:- heen demonstratedin the lt::' : ,'i a Ru comPlexof racemrc r: . :. dePictedin the following

-

r

L.

I

substrate

PRODUCT

J

)

e a- :

-

,.: heen develoPedfor asYm and the Ru comPlex of c ' :.. '.-.I,tnereduction'2ol u*. ,-:rlic acidsand p-ketoesters

Good results have been obtained from hydrogenationof tetrasubstitutedalkeneswith a ?06 of indoles with a bis(ferrocenylphosphine)-Rhsystem, cationic zirconocenecatalyst,205 and of 2-pyroneswith a 2-(MeO)BIPHEP-Ru complex.2{)7 Very efficient ligands that complement (cod)2Rh+salts for hydrogenationof dehyand 103.2r0A combinationof ligand 102,20') droamino acids (and derivatives)are 101,208 87 with Rh+ has the versatilityof catalyzingasymmetrichydrogenation,hydrosilylation, and conjugateaddition.2rI

OH

----( I

)" oH

a-

a-Y':'.,.--

12 \PPhz

\-\r{

PPh2

I FOH ,.'\\,/ \ : \ b x (101)

-/^ Ho1 Ho"'\ ) " (/-o,

Ho

ro r-.. o o

Ph2d\

\oeen, 6.!",oeen'

-\u

..'PPh2 Rh

/\ ^

NJ\ \--r

(102)

(103)

98

r-:1.,.rttc systemwith (cod)zRhBFr Sec| ::.- .1ik\lidenecompounds.203 uslng acetates i.:: :r'nition ofenol

The paradoxconcerningthe generationof oppositeenantiomersin the hydrogenation of N-(l-phenylvinyl)acetamideand N-(l-t-butylvinyl)acetamidewith 104 is now understoodon the groundsthat the mode of substratcdocking at the migratory insertionstepof the catalyticcycle determinesthe stereochemicaloutcome.2rr

Chiral auxiliaries and catalYsts

f18

\11

H.

NHAc

\ D .

ANH

Y i r' l-'oY1n.^ ;

,i-l

I "

NHAc a Ph/\ 99% ee

rl ,,\J '-;n''' . \o/ "'( ."'' \,1

/

r12

b

\4

S

/

BFA \

Accessto bicyclic enonesfrom 1.6-en1n

cnantioselectiveby installing a chiral t-bu cr-benzylidene-aroylacetamidesto furnish -1

z'J*{' ->-; I ri H.

Yti-ri-,"^*t^' { l''1.,X

,\,

Heterocyclic analoguesof BINAP, such ar -bis(diphenylphosp 2,2',5,5' -tetramethyl-4,4' and testedin the Heck reaction.22rIncorporarx sulfinyl group to a double bond elicits eru intramolecularHeck reaction.222 Opticallr a ides are produced from (R)- 1-t-butylsulfin1lc1 Palladacycle (109) and its analogues ind

rearrangement of allylic imidates.22rFor a thioamides, it is convenient to allylate thr dine.225 This processinvolvesa thio-Claisenn Enantioselectivedeprotonation of ketorrs sium bis[N-benzyl-N-(ct-phenethyl)] amide,: :" tonationof enolates.227

(104)

/

NHAc \,/ I

I

l

/

L >-\

H.

do9in ,.' A \ |/ / t - ->NH

i fi- ),pn4 / " \ \ l

PhA

/

\,/

,)f'^\ I

rnduction when the amide moiety is denrc ,rne.22e Chiral ligands for the Pauson-Khand horane(111) derivedfrom (+)-pulegone is an

99% ee PPh2 Other enantioselectivereactions. Severalasymmetricreactionsworth mcntioning are the cu-catalyzeilallylic oxidationin the prcsenccof l05,r1r l06,r1ror l07rr5with loxiclationof sulfides(/-BuooH Tirvl in the prescnceof a 4,4'-dimer of butyl perbenzoate, the reductiveaminationby chiral t-butylsulfinamidc,rrr B-aromatic3-hydroxyestrane,rr('the with ol'phcnols C-arylation gfyoxylate ene reactionpromotedby Yb(OTf )r andent-73.2tE aryllcad reagcntsundcr the influenceof brucine,rr"and the C-H bond inscrtion by Rh-

PPh2

\/ ro;--

----\L-N'

Pd F"CCOO' \

d

,

P

1. (108)

(1Ull

carbenoids.:lo

MeO

H P h NJ VOH

*4-on H P h (105)

A Y2

rt

H".|_N (^\"" i3

(106)

(107)

Enantioselectivecyclization of carbanrtx -rn lead to cis- or trans-1,2-disubstitured c t'232 ' BuLi-( - )- sparteine.23

Chiral auxiliariesand catalysts

\

H

'

= -.1

a;.-Kn1,Lp[

NHAc +

:

I n l -\---NH

-.,,^\ rtl

/

..

99% ee

119

Heterocyclic analoguesof BINAP, such as the bis(benzothiophene)108 as well as the have been prepared 2,2',5,5'-tetramethyl-4,4'-bis(diphenylphosphino)-3,3'-bithiophene, and testedin the Heck reaction.22rIncorporation of a chiral o-(N,N-dimethylamino)phenylsulfinyl group to a double bond elicits enantioselectivity at the B-carbon during the intramolecular Heck reaction.222Optically active 5-arylcyclopenten-l-yl r-butyl sulfoxides are produced from (R)-1-r-butylsulfinylcyclopentene.223 Palladacycle (109) and its analogues induce chirality of N-allylalkanamides during rearrangement of allylic imidates.22aFor a synthesis of a-branched chiral 4-alkenethioamides, it is convenient to allylate thioamides of (*)-trans-2,5-diphenylpyrrolidine.22sThis processinvolves a thio-Claisen rearrangement. Enantioselectivedeprotonation of ketones is achieved by using a homochiral magneOn the other hand, 110 is excellentfor prosium bis[N-benzyt-N-(ct-phenethyl)]amide.226

BF;

tonationof enolates.227 Access to bicyclic enones from 1,6-enynesby the Pauson-Khand method is rendered enantioselective by installing a chiral f-butylsulfinyl group at C-1.228Cyclization of a-benzylidene-aroylacetamidesto furnish 3-arylindanones is subject to 1,5-asymmetric

lO{

-t'

* -.-Rh

NHAc

--,,l--l

induction when the amide moiety is derived from a bulky 4-substitulted oxazolidin-2one.22eChiral ligands for the Pauson-Khand reaction have also been studied. Phosphineborane(1L1) derivedfrom (+)-pulegone is an example.2r0

S

99% ee SiMer PPh2 u

)l

r l_

nctric rcactionsworth mentioning , , r l 0 5 . r r r1 0 6 , : r o 1 r l 0 7 r r 5w i t h / rn thc prcscnccof a 4,4'-dimcr of the hr chirall-butylsulfinamidc,rrT i' phenols with ol' 7-1.r C'-arylation j rhr-C-H

hond inscrtionbY Rh-

PPh2

(108)

\/ .o>__-+_-'-\{-N' -Y F"ccoo'Pd>r i"

yr--f

R,

t

ll

) - COOR'

\-'l-N H

Pocr,-PhN(cHo)N/e- a)-\ ' Kll ll N / C P B A - T S O H /C H 2 C | ,

-

cooR'

\."-N H

80-90% .rnd the title reagent are good -:

tff)0).

::r'rat€dfrom the title reagenton lrto substituted tetrahydro:.iris tlr. '.'ihle when the traPPingagents B

) l { . . + - t i 7 r 1 5 , 8 6 ;1 6 , 8 0 - 8 3 ;L 7 ' , . .-.c' oxidationsserveto complete :r, -'- tr) nitriles,2and B-aminoesters

OTBS

I /\ Ct't 63% (93%ee)

(e'g'' -78') when Epoxidation.e Alkenes arc epoxidized at low temperatures catalyzcdby (MeCN )aCuPF6. with oso-, Dihydroxylation,l0 The conventionalmethod of alkenedihydroxylation reagent latter the that such modificd becn (NMO) has anclN-mcthylmorpholincN-oxide MCPBA' of equiv l 4 and N-methyhnorpholine is replaccclby substoichiometric T S 1299(2000)' T'' Fukuyarna' r1'okuyama, T.,Amano,A', Yamashita' tl., Kuboyama, J M IA l0' ll45 rDicz.Il.. Fernandcz, E, Pareja'C'' Prieto'A ' Lassaletta' R., Martin-Zamora, ( I 999). 'Davics. C.A.P,Smith'A'D ' Smyth'G'D' ?"A1l' 2437(2000)' S.G.,Smcthulst, rCtrrbin, P.'fL 40,23l9 ( 1999)' C.,Metzner, Fl,Alayrac, 'Ma. D..Xia.C..Tian,H. TL 40'8915( 1999)' "Kotsuki.H.,Arimura,K., Araki,T., Shinohara, T SL462( 1999)' 'Wattenbach, U' SL 303( 1999)' C., Maurer,M., Frauenrath' 'llickman,Z'.,Sturino'C.F-., N ?"L41' 8217(2000)' Lachance, 'Andrus. B.W.fL 41, l0l3 (2000)' M.8.,Poehlein, 'ucrgstad, J -E'JOC64.2s45( 1999)' Biickvall, K.. Piet'J.J.N., chloride' I Chloro(phenylthio)methylene]dimethylammonium reagcnt' this by converted are Alkyl halides.t Primary alcohols unprotected atl'ecting without yields in excellent lMc:N:C(Cl)sPhlcl, to the chlorides obtaincd' \ccondaryhydroxyl groups.In the presenceof BuaNBr' the bromidesare C' TL 4l' 6049(2000)' A., Mioskowski' Gomez,L., Gellibert,F'.,Wagncr, 19,95-96; 20' 108 .v-chlorosuccinimideNcs. 13, 79-80; 15, 86-88; 18' 101-102; induced to decompose are (E)-Bromoalkenes.t (Z)-l-Dialkylbora-l-bromoalkenes N, N-dimethyllbrmamide, by is exerted effect \rcreoselectivelyby NCS. A specialsolvent .rndis superiorto DMSO.

132

Chlorosulfonyl isocyanate

a f-a'\-

o

O=C=N-SO2C|

A 'n-cr

Ph

|

\,{

\7

\/

OMe

P

KoH - Na?so3

o THF - D[,,1F

'/-[

[3 + 2]Cycloaddition. l-Lactams arr particular interest is the formation of a I 1 precursorof peduncularine.

82o/o

Methylthiomethylation.2 The Corey-Kim reagent (NCS-dimethyl sulfide) induces cyclization of tryptamine derivatives while introducing a methylthiomethyl group at C-3. An efficientroute to physostigmineis basedon this process.

MeO

(

,!-o""t

\ '-1N) / / t

H

l

'cooMe i

NHCooMe

MeO 1F

Ncs- N/ezs

_SMe

'

(,, ,>.-f-^.

i - p r , N E t \ - - ( \ ) - C O O M e

'ufN

crrci, n

H

o/

H H boovr" Me.

o NH\O\

C,>l-\ -*t^. M6H

Me

physostigmine

Chlorination.s propanol.

>ie

O=C=N-SO2C|

Anilides and deactivated anilines are chlorinated with NCS*2-

Biaryls,a Homocouplingof ArZnI employs NCS as an oxidant in the presenceof a Pd(0) catalyst.Yields are good. lHoshi,M., Shirakawa, K.TL41,2595(2000). 2Kawahara, M., Nishida,A., Nakagawa, M. OL2,675 (2000). rZanka,A., Kubota,A. Sa 1984(1999). aHossain, K.M.,Shibata, T.,Takagi,K. Sa t 137(2000).

Chlorosulfonyl isocyanate. 13, 80-8 1; 18, 102 N-Allyl carbamates.t Preparation of the carbamates from allyl ethers may incur 1.3-transoosition.

iKim,J.D.,Lee,M.H.,Lee,M.J.,Jung,YH. IL I rlsaka,M., Williard,P.G.,Nakamura,E. 8CS/ 7l 'Roberson, C.W.,Woerpel, K.A. OL2,62l rlffi)

Chloro(triphenylphosphine)gold(I). Hexaalkylditins.' Oxidative dimenza (PhrP)AuCl.

Reductive silylations.: In the presen imines undergoreductive silylation b1 a h1 undertheseconditions.

'lto, H.,Yajima,T.,Tateiwa, J.,Hosomi,A. ft I rlto, H.,Yajima,T.,Tateiwa, J.,Hosomi,A. C(-9€

Chlorotris(triphenylphosphine)rhodiun I Allylic alkylations.t 3 Highly regros nucleophiles (phenolates,sulfonamides. and also possible with the Rh catalyst modrha

seems to play an important role in the dr branched allylic ethers; thus, reaction wirh I the product yields are low The best compru

Chlorotris(triphenylphosphine)rhodium(I)

O=C=N-SO,C|

Ph, y'., v

,OMe

'nn

:

> KOH - Na2SO3

\7

\./

NHCOOMe

(2.7 c"

1)

[3 + 2]Cycloaddition. ^y-Lactams are formed on reaction with allylsilanes.2 Of particular interest is the formation of a bridged ring representative that serves as a precursorof peduncularine.3

82Yo

: '\CS-dimethyl sulfide) induces ., nrc'thylthiomethylgroup at C-3.

Ph COOMe

\

/-\

rsiR3

O=C=N-SO2C|;

HN/\

,nlzt'a:)

oN 62To

!

booH,t"

peduncularine

l l,t,-

\\

..- ^ o \

Kim, J.D.,Lee,M.H.,Lee,M.J.,Jung,yH. fL 41,50:13 (2000). rlsaka,M., Williard,p.G., Nakamura, E. BCSJ72,2115(1ggg). tRoberson, C.W.,Woerpel,K.A. OL 2, 621(2000\.

I

/m \r-r-i-( M ; H

M e

physostigmine

. arc chlorinated with NCS-2g ' .

\

1. an oxidant in the presenceof a

!:- , r:ttcS from allyl ethers may incur

Chloro(triphenylphosphine)gold(I). Hexaalkylditins.t (PhrP)AuCl.

oxidative dimerization of RjSnH (e.g., BujsnH) is mediated by

Reductive silyrations.2 In the presence of (phjp)Aucl and Burp, aldehydes and imines undergo reductive silylation by a hydrosilane (phMe2SiH). Ketones do not react undertheseconditions. rlto,H.,yajima, T.,Tateiwa, J.,Hosomi,A. TL 40,7g07(lggg). rlto,H.,yajima, T.,Tateiwa, J.,Hosomi,A. CC 9S1(2000). Chlorotris(triphenylphosphine)rhodium(I). 19, 96_98; 20, 10g_l 09 Allylic alkylafions.t 3 Highly regioselective alkylation of both hard and soft nucleophiles (phenolates,sulfonamides, and phenylsulfonylacetic esters, respectively) is also possible with the Rh catalyst modified by the added (Meo\p. The countercation seems to play an important role in the displacement with alkali phenolates to afford branchedallylic ethers; thus, reaction with Li salts shows the highest regioselectrvity but the product yields are low The best compromise is to use Na phenolates.

Chlorotris(triptaf 134

Chlomtris(triphenylphosphine)rhodium(I)

'nlo)

'nY\ Ph.

ocooMe. a-)-/

(Ph3P)3RhCi

Y\ Mo'V

.t\t2

-^--J

--L/

(NIeO)3P THF

(97o/o)

M = Li

(11o/o)

Chlorotris(triphenylphosphine)rhodin mt I r Hydroacylation. ct-Cleavageof a phen (after elimination of styrene) to an alkene c

2 0 : 1 1 2 : 1 3 8 : 1

M = Na (97olo) M = K

o"\"'

switulski,B., Stengel, T. ACIEE3S'2426(lv)9t 6WendetP.A.,Dyckman,A.J., Husfeld,C.O.. Kid ( l e9e). TVogels, M.P, Westcc* C.M.,Hayes,P.G.,Shaver,

imine formation of the ketone with 2-amr speciescombines with the alkene and then un

Reformatsky-type reaction.a This procedure involves treatment of the ct-bromo esterswith Et2Zn and the Rh(I) complex. This mild and eflicient reaction is applicable to both inter- and intramolecular versions. Cycloadttitions. Substituted indolines are formed from N-functionalized l-alkynyl amides via a 12 +2 +2lcycloaddition process.5A study on the regioselectivityand stereoselectivityof the [5 + 2]cycloaddition promoted by the Wilkinson catalyst together

rY i

o Ph,/\-A

l

l

\"4n..

* R,\

(Ph3P)3RhC PhMe

.r

with AgOTf has beendelineated.6

||I "'

/--'r\ i l

(PhrP)3RhCl (

+ l l l + N-#I

S

'ru-\Z

Further extension of the method resullr r des and alkenes2and, in the case of an aro Imines of aryl ketones undergo o-alkylation

|

PhMe20'

TJ

TS

91Yo

1'\'/

Addition to vinyl aminopropyl ethers.l Boranes add to the double bond in the antiMarkovnikov sense under the influence of the Rh catalyst. However, intramolecular hydroamination to give tetrahydro-2-methyloxazine occurs in the presence of Pd or Pt complexes.

* nAH

\tR'

"t,

o (Ph3P)3Rhcr

H,Nvo-\

ll \*A

o

* f\-- tr J'-to'\ | to,,-

^\

PY-

H'NYo'\-d-o{

tto.,At l ll + \/

(

v.R'

NBn

1]X

lEvans, P A., Leahy, D.K. "/ACS122,5Ol2 (2000). 2Evans.P A., Robinson,J.E.,Nelson,J.D. .IACSl2l,6'761 (1999). 3Evans,P.A.,Kennedy,LJ. OL2,2213 (2000). lKanai, K., Wakabayashi,H., Honda, T. OL2,2549 (2OOO)-

* \-R' ri,^"1,,^\/

J u n ,C . - H . ,L e e ,H . J A C S1 2 1 ,8 8 0 ( 1 9 9 9 ) . Jun, C.-H., Lee, D.-Y., Lee, H., Hong' J.-8. ACri J u n .C . - H . ,H o n g ,J . - B . ,K i m , Y - H . ' C h u n g .K - l

Chlorotris(triphenylphosphine)rhodium(If 2-Amino-3-picoline

=^-.2-.,

Ph:Z\

,\-.l,J

.

l-z

,^-,,\,

-,

20

,

o^.,,lj

rl-:

5witulski,B., Stengel,T. ACIEE 38,2426(1999). 6Wender, P.A.,Dyckman,A.J., Husfeld,C.O.,Kadereit,D., Love,J.A., Rieck,H. IACS l2l, 10442 (1999). ?Vogels, C.M.,Hayes,P.G.,Shaver, M.P.,Westcott, S.A.CC 51 (2000). Chlorotris(triphenylphosphine)rhodium(I)-2-Amino-3-picoline. Hydroacylation. ct-Cleavageof a phenylethyl ketone and delivery of the acyl group (after elimination of styrene) to an alkene occurs around Rh. The reaction starts from

.. 'l

1 2 : 1 3 8 : 1

trl

imine formation of the ketone with 2-amino-3-picoline. After cleavage, the [Rh]-H speciescombines with the alkene and then undergoesreductive elimination.'

,,]\cs treatment of the a-bromo : jllicient reactionis applicableto

/Y i

(:

r rr()rnN-functionalizedl-alkynyl .:uJr on the regioselectivityand .r the Wilkinson catalysttogether

/--/\ i l ^,'\,/)

l

-S

*

a\a

?: , . :Jtl to the double bond in the anti-.rr]lvst. However, intramolecular i r., -,rrs in the presenceof Pd or Pt

(^A**,

(J

^,\.. K

H

+ \-R'

R=Bu 98%

o

R'Jl-.--^R'

PhcooH, PhNH2

z/-\Y/

ll

9Y

(Ph3P)3Rhcl

Phl\,le a

IJ

'o"\

--* n-\A

-,P6fi-

n\

Ph"\*

91%

-- ^rn

ltr. l L*^-Al

l

\rA"n,

o

Further extension of the method results in a direct synthesis of ketones from aldehydes and alkenes2and, in the case of an aromatic aldehyde, o-substituted aryl ketones.3 Imines of aryl ketones undergo o-alkylation.

l

1"- r.-ruYo-\-d.o{-

r35

/VH ll

v

|

+ \/,R'

i l t \*- *", (Ph3P)3RhCl '170' BUNH2

o ll

rr*a-

R'

\-7

-.-.AR,

o

f--A\z\.,.."rJun,C.-H., Lee,H. JACS 121, 880 (1999). 2Jun,C.-H., Lee, D.-Y., Lee, H., Hong, I.-8. ACIEE39,3070 (2000). rJun,C.-H., Hong, J.-B., Kim, Y.-H., Chung, K.-Y. ACIEE 39, 3440 (2000)

t(

136

Chromiurn-carbene

complexes

Chromium-carbenecomplexes.13, 82-83; 14,91-93: 15, 93-95; 16, 88-92;17, 80-84;L8,103-104; 19,98-101;20, I 10-l 11 RearrangemenL Allyloxy(aryl)carbenecomplexesare convertedto allyl aryl ketones on Pd(0)catalysis.l

/-\

\

(Ph3p)4pd

)

0

-Ecrrcot^

BuLi :

(

p \-

PhcHo BF3'OEI2

\-J

P

dienolates,respectivelY.o

co/cH2cr2

r

t-O

Reductive cyclization of chromrr the carbon chain leads to bicyclic b are assembled when conjugated c:

LO

Ic4co1u

(

. 71o/o

I

./"'

t

Cr(CO)

t l \oA *

Cycloadditions. Pyrolysis of O-alkynyl cyclopropylcarbene complexes generates fused cyclopentenones. This transformation has been exploited in a synthesis of a vitamin Dj synthon.2

OMe

. rc>Ac,tco): t t l \-/ OMe I

,Ac(co), tl vitaminD3 intermediate

*

L

R2

Highly functionalized diaryl etl 3-Substituted1,2-naphthoquinones are formed by an intramolecularreactionof o-alkenylarylcarbenecomplexes.With an electron-richaromaticnucleus,the photoinducedbenzannulation is sluggish.The useof r-butyl isocyanideinsteadof CO circumventssuchproblems.l

tutedFischercarbenecomplexesutt

ll\_x OMe

o !c4cor /

t-Bu-NC/ THF ; +

cAN

^t{

R

Meo

'

R

MeO 82Yo

A chromane synthesis is readily accomplished from pentacarbonyltetrahydropyranylidenechromium via alkylidenation and photoinduced cycloaddition.a

Dikctones. Pd(0)-catalyzed c and AII-CO give a-diketones.' '*h to furnish 1,4-diketones.'

Chmmium<arbene

137

complexes

| 15.e.1-95:16,88-92;17,

...................---.............*

rc. .lrc convertedto allyl ary1

hv / THF

OH Reductive cyclization of chromium-<arbene complexes that contain a triple bond in the carbon chain leads to bicyclic butenolides.5Five- and seven-memberedenol ethers are assembled when conjugated carbene complexes react with lithium enolates and

_J-)

dienolates,respectively.6

I -

c(co)s. r') -ilJ

a rl: t]

",,/(

z^'

1o/o

(oA*

..rrhene complexesgenerates '.nl,ritedin a synthesisof a

OMe

OMe

^

t

* a"y^"u co6 a( oli \-/

OMe

* ,1Ac.1co1u

. :aminD3intermediate

:r,\lccularreactionof o-alkenyn::.1: r . ... thc photoinducedbenzannuCl .:riumventssuchproblems.s

Lio
:,\R

R-.......:R,

o\J*"

-{-ts

R R'

OH

Diketones. Pd(0)-catalyzed coupling reactions involving ArC(ONMe+):Cr(CO)s and AII-CO give a-diketones,Ewhereas a Pd(II) catalyst mediates diacylation of alkenes to furnish 1,4-diketones.e

138

Chromium(II) cNoride Me4NO

rc(co)s

/-\ , / \ \ / /

co

MeO

i l ^ .

nrlyHn o

in PhMe

84%

in CH2Cl2

28o/o

2-Chloro- l -alken--1 Homolngation with 1,1,1-trichloroethanein the presenc alcohols. Conversion of aldehydes to complished by the CCl2-catalyzed reacuc

(_, tl * ArA Pn

o

(Ph3P)4Pd

47Yo

R-CHO +

Cl- ,Cl FCI

C'4" *Lr

| (MeCN)4PdBF4

R

Me4NYR'

t".^Y^

CrC.-

R'

R-CHO + Me3SiCl [16

c(co)s

rSakurai,H., Tanabe,K., Narasaka, K. CL75,309 (1999). 2Yan,J., Herndon, J.W. JOC 63,2325 (1998). rMerlic, C.A., Aldrich, C.C., Albaneze-Walker, J., Saghatelian,A. ,/ACS 122,3224 (ZO0O). rWeyershausen,8., Dittz, K.-H. SI, 231 (1999). sRudler, H., Parlier, A., Certal, V., Vaissennann, l. ACIEE 39, 3411 (2OOO. "Barluenga,J., Alonso, J., Rodriguez, F., Fananas,F.I. ACIEE 39,2460 (2000). TPulley,S.R., Sen, S., Vorogushin, A., Swanson,8. OL l, l72l (lggg). nSakurai,H., Tanabe,K., Narasaka, K., Yamane,M., Ishibashi,Y CZ 168 (2000). ''Yamane, M., lshibashi,Y., Sakurai,H., Narasaka,K. CL l?4 (2000). Chromium(Il)

]'

c(co)s

chloride. 13, 84; 14, 94-97l'15,95-96;

16, 93_94;17,84_g5l

Reductive cyclimtinn.s Azide redu addition of the resulting amine to a cr assemblageof fused-bridged tricycles has synthesisof ( - )-cylindricine.

18. 104:

1 9 , 1 0 1 ; 2 10 1, 1 - 1 1 3 Alcohol synthesis. Halogenated allylchromiumreagentscan be preparedand used in a reactionwith carbonylcompounds.r

oH cl O il

C

ll

Ph

l

\-/

+

H

J

f c tcl

l crc,z ph{A

('ct

;i

I

2{ -Hydroxyalkyl)cyclopropanok." generatedfrom enoneson treatment'*'rth with aldehydes afforddiol producs.

) 73%

2-Tetrahydrofuranyl ethers.2 At room temperature alcohols are derivatized into the ethers with Crclr and cclu in THF under essentially neutral conditions.

tl 'rYpr'

RC
< R

'

R>< X=Cl,Br

,.oxfAo

'

\-,

c k

r-li ' 3uOH

Insertion into silacyclopropanes.2 Remarkably regioselective reactions of silacyclopropanes with methyl formate are mediated by CuBr2 and ZnBr2. The regioselectivity is totally switched from one ofthese two salts to the other.

144

Copper(I)chloride

\Z

CuBr2

!r,k

o * \or,t" H

t ||

-

L \4 I tnr,,,

\ / --FSi-O /

I

|

Yt

\

SnMe3

OMe

- -

70o/o

*p,_o,

-l*o""

Coupling of zirconacyclopentadter sults in cyclooclatetraenes.?

7$Yo

r--dx

O rMa.S..Xie,H. OL2,3801(2000). rFranz,A.K., Woerpel,K A. ACIEE39 4295(2000)' Copper(I) chloride. 13, 85; 15, 101; 18, ll2-ll3; 19, 107-108; 20, ll8-120 of alkyl halides Oxid.ations. Carbonyl compounds are obtained from autoxidation (15 8l-997o\'l examples' and tosylatespromotedby CuCt on Kieselguhr Sterically coupling reactions. The Stille coupling is accelerated by cuCl. cucl in (Phr)+Pd, Licl, of congested substrares are readily coupled in the presence DMSO.2 stannanes Allylfurans and allylthiophenes can be synthesizedfrom the corresponding to l-chloroalkynes and by coupling with allyl halides.r The coupling of alkynylsilanes Benas C--{'a such groups furnish conjugated diynes tolerates many sensitivefunctional zotropylidenes and benzotroponeszue accessiblefrom the reaction of zirconacyclopentadieneswith 2-iodobenzylhalide and 2-iodobenzoylhalide,respectively.5

5

I

ZrCp2

y=e;H,H

and

h

CuCI-DCC via pseudoureaintermedtar Aryl radicals.e A synthetic appl CuCl is radical generation at an c-pos aminobenzoyl) derivatives in the prer which the ct-position becomeschlorina the nascentaryl radicalsis evident.

'r\r^*/\

\4,

I

Silvlq

Tertiary

Dehydration.8

I

t\r-

I

SiMe3

NH2 O l l l

Y i R 'u''z .-.-A^, co,z,\''

SaMe

SiMe3

l--s -)

^

4\)

TBSO.,,/ -O

-U

Hc

'-''-

,

r-

2,2'-Bridgedbiaryls are readily obtained from short-chain 1,to-bis(2-trimethylstannylaryl)alkanesby treatment with CuCl in DMF at room temperature'6

Pinacolatoboration.tt) Hydrotrn effected with bis(pinacolato)diboron r borylcopper species is involved in t nucelophile toward allylic halides and I

Copper(I) chloride

Etooc .cooEt

\)Z

'fo'"

_-Fsi-o

SnMe3

-\

R

70%

Y

R

R = OMe

I

{

62%

by cuCl rewith (Z,Z)-1,4-diiodo-1,3-dienes coupling of zirconacyclopentadienes in cyclooctatetraenes.t sults

SiMe3

/v\

O

-

I

ZrCP2 + SiMe3

SiMe3

MesSi

,SiMe3

Aa" "'"'. ",l-h"

| ',t2--/

i rHF Dl\'lPU

/-\

|

Me3Si

SiMe3

SiMe3

56% ). . '- 108:20,118-120 t :: ::t rutoxidation of alkYl halides r : : : :: - . r . .8 | - 9 9 7 a ) . 1 i ,-,.'lcrated bY CuCl' StericallY R-r:r'e t)f (Phi)4Pd,LiCl, CuCl in N :: r1rthe corresPondingstannanes [, r:..rlanes and l-chloroalkynesto n.:. nll grouPssuch as C-0'4 Ben-

Dehydration.s

Tertiary

and

alcohols

benzylic

undergo dehydration

with

CuC1-DCC via pseudoureaintermediates. Aryl radicals,e A synthetic application of the arenediazonium ion reduction by CuCl is radical generation at an ct-position of amines. Thus, diazotization of the N-(2aminobenzoyl) derivatives in the presence of CuCl in MeOH leads to benzamides in which the ct-position becomeschlorinated and/or methoxylated. Hydrogen abstractionby the nascentaryl radicalsis evident.

n: :::. rcactionof zirconacyclopentau. :.::. rcspectivelY.5

o Hcr.NaNo2 'iO+-\

"*;;- \2;;.?" 2

3

-

r

|

X = C l 2 6 o / o+ X = O M e 3 0 %

h : .hein 1,to-bis(2-trimethylstanny)c'.:J:llPerature.6

Pinacolatoboration.to Hydroboration of 1-alkynesto give 2-pinacolato-l-alkenes is effected with bis(pinacolato)diboron in the presence of CuCl and KOAc. Perhaps a borylcopper species is involved in the reaction. The same reagent is useful as a nucelophile toward allylic halides and Michael acceptors.

Copper(Il) chloride

..-l-".^ .u",-Licr-KoAc

. --*;4-o'-'o-l--lll

-f

".

pf

|

,*

-1-o'\

rHashemi,M.M., Beni, YA. JCR(S).434(1999). 2Han,X., Stoltz,B.M., Corey,E.J.JACS 121' 7600 (1999). 3Nudelman,N.S., Cano, C. SL 1942 (1999). lNishihara, Y., Ikegashira, K., Hirabayashi' K., Ando, J'-I', Mori' A, Hiyama' T' JOC 65' l'780 (2000). 5Takahashi, T., Sun,W.-H., Duan'Z', Shen,B. OL2,ll9'7 (2000)' 6Piers.E.. Yee, J.G.K.,Gladstone,P.L.OL2,481 (2000). TYamamoto.Y., Ohno, T., Itoh, K. CC 1543 (1999)' 8Majetich, G., Hicks, R., Okha' F. NIC 23' 129 (1999)' eHan, G., LePorte, M.G., Folmer, J.J.,Wemer, K.M., Weinreb, S'M ACIEE 39,23'l (20O0): Han' G'' (1996)' LePorte.M.G., Mclntosh, M.C., Weinreb,S.M., Parvez,M' JOC 6l' 9483 r0Takahashi,K., Ishiyama, T., Miyaura, N. CL 982 (2000).

Copper(Il) chloride. 14, 100;18, 113-114;19' 108;20,120 Halolactonization.t Allenic acids give p-halo-^y-butenolideson reaction with cuX2 (X: Cl, Br). is Coupling of organometallics. The demetallative dimerization of RLi by CuCl2 give RSnBul Organostannanes by CuI.2 different from the conjugate addition catalyzed R-R when R is an alkynyl. alkenyl.or aryl group.' Hydrolysis of SAMP-hydrazones.a After asymmetric alkylation of the SAMPof the hydrazones,it is critical to generatethe chiral ketoneswithout racemization.Treatment a solution. provides ammonia productswith cuX2 in THF or MeCN followed by aqueous

Meo'-'"'a) N,NJ

--^y^-

aEnders,D., Hundertmark,T.,Lazny, R. SC 29. :5Takahashi,T., Sun, W.-H., Nakajima' K. CC l59J

l5: 19.I Copper(I)iodide.16,98;18' 11'1-1 oi l' reaction The Alkynyl ketones.t CuI-Et.N. Cyclization. Alkynesin which the tnp from a pronucleophlicsite undergoclchua Thetriplebondis actiral CuI andt-BuOK.2

lll x. cooMe tlt

v

|

|

? - : -

\,/

=

X = C N ,C O M e , . . .

Coupling between an imino chloride arx by cyclization.3This Pd-catalyzedprocer. r able decomposition occurs and the reactlon i

o THF ; NHg

#

tl

I (99% ee)

cyclooctatetraenes.5 (z,z)-1,3-Dienyl-1,4-dicopperspeciesare formed on treatment in the of zirconacyclopentadieneswith CuCl2. Further reaction with NBS results substitutedcyclooctatetraenes. IMa,S.,Wu,S.JOC 64,9314(1999). 2Pastor, I.M.,Yus, M. TL 4l' 1589(2000). 3Kang,S.-K.,Baik,T.-G.,Jiao'X.H.,Lee,Y-T.TL40,2383(1999)'

Either pyrroles or 3-pyrrolines are form formaldehyde and CuI.a

R

nf-\ Ar

i-Pr2NEt- HCrc . Cul

r

Copper(I) iodide

o. B-d

o'

!.'

,,R

147

aEnders,D., Hundertmark,T.,Lazny, R. SC 29, 27 (1999). 5Takahashi,T., Sun, W.-H., Nakajima, K. CC 1595 (1999).

\\

\lori. A., HiYama, T. JOC 65' 1780

19,109-110:'20,120-l2l Copper(I)iodide.L6,98;18,114-115; Alkynyl kptones.t The reactionof l-alkynes with acyl halides is promotedby CuI-EtN. by threeskeletalatoms Cyclization. Alkynesin which the triple bond is separated from a pronucleophlicsite undergocyclizationin the presenceof catalyticamountsof CuI andr-BuOK.2The triple bondis activatedon coordinationwith thecoppersalt.

rx)). l.

,

, \\. 'r. S \{ ACIEE39,237(2000);Han,G., r: \1 ./()C61,9483(1996). [t'

:0. I 20 '. hutenolideson reactionwith CuX2

I

d -

, L

-.

I.

: . c dimerizationof RLi bY CuCl2 is RSnBuj give t'ul.r Organostannanes :rrnctric alkylation of the SAMP.! rrhoutracemization.Treatmentof the .-','u:ammoniaprovidesa solution.

lll t \-,

xy.coottt" Cul - IBUOK l +

COOMe

THF

X = C N ,C O M e , . . .

is accompanied Coupling betweenan imino chloride and 2,2-dimethyl-4-alkynamide by cyclization.r This Pd-catalyzed process is aided by CuI, for without which considerable decomposition occurs and the reaction also becomessluggish.

.A ff-}

Cul - Pd

46%

F

(99% ee)

r::'

Either pyrroles or 3-pyrrolines are formed when N-propargylanilines are heated with formaldehyde and CuI.a

n1o-rspeciesare formed on treatment :cuction with NBS results in the

R

I

rT\

i-PrZNEt-HcHo aq +

cula

h\ ^'

nr-'JJ

>:\

n-N?

Ar It

_,.r 1999)

in dioxane in ethanediol

Copper(I)oxide

Desilylallylatian. 2-(1-Trimethylsilylalkenyl)thiopyridinesundergo allylation. Regioselectivity differences are noted for silylallyl- and silylvinyl-type substrates.s

(r

Cu;O- 3i

rtNqz

\____Z

DMSC .r:

Z"'att , + C u l- K F THF / lVle2CO

Me?Si

f"f\

rMoreno-Manas, M., Plexixata, R.,Villarrora. S

Copper(Il) tetrafluoroborate. pNitrostyrenes.t Styrenes undergr)r

)-,,"

.-2.-J.-)

Cul - KF

Cu(BFa)2and 12in MeCN.

THF / lVe2CO

78%

rChowdhury, C., Kundu,N.G.?55, 7011(1999).

2 Bouyssi,D., Monteiro, N., Balme, G. TL 40, 1297 (1999). 3Jacobi,P.A.,Liu, H. "/ACS121, 1958 (1999). alayaprakash,K., Venkatachalam, C.S., Balasubramanian, K.K. TL 40,6493 (1999). sTakeda,T., Uruga, T., Gohroku, K., Fujiwara, T. CL82l (1999).

Copper(Il) nitrate. 15, l0l; 18, 115-116; 19, I l0:20, l2l Biaryls.' Diarylstannanesincluding heteroaromaticanalogues(furan and thiophene series) undergo reductive elimination on treatment with copper(Il) nitrate trihydrate in THF at room temperature. Azidolysis of glycidic acids.2 In the presence of copper(Il) nitrate trihydrate, regioselectivering opening of the epoxide by sodium azide in water (pH 4) to provide 3azido-2-hydroxy carboxylic acids is observed. N-Nitro-1-methyluracil,\ l-Methyluracil undergoesN-nitration with a mixture of copper(Il) nitrate trihydrate and acetic anhydride, while nitration occurs at C-5 in fuming nitric acid.

rCampos, PJ.,Garcia,B., Rodriguez, M.A r1.I

Copper(I) 2-thiophenecarboxylate.19. t I Enami.des.t Enamides are prepartrJ NMP with Cs2CO.,asbase. lShen,R.,Porco, J.A.OL2, 1333(2M).

Copper(Il) triflate. 19, I 12;20, 122-l)] Cleavage of aziridines.t Coppenllr aziridinesby arylamines. Mukaiyama aldol reaction: With C cnol etherswith aldehydescan be carriedtr Acetylation. Alcohols, thiols. and ar reactionwith aceticanhydrideat room rem

are similarly transformedinto gem-diaceta N-Arylimidazoles.s Together *irh L as additives,Cu(OTf)2and cesiumcarbona

rHarada, G.,Yoshida, M., Iyoda,M. CL 160(2000). 2Fringuelli, F.,Pizzo,F.,Vaccaro, L. SZ311 (2000). 3Giziewicz, J.,Wnuk,S.F.,Robins,M.I. JOC 64,2149(1999).

lSekar, G.,Singh, (t999r. V.K.JOC 64,2537 rKobayashi, S.,Nagayama, S.,Busujima. T. (-/-I rsaravanan, P, Singh,V.K.TL40,26ll (lD99, rChandra, K.L.,Saravanan, P.,Singh,V.K.51,ri( sKiyomori,A., Marcoux,J.-F.,Buchwald. S.t- fl

Copper(I) oxide. 16, 99 Perfluoroallcylation,t By using Cu2O as the catalyst, anilines undergo perfluoroalkylation with RrI in DMSO at 130'. The perfluoroalkyl groups enter at ortho- and para-positions that are open. N,N-Dimethylaniline suffers demethylation in the

Copper(II) trifluoromethylthiolate. 19. I I Trifluoromethylthioarenes,t Arl laml in the presenceof the title reagent.

process.

'Adams,D.J.,Goddard, A., Clark,J.H.,Macqur

Copper(tr) trifluoromethylthiolate

allylationRegiorx. ..:rJcrgo t',:--.uhstrates.s

Cu2O - CsF17,

( \

/FNH2

/

---------------------_ ceFrzl Dr,,4soi3o'

_--'"u'u ,/-\ //-* , CeFrz

: r l \

^ . / Vl

l

I 5-/o

rMoreno-Manas, M., Plexixata, R.,Villarroya,S.Sa 1996(1999).

:: \\ I '. ''-Z

Copper(Il) tetrafl uoroborate. B-Nitrostyrenes,t Styrenesundergo nitration with sodium nitrite in the presenceof Cu(BF.), and I, in MeCN. rCampos,P.J.,Garcia,8., Rodriguez,M.A. TL 4l, 9'79 (2000).

e

Copper(I) 2-thiophenecarboxylate.19, I l2; 20, 122 Enamides.t Enamides are preparedby coupling alkenyl iodides with amides in N M P w i t h C s ; C O 1 a sb a s e . J r ' : , ) r( 1 9 9 9 ) .

lShen,R..Porco,J.A.OL2, 1333Q000).

Copper(Il) triflate. 19, l 12; 20, 122-123 r.: :Lrc:(furanand thioPhene tn r : - : ' . : l l t n i t r a t ct r i h Y d r a t e . ::.crrll) nitrate trihydrate, ....itcr(pH 4) to Provide3:

Cleavage of aziri.dines.t Copper(Il) triflate is a good catalyst for cleavage of aziridinesby arylamines. Mukaiyama aldol reaction r With CutOTf), as catalyst, the condensation of silyl enol etherswith aldehydescan be carriedout in aqueousethanol. Acetylation. Alcohols, thiols, and amines are acetylated by a Cu(OTf)2-catalyzed reactionwith acetic anhydrideat room temperature.rVariousaldehydes(but not ketones) aresimilarlytransformedinto 3erz-diacetates.a

.\ r-:

'r.rtlonwith a mixture of . rlccursat C-5 in fuming

N-Arylimidazoles.5 Together with 1,10-phenanthrolineand dibenzylideneacetone as additives,Cu(OTf), and cesiumcarbonatepromoteformation of N-arylimidazoles. rSekar, (1999). G., Singh,V.K.JOC 64,253'7 rKobayashi, S.,Nagayama, S.,Busujima, T. CL'11(1999). tsaravanan, P.,Singh,V.K.TL40,26ll(1999). +Chandra, K.L.,Saravanan, P.,Singh,VK. Sa 359(2000). 5Kiyomori, A., Marcoux,J.-F.,Buchwald, S.L.fL 40, 2657(1999).

.rnilines undergo Perr,.. li'.. :roups enter at ortho- and l::- . demethylationin the

Copper(Il) trifluoromethylthiolate. 19, I 12: 20, 122-123 Trifluoromethylthioarenes.t Arylamines are converted to ATSCFTby diazotization in the presenceof the title reagent. rAdams,D.J.,Goddard, A., Clark,J.H.,Macquarrie, D.J.CC 987(2000).

150

Cyanomethylenetriorganophosphoranes

1-Cyanobenzotriazole.

p-Cyclodextrin.

Aryl cyani.des.r Cyanation of ArLi by the title compound is expedient. rHughes, T.V.,Cava,M.P.JOC 64,313(1999). N-(2-Cyanoethoxycarbonyloxy)s-uccinimide. Amine protection.t Amino groups present in oligonucleotides are readily protected with this activatedcarbonate1 in the form of carbamates.

4 I

2-Amino alcohols. Epoxides are op trimethylsilyl azide2in the presenceof p-c1r Tbrephthalic acid. Benzene is selecrr yield) in a Cu mediatedreaction with CCl. r The C-{ bond formation occurs when benz

rReddy, L.R.,Reddy,M.A., Bhanumathi. N.. R.m 2Kamal, A., Arifuddin,M., Rao,M.V.IA 10.{:61 rShiraishi, Y.,Tashiro, S.,Toshima, N. Ct 8lE , -'{

,o

Carbonylhydridotris(triphenylphmphim I Hydroformylation I Wttig reactionaccomplished.

N-O

\ o otr",\

CN

(1)

>..,

H2tco.

rManoharan, M., Prakash, T.P.,Barber-Peoc'h, I., Bhat,8., Vasquez, G., Ross,B.S.,Cook,P.D.JOC 64.64681999\.

,nre^y'

1-Cyanoimidazole. Cyanation.t This reagent is prepared from imidazole and cyanogen bromide. It donates the cyano group to various nucelophilessuch as amines, thiols, and RMgX (or RLi). rWu,Y.,Limburg,D.C.,Wilkinson,D.8.,Hamilton,G.S.OL2,795 (2000). Cyanomethylenetriorganophosphoranes. Cyanomethylenation of carbonyl compounds. This powerful Wittig reagent MeIP--CHCN reacts with esters,lactones,and imides.r The reaction is valuable for synthesis of C-glycosides fiom glyconolactones and Phrh-{HCN. Microwave shorlensreactiontime to minutes.z assistance

rBreit,B.,Zahn,S.K.ACIEE38,969 (1999t ( 1,5-Cyclooctadiene)(1,3,5-cyclooctatrier

Isomerizatinn.r 2-Allylphenol is isom (cod)Ru(cot)in methanol at room tempera Triethylphosphineis also added. rSato,T., Komine,N., Hirano,M., Komiya.S. ('/. ( 1,5-Cyclooctadiene)cyclopentadien.r-lcnb

I * .'cN pnAoet [t",

"cN

This nrttr [2 +2 +2]Cycloaddition.t alkynesand a nitrile, has beenextendedro th

PhN.4e 100'

*{o=,

R

.lll lTsunoda,T., Takagi,H., Takaba,D., Kaku, H., Ito, S. TL41,235 (2000). rlakhrissi, Y, Taillefumier, C., Lakhrissi, M., Chapleur,Y. TA ll,4l7 (2000).

I

R

clrcr r,u.

l5l

(1,5-Cyclooctadiene)cyclopentadienylcobalt

p-Cyclodextrin. nr:. ..:-,Jts exPedient

" protected F, ..-lc'rrtidesare readily

2-Amino alcohols. Epoxides are opened regioselectively with arylaminesr and trimethylsilyl azidezin the presenceof B-cyclodextrin. Tbrephthalic acid. Benzene is selectively converted to tetrephthalic acid (46 mol%o yield) in a Cu mediatedreaction with CCla in the presenceof NaOH and B-cyclodextrin.r The C-{ bond formation occurswhen benzeneis trappedin the cavity of B-cyclodextrin. rReddy, N., Rao,K.R.S4 339(2000). L.R.,Reddy,M.A., Bhanumathi, 2Kamal,A., Arifuddin,M., Rao,M.V. fA rc, 4261(1999). sshiraishi, N. CZ 828(2000). S.,Toshima, Y, Tashiro, Carbonylhydridotris(triphenylphosphine)rhodium. Hydroformylation + Wittig reactian,t The

tandem process on

alkenes is

accomplished.

/'\'\-/"\ :

H2lCO- (PhrP)3Rh(CO)H

( i . . R o s s ,8 . S . , C o o k , P . D .J O C

enre^\o

phMe eo"

etoocv,,y,,Z{ :

!l .1.:

U.

.:

-

Ic

.:'

and cyanogenbromide. It rmines, thiols, and RMgX

- < l0fx)).

r. I :rr. powerful Wittig reagent fhe reactionis valuablefor u--r ,',1 PhIP-CHCN. Microwave

:

f

.cN

i

,nAoEt

I f!

.: l r x ) 0 ) . lr :1112000)

l

O

60% (syn : anti 9:1)

lBreit.8.. Zahn.S.K.ACIEE38,969(1999\. ( 1,5-CyclooctadieneX 1,3,5-cyclooctatriene)ruthenium(0). Isomerization.r 2-Allylphenol is isomerizedto 2-propenylphenolin 957oyield with 'the (Z/E) ratio of the products is 94:6. (cod)Ru(cot) in methanol at room temperature. Triethylphosphineis also added. rSato,T., Komine,N., Hirano,M., Komiya,S. CL44l (1999). ( 1,5-Cyclooctadiene)cyclopentadienylcobalt. [2 + 2 + 2]Cycloaddition.t This method of pyridine formation, which unites two alkynesand a nitrile, has beenextendedto the synthesisof spiroannulatedanalogues.

R'

. l Il l +#1*R' I

R

r52

Cyclopentadienylbis(ethylene)cobalt

rVarela, L., Saa,C. OLl,214I (1999). J.A.,Castedo, (1,5-Cyclooctadiene)(nu-naphthalene)rhodium(I) tetrafl uoroborate. This cationic rhodium complex is useful for inducing the [4 + 2]Cycloaddition. cycloaddition ofconjugated dienesto unactivatedalkynes in dichloromethane(15", 15 min), I forming I .4-cyclohexadienes.

4 6,I \.,^ru' o2"'V

rPaik,S.-J.,Son,S.U.,Chung,Y.K.OL1,2045(1999). (1,5-CyclooctadieneXr1o-tetraphenylborato)rhodium(I). Hydroformylation. Alkynes undergo hydroformylation to afford branched-chain aldehydeslor lactones.2

co-H2 (Pho)3P / cH2ct2

t 2Y

aY

tPerez,D., Siesel, B.A.,Malas r Eichberg, M.J.,Dorta,R.L..f2

Cyclopentadienylindium( I t Cy cIop en tad ie ny lc arbin ln water.

cHo 55%

/\ \ . / (

\t/

,)-e'

*Rh(cod)

\^ t'

7.

I

lYang.Y.. Chan.T.H. JACS 122.

91o/o rvandenHoven,B.G.,Alper,H.JOC 64,3964,9640 (1999). 2vandenHoven,B.G.,El Ali, B., Alper,H. JOC 65,4131(1999). Cyclopentadienylbis(ethylene)cobalt. [2 + 2 + 2]Cycloaddition. Extension ofthis cycloaddition method to annulation of benzofuran successfullyelaboratesfour rings of the morphinoids.' A strychnine synthesis2has beencompletedbasedon an analogouselaboration.

f
::r COOET

o-\"

*

s\ l

!

+

cl

ricr4

Ph'l\,As

s^\zLoricrs / /

r

Ph

. i lopropyl-1,0-unsaturated

(-"'

:rtl out under ethylene to

-

+eZ\ v

t

*

i

l

i

pn'\.Ast\fo

RCHO

|

l

l I

R

oricr,

Ilwama,T., Kinoshita,H., Kataoka,T. TL 40,3741(1999).

Dodecylbenzenesulfonic acid. Mannich reaction. The sulfonic acid is both a Bronsted acid and a surfactant. It proves to be a most effective catalyst for promoting condensationof silyl enol ethers with aldehydesand o-anisidine.r Actually, other arylamines and ketonescan be used.2 lManabe, K., Mori,Y.,Kobayashi, S. SL 1401(1999). 2Manabe, K., Kobayashi, 5.OL1,1965(1999). :i:. .rlkylation of chiral No:- :.-.1tlonfurnishessubstituted P:., r PON., properly protected

Dysprosium. Propargylation of carbonyl compounds.r promotes formation of homopropagyl alcohols.

This metal in the presence of HgCl2

Dysprosium(Ill) trifl ate tLi,Z.,Jta,

r84

Y , Z h o u ,J . S C 3 0 , 2 5 1 5 ( 2 0 0 0 ) .

Dysprosium(Il) iodide. Alkylation of carbonyr compounds.t The Barbier-type reaction is mediated by DyI2 in THF. The reagent, possessinga reactivity pattern similar to that of (thf )JmIr, must be preparedjust before use. Reductinns') The complex (dme)iDyl2 is a reducing agent whose reactrvity lies between Birch reducing agents and Sm(II) and rm(II) salts. It can be used to convert tolane to (Z)-stilbene and naphthaleneto the r,4-dihydro derivative. rEvans,W.J.,Allen, N.T.,Ziller, J.W.JACS122,Il74g (2000).

Dysprosium(Ill)

trifl ate. cycloadditionr In the presence of Dy(orf)q aromatic aldehydes and arylamines form aldimines in situ, and then react as heterodienestoward enecarbamates.

Ethanesulfonyl azide. Azidoalkanes.r A prep peroxide to add a carbon r decomposesby extrusionof r chain reaction on.

o.o-$, rOllivier,

C., Renaud,P r{(i

,

ll:

BnOOC. BnOOC

j"r1

\

\,/

.,')2

Dy(OT03

iR'

IVeCN

')7

R+ \

2-Ethoxy-1-ethoxycarbong I Activation of *hydrot temperature. Whenan aminer n v

lBatey,R.A., Simoncic,pD., Lin, D., Smyj, R.p., Lough, A.J. CC 651(19gg)

tl \ , \ 'ot * HzN\ Y OH

rHyun,M.H.,Kang, M.H..Han.S

Ethylaluminum sesquichlorN Frtedel-Crafts alblab chloroformate acts as an alkrle

11 ( / * o rBiermann. U . . M e t z g e rJ. . O .. . 1 ( 7

Irrsprosium(Ill)triflate

lM

r-:.rc rcaction is mediatedbY r. ':nrilar to that of (thf ).TmI2' r:.- .11!-ntwhose reactivity lies r..r- lt can be used to convert -rltve.

d;:.

Ethanesulfonyl azide. Azid.oalkanes.r A preparation of RNj from RI involves initiation by dilauroyl peroxide to add a carbon radical to a nitrogen atom of the reagent. The adduct decomposesby extrusion of sulfur dioxide and an ethyl radical, the latter then carries the chain reaction on.

*o$r

. ?uri'

dilauroylperoxide PhCl/ heptane

o.o$*.

a

, .rldehydesand arylamines -'nccarbamates.

84To lOllivier,C., Renaud,P.JACS122,6496(2000).

BnOOC. 2-Ethoxy- 1-ethoxycarbonyl- 1,2-dihydroquinoline. Activation of u-hydroxy acids.t The derivatization is complete at room temperature.When an amine is present,the carboxyl group is transformed into an amide.

,

l()qg)

o tl \ ,/\. / 'on + HzN'v Y

e).\ t

\,

OH

i

l

tl \ ,/\ ,'^\. ./ Y

l

ru oet cooEt

N

V

5HH 97Yo

lHyun,M.H.,Kang,M.H.,Han,S.C.TL40,3435(1999). Ethylaluminum sesquichloride. alkylation.t Under the influence Friedel-Crafts chloroformate acts as an alkylating agent for alkenes.

O. ",io! rBiermann, J.O.ACIEE38,3675(1999). U., Metzger,

of

EtiAl2cli

isopropyl

186

Ethyl diphenylphosphonoacetate

N-Ethyl-2-bromo-4-methylthiazolium tetrafl uoroborate. Peptide couplings,t This reagent is particularly useful for coupling of hindered amino acid derivatives. rLi,P.,Xu,J.C.TL 40,8301 (1999).

rAndo,K., Oishi,T.,Hirama.\l .

Ethylenebis(triphenylphospl Alkylation.t Displacenr nucleophiles occurs in the pre

Ethyl N-benzyloxycarbonyloxamide. Gabriel synthesis.t Following N-alkylation of the oxamide, selective saponification removes the ethyl ester to afford RNHCOOBn. The N-Boc derivative is similarly transformed.

o o *oot.f\cooEt Rooc.N&cooEr'B"oIlDMF,

LioH

o

4A','oec'

H

ROOC.

R ' O

H I I

cl

N K

R = t B u .B n

Hydroboration and bon lato)diboron is mediated h1 r ketones(a net regioselecrrreI undergoborativecoupling *rd

'Berree,F.,Bazureau, J.-P,Michelot,G.,Le Corre,M. SC29. 2685,1999). Ethyl cr-chloro.or-phenylselenoacetate.

* Ph7\,

,n{

Pictet-Spengler cyclization.t Ethyl tetrahydroquinoline-1-carboxylatesare readily preparedfrom a reaction (catalyzed by SnClo) of phenethylaminesand the ester. lSilveira,C.C.,Bemardi,C.R.,Braga,A.L.,Kaufman, T.S.T4 40, 4969(1999). f -Ethyl-3-(3-dimethylaminopropyl)carbodiimide. Dehydration.t a-Substituted cinnamic esters are obtained stereoselectively from the benzylic alcohols[anli-alcohols-> (E)-alkenes;syn-alcohols-> (Z)-alkenesl.

N,-\

OH

tl

tn"^lrCooMe I L

F unctionalization of aILl thio groups to alkynes.Disulf is regioselectiveand stereo,.,e lc

+

tl

r,'N

nreq

Me2NJ

I

cucr2

'*;:

Cl

pht\y'COOM"

(,.oras 99lo

' S a iH . . ,O h m i z uH. . T L 4 0 . 5 0 1(91 9 9 9 ) . Ethyl diphenylphosphonoacetate. Emmons-Wadworth reaction.t (Z)-2-Alkenoic esters are the overwhelmingly major products. The reaction is carried out in the presenceof DBU and NaI.

( \ ) CoH +

S $

+

\ \ / cl

rKadota,J., Katsuragi, H.. Fu\unx rLawson,YG., Lesley, M.J.G.. \L 'suginome, M., Nakamura.H.. \L 'Han, L.-B., Tanaka.M. JACS lll

Ethylenebis(triphenylphosphine)platinum(0)

rAndo. K., Oishi, T., Hirama, M., Ohno, H., Ibuka, T. JOC 65' 4'745(20oo).

l.

!.:.r. l()r coupling of hindered

Ethylenebis(triphenylphosphine)platinum(0). acetateby of thevinylic chlorineof 2-chloropropen-2-yl Alkylation.l Displacement of thePt complex. occursin thepresence nucleophiles

tr:: .,lc.'elective saponification \ . lJ,'e derivative is similarlY

lc : =:

R O O C . - . ,H N l,

LroH

K

i' ' 4)--,,-,oAc

I

--J

.a.oo=, v\

ll-ereena,

Na*

! I

.,1999).

r'^..../.OPh 53%

Hydroboration and borative coupling. O,C-Diboration of enones by bis(pinacolato)diboron is mediated by the Pt-complex.2 Hydrolysis of the adducts gives B-boryl ketones (a net regioselective hydroboration of the conjugated double bond). 1,3-Dienes undergo borative coupling with B-silylpinacolatoborane in the presenceof aldehydes'1

qlk ,, Ph
(Z)-alkenesl.

u.

Functionalization of alkynes.a The Pt-complex catalyzes the addition of silyl and thio groups to alkynes. Disulfides and disilanes are sources of the addends.The reaction is regioselectiveand stereoselective.

cl

., Ph"\acooMe (-.ores ;

C1

CoHrs +

99To

\ \\ cl

c.r.:. cr

ilfc the overwhelmingly

: [)BU and Nal.

S -5

//

CoHrs

ll - ptrpptr.t,

tl . "'tt'rr,",. +

P h l \ , l e1 1 0 ' ; Et3N/ EIOH

ct
r;:

phcooEt

-

l

A propargylic carbonate or phosp via the allenyltitanatespecies.e

Certain 2-alkylidenecycloalkano lar processinitiatedby cyclotitanarro

88% (trans j cls 93 : 7)

4\\(n

Reaction with alkenes and aWnes. In the carbosilylation of alkenes and dienes with carbon fragment that comes from a secondary or tertiary alkyl halide, promotion by BuMgBr/Cp2TiCl2 is efficient. Primary alkyl halides are less suitable contributors unless the reaction is intramolecular. The regioselectvity of this process is such that the silyl group is branched out.5

ph,,/ -

ll

ti l ll r o

't

I

K

-cp2ricr2>tn7f4BuMscr tBuBr. Et3SiCl

I

c+^ii

94%

tn6A.Ar,.

I

BuMgCl- Cp2TiCl2 MetSiCl

,,.YO Me3Si

Reductive cleavages. Dia4l dl BuMgBr/Cp2TiCl2 system. Alkl.-lar respectively.

Both the removal of the ester gru (alsoArBr, ArI)ra are accomplishedar Allyl ethersand allylaminesun&r rcgioselectivelyaccordingto the rrtan

87% /-)

o.

Hydrotitanation of l-silyl- and l-stannyl-l-alkynes leads to B-silyl (or Bstannyl)alkenyltitanates,6 thus showingoppositeregioselectivityto other relatedprocesses (hydroboration,hydroalumination,hydromagnesiation,hydrotitanation,hydrozincation, hydrozirconation).Well-defined alkenes are obtained on further reaction of the alkenyltitanates,for example,with allylic carbonatesan Sx2' displacementoccursto afford 1,4-dienes.7If another alkyne is added before protonation of the titanacyclopropenes(to give the alkenyltitanates),then the intermediates are transformed into titanacyclopentadienes, and henceto conjugateddienes.n

\_-2

XY o-

rll R

R^Tix3 Me3Si..".-[Ml

*.iJ

I

Er--C

+ Cp:T + EBT

t"rt') SiMe3

t-\

f).* \-J

ll -------.---.-(i.Pro.-

M= B,Ms,At,zn,zr

Cyclization. If a proper learrng ,liene,an opportunity for eliminarionc resultingalkyltitanium speciesmar hc hasbeendevelopedaccordingly.

Grignard reagents-titanium{IVlcompounds

Measirt-Ph - ,oH

i:-

A propargylic carbonate or phosphonatemay be converted to a hydrazino derivative via the allenyltitanatespecies.e Certain 2-alkylidenecycloalkanols are synthesizedfrom alkynones by an intramolecular processinitiated by cyclotitanationof the triple bond.r0

88%(trans:cis 93 : 7)

.di.n

r- .rlrlation of alkenesand dienes o: ::1ritn' alkyl halide, promotion by r tr:- ..\s suitablecontributorsunless r,' ''i- processis such that the silyl

-,

Y

c

'h,

Y/\ l Et.si

-,/ l I

94%

:- ^ltn

flf 'l'

3

.L{* -(tsPro)ari i-PrN'4scr ; Ytot ll R'^x

R'

X = H ,l n=1,2

Reductive cleavages. Diaryl disulfidesrrand ditelluridesr2are cleaved with the rBuMgBr/Cp2TiC12system. Alkylation results in alkyl aryl sulfides and tellurides, respectively. Both the removal of the ester group from a B-ketoesterrrand dechlorinationof ArCl (alsoArBr, ArI)ra are accomplishedat room temperature. Allyl ethersand allylaminesundergodimerization,rswhereas 1,6-dienesare cyclized regioselectivelyaccordingto the titanium complexesused.ro

Me3Si 87Yo

1-},o,,

.:rc\ leads to B-silYl (or Pprocesses t ' ' r.tl\ ity to other related 'i hydrozincation. r tlrotitanation. 1: '' iunher reactionof the alkenyltit\: .:-l.rccmentoccursto afford 1,4-di(to give : thc titanacycloProPenes

r-

: :Ic'd into titanacyclopentadienes,

\-J ,/-\ o ll \_-,

(i.pro)ari

H HOJ

\_OH

( d l: m e s o > 9 6 : 4 ) 51%

)") *,,,,Fo,

\

?

f1o

a'

B fJ,,,,-OME -N.

t2

OMe

Bn

/

6 \

UIJ

,,R, \_1

to-\-42t"

| \o/^ ),,,r'-,,-lt"

n=1,2

Bicyclization involving an intramolecularacylation is further extendedto include an aldolization.reA route to bicyclic enoneis basedon controlledprotonolysisof the titanacycle and subsequentcyclization.This synthesisis amenableto asymmetricinduction.20

Homoenolate and homoalleayl cnolate speciesare basedon the actrq titanatesgeneratedfrom acetalsof rm

iicetals are similarly cleaved to a.f carbonates are transformed into r l compoundswith ^y-selectivity.rr

rO. t F o

ior-^ | /-w

a)

.Y ................"'..".'................'"."'..................................* "\

\-\'o '

i-PrN,lgBr-(i-PrO)aTi ; s-BUOH

l-42:-siMe.

I SiMe3

T t

-\_/ /

-q .a n 17

\-/

54Yo The possibility of forming a bridged tricyclic system by an intramolecular reaction of an imide2ris of syntheticsignificance.

.v

I

I

H 1 9

\.,N : H

N

Z

U

R

G"n"'

.........................................._ (i-PrO)3TiCl ;

X

O2

The Cp2TiPh species generatedfrom addition of PhMgBr to the l-PrMgBr-Cp2TiCl2 system is able to induce cyclization of D-ketonitriles to cyclopentanolones.22The vinylogues afford 2-hydroxycyclopentaneacetonitriles.

t"-.

Following activation of conjugared c rmines gives products with multiple srer

Me?Si _P2 '-icl2

\\

..--_ [cornpt i_prMscl

\ '\2. R'

a,a-Dimethylamines.26 Reductnt reaction with MeMgBr in the presenceol

Grignard reagents-titanium(IV)compounds

J

--cooH

l "'te

/--(o

\-f,

\..r\cooH N

H

c

OH rP

r-4, t

Cp2TiCl2

(

i-PrMgCl; PhMgBr

\-f-J

H

H

77%

(-)-kainicacid

r h o te l

)

CN Cp2f i0l2

x

i-PrN,lgCl PhMgBr

^

K

R

/

' 64Yo

\o-\.,42t" H

i. lurther extendedto include an [. '::r()llcd protonolysisof the titanan 'r.rhlc to asymmetricinduction'2o a::'-

Homoenolate and homoallenyl carbanion equivalents. Two routes to homoenolate species are based on the action of (propene)titanium diisopropoxide. Trialkoxytitanatesgeneratedfrom acetalsofacrolein react with aldehydesand imines. Chiral cyclic acetals are similarly cleaved to afford the nucleophiles.zr3-Alkoxy-2-propyn-l-yl carbonates are transformed into (l-alkoxyallen)-1-yltitanatesthat add to carbonyl compoundswith T-selectivity.2l

n ./v,

.^)

l F o

).'

/-+/I \ ^

'>J

\

o

I SiMe3

Cp2TiCl2 i-Pr[rgcl I

*-*4*'

a) -

ron ,,-)""'\-o,,r1n' NHR" \_,/

54% ;r . - :: hr an intramolecularreactionof

Following activationof conjugatedenynes,the reactionwith carbonylcompoundsand iminesgivesproductswith multiplestereocenters.z5

:

:

N^Ph

Me"Si

^-ict2 vP2l

\

\ '\2. '

R

'

+ [complex] i-PrMscl :

tl

HN^Pn Me?Si -

l,/zv

r' tr

r : t'!\leBr to the i-PrMgBr{P2TiClt The vinyr: :- :,, cvclopentanolones.22

.4{a,' R'

a"a-Dimethylamines.26 Reductive methylation of tertiary amides occurs on reaction with MeMgBr in the presenceof TiClo @r ZrCl) in THF.

Grignard reagents-zirconiumcompounds 'Cho, S.Y.,Cha, J.K. OL2, 133'7(2000). 2Raiman,M.V, il'ina, N.A., Kulinkovich, O.G. Sa 1053 (1999). 3Winsel, H., Gazizova,Y., Kulinkovich, O.G., Pavlov, V., de Meijers, A. SL 1999 (1999). lMizojiri, R., Urabe,H., Sato,F.TL40,2557 (1999). 5Nii, S., Terao,J., Kambe, N. ,/oC 65, 5291 (2000). 6Urabe,H., Hamada, T., Sato, F. JACS 121,2931 (1999). TOkamoto, S., Takayama,Y., Gao, Y, Sato, F. S 975 (2000). 8Hamada,T., Suzuki, D., Urabe, H., Sato, F. JACS l2l,'1342 (1999). ' An, D.K., Hirakawa,K., Okamoto,S., Sato,F. TL 40,3'137(1999). r0Morlender-Vais, N., Solodovnikova,N., Marek, I. CC 1849 (2000). I lHuang, X., Zheng, W.-X . SC 29, 1297 (1999). r2Huang,X., Zheng,W.-X. SC 30, 1365 (2000). r3Yu,Y., Zhang,Y. SC 29,243 (1999). raHara,R., Sato, K., Sun, W.-H., Takahashi,T. CC 845 (1999). rsdeMeijere, A., Stecker,B., Kourdioukov,A., Williams, C.M. S 929 (2000). 'oOkamoto, S., Livinghouse, T. OM 19,1449 (2000). rTCampbell,A.D., Raynham,T.M., Taylor,RJ.K. CC 245 (1999). rsTakayama, Y, Okamoto,S., Sato,P. JACS l2l,3559 (1999). reOkamoto,S., Subburaj, K., Sato, F. JACS 122, 11244 (2000). 20Urabe,H., Hideura,D., Sato,F. OL2,38l (2000). 2 r S u n gM , . J . ,L e e ,C . - W , C h a ,J . K . S L 5 6 l ( 1 9 9 9 ) . 22Yamamoto, Y., Matsumi, D., Hattori, R., Itoh, K. JOC 64,3224 (1999). 2iTeng,X., Takayama,Y, Okamoto,S., Sato,F. JACS l2l,11916 (1999). 24Hanazawa,T., Okamoto, S., Sato, F. OL2,2369 (2000). zsHamada,T., Mizojiri, R., Urabe, H., Sato,F. JACS 122,7138 (2000). 26Denton,S.M., Wood, A. Sa 55 (1999).

Grignard

reagents-zinc

Reductive

alkylation.

*/

lvlgB

l,S-Dienes and l,S-envnttnentenes(derived from alkr.rrs. rre treated with alkynylmetals. h s ith iodine gives 1,5-enynes.

Cp2ZrCt2 K:K

R

EtMsBr

Cp-Z)

Alkenylcyclopropanes.a

Th

borohydride. Esters

are converted

to

secondary

alcohols

where

the

F.tMgBr and Cp2ZrCl2 converr-s r}r

G r i g n a r d r e a g e n tc o n t r i b u t e s o n e a l k y l g r o u p . l

R'MgBr

R.

R_COOEI +

Zn(BHiz

FOH R,'

rHallouis,S., Saluzzo,C., Amouroux, R. SC 30, 313 (2000).

Grignard reagents-zirconium compounds. 18, 174; 19, 1611,20, 180-1 8 I Organozincation.t On reaction with EtMgBr-Cp2Z{12, 1-alkenesgive 2-substituted dialkylzincs that can be usedin coupling reactions. Alkylsilanes.2 Grignard reagents are isomerized by Cp2ZrCl2.Subsequentreaction with hydrosilanes in the presenceof an alkyl bromide leads to silanes bearing a primary alkyl group.

Gagneur,S., Montchamp,J.-L.. \egu t'ra, Y., Hara, R., Takahashi.T. CC tl Dumond,Y.,Negishi,E. JACS l2l. l' 'Bertus, P, Gandon,V, Szymonral-J

ztl

Grignard reagents-zirconium compounds

R \

: , \ l e r l e r sA. SL 1999(1999).

i [r, -:r_ 1999). . :-:- rq99).

. ._.:rxn).

Cp2ZrCl2

t

Y MgBr

R. z'\ v siHPh2

B(CH2)3Br Ph2siH2

7,S-Dicnes and 1,S-enynes,3 Insertion reaction takes place when zirconacyclopentenes(derived from alkynes, ethylmagnesium bromide, and zirconocene dichloride) are treated with alkynylmetals. Protodemetallation leads to l,5-dienes, whereas oxidation with iodine gives 1,5-enynes.

R \: \ 919(2000).

!.

cp2ztct2

*t-J*

R'---€-rvi

CpZr

':t

D--E-D

R

/\

EtMsBr Cp2ZrJ

/

)

-

I i - , ,

*
-{.

MeS _. / P

t

/:\

(,

,/

\\

\ FO

/ \

h

//

N

6HF

+ \

Hs(OTf)z cH.cr2 67o/o

(

r,)n ot' arylselenideanionsbY

rj

s ith hydrazinchYdrateover a

t." t\

Desilylation. Desilylation promoted by 3HF-EtiN in THF constitutes the key step accessof a-azido ketones.6 in an enantioselective

rls(1999).

-^rtl

: , t n a n . S . . R a o , B . S . J C R ( S )6 7 4

tl

);)si.-

I

!rroup to pyrandionesis bY rtltluctswith HN1 eliminate

NHz \-n

----.-o Dh

THF O"

86To

l-Aryl-3-hexenopyranosiduloses.r 2-Acetoxyglycals serve as electrophiles toward arenesin a reaction that introduces an aryl group to C- I of the sugar moiety.

o"o\,_., / \ /

_

N3

Et3N-3 HF

nco"

AcO

\

v

/ OAc

94lo

( h a d a . R . K . , C o u l a d o u r o sE , .A.

rDinoiu, V., Fukuhara,T., Hara, S., Yoneda,N. JFC 103, 75 (2000). rShellhamer, V.L.,Syvret,R.G., J.M.,Heasley, T.L.,Stringer, B.J.,Pettus, D.F.,Horney,M.J.,Pettus, Dobrolsky,J.M.JOC 64, 1094(1999). 'Lubke,M., Skupin,R.,Haufe,G. JFC 102,125(1999).

216

Hydrogen peroxide, acidic

aKanie, K., Tanaka,Y., Suzuki, K., Kuroboshi, M., Hiyama, T. BCSJ 73,471 (1999). 5Hara,S., Okamoto, S., Narahara,M., Fukuhara,T., Yoneda,N. SL 411 (1999). 6Enders,D., Klein, D. SL719 (1999). THayashi,M., Nakayama, S., Kawabata, H. CC 1329 (2000).

Hydrogen

Rov,A., Reddy,K.R.,Mohanta. P_K.. ll

iodide.

Hydrodechlorination,

salts are dechlorinated

B-Chlorovinamidinium

by

HI

in

dioxane.r

*'f '*'

Y"' \*-*' R

PFo

* - *' l'l- rru

"'' \,

dioxane

Hp'drogen peroxide, basic. 13. I J5 Oxidations. Mildly basic co rlkenes.rFor epoxidationof,*ater u rcry similar system is useful for r srfluoroalkyl group to furnish alcol c-Formylpyrroles yield 2-p1'rroh

MeOOC

\

\r-*' R

/-coolte

(L""o

IDavies,I.W.,Taylol M., Hughes, D., Reider,PL OL2,3385(2000). Hydrogen peroxide. Activation, Catalystsfor alkene epoxidation with H202 include perfluoroheptadecan7-one,r butyl 2,4-bis(perfluorooctyl)phenyl selenide,2phenyldibutylarsine,3and HReOatriphenylarsine.aFor ring contraction of cycloalkanones,an oligomeric 9,1O-bis(diseleno)anthraceneeffectively promotes the action of hydrogen peroxide.sPolyfluorinated alcohols such as hexafluoroisopropanolalso activate hydrogen peroxide toward epoxidation and Baeyer-Mlliger oxidation.6 Oxidations. Alkene formation from alkyl aryl selenidesvia oxidation is cleanerwhen the aryl group is ort o-substituted(vs. para-substitution), for example, with a nitro group.T In the presenceof a phase-transfercatalyst,oxidation of aldehydesto carboxylic acids8with H2O2is successfullycarried out without an organic solvent,halide, or metal ion. rvanVliet,M.C.A.,Arends,LW.C.E.,Sheldon, R.A. CC 263( 1999). 2Betzemeier, 8., Lhermitte, F.,Knochel,P.SL489(1999). rvanVliet,M.C.A.,Arends,I.W.C.E., R.A. 7L 40, 5239(1999). Sheldon, avanVliet,M.C.A.,Arends,LW.C.E.,Sheldon, R.A.JCS(P/)3'17(20W). 5Giurg,M., Mlochowski, J. SC29,2281(1999). 6Neimann, K., Neumann, R. OL2,2861(2000). TSayama, S.,Onami,T. TL 41,5557(2000). nSato, K., Hyodo,M., Takagi,J.,Aoki,M., Noyori,R. TL 41,1439(2000). Hydrogen peroxide, acidic. 14, l'16; 15, 167-168; 16, 177-778; 17, 145; 18, I 82-l 83; 19,1661'20,187 Degradation of acylarenes,r Such carbonyl compounds are readily converted to phenols with hydrogen peroxide-boric acid.

Yao,H., Richardson,D.E. JACS 122. .r: Falck,J.R., Lai, J.-Y.,Ramana,D.\'.. tr Pichon-Santander, C., Scon,A.l. fL {1.

H1'drogen peroxide,

metal catalp

: Bf l 85; 19, 166-167; 20, I 88 Nitrones. N-Alkyl a-amino r nrtrones.l

Ph'^Nlrcoo

Oxidative esterification.: Thc nethyl estersin methanol (perchlorx Bromination,t Brominating ag .rtu from tetrabutylammoniumbromt

Oxidation,a In the presenceof 'ridized by H2O2-Na2W0. to affm rnd secondary alcohols, respecrtr

Hydrogen peroxide, metal catalysts

8('s"/73. 471(1999). .1 ll l (1999).

a

&

Roy,A., Reddy,K.R., Mohanta,P.K.,Ila, H., Junjappa,H. SC 29,3781 (1999).

Hydrogen peroxide, basic. 13, 145;14,156; L5, 167;18,183-184; 20, 187-188 Oxidations. Mildly basic conditions (NaHCOl) have been used to epoxidize r. are dechlorinated by HI in

:

rlkenes.r For epoxidation of water insoluble substrates,aq MeCN is a suitable medium. A very similar system is useful for oxidative cleavage of organostannanescontaining a perfluoroalkylgroup to furnish alcohols.2 a-Formylpyrrolesyield 2-pyrrolinones.r

- _R'

\

MeOOC

)r\ * ' * '

\

ll

fcooMe

COOMe H2O2- NaHCO3

\N'/.-cHo H

I f(

85%

t:.{ : r|()).

s::: ll O; includeperfluoroheptadecanand HReOaIr :'rcnvldibutylarsine,3 r -.. .rn oligomeric9,10-bis(diseleno)rs: ' :.t rorid€.5 Polyfluorinated alcohols x-

;r:roxide toward epoxidation and

I r -:::ticsvia oxidationis cleanerwhen tirr example,with a nitro group.T u:. to carboxylicacidsowith r ' .,.Jc'hydes , r m e t a li o n . r . . : . t .h r l i d e o :.

'")c)

).

Yao, H., Richardson, D.E. JACS 122,3220 (2000). -Falck,J.R., Lai, J.-Y, Ramana,D.V., Lee, S.-c. fa 40, 2715 (1999). ' Pichon-Santander,C., Scott, A.I. TL 41,2825 (2000).

Hydrogenperoxide,metalcatalysts . 13, 145;14, 177;15,294;17,146-148;18, I 84-185;19, 166-167 ; 20, I 88 Nitrones, N-Alkyl o-amino acids undergooxidative decarboxylationto afford nitrones.l

pnAruAcoon]11';1ll ph,'\iz\ EtaNUl- K2UU3 | { H2o

S'-:.tr1999). :-- i1000). i;

-.ll

::9 r1000).

. 1 6 ..

-r-178; 1 7 ,1 4 5 1 ; 8,

are readilyconvertedto | - 'r)p()unds

cH2ct2

O-

70%

Oxidative esterification,2 The H2O2-V2O5reagent converts aromatic aldehydes to methyl estersin methanol (perchloric acid is also present). Bromination.3 Brominating agent for activated arenes (e.g., phenols) is formed in situ from tetrabutylammonium bromide (oxidation by H2O2-V2O5). Oxidation.a In the presenceof a phase-transfercatalyst (BuaNHSOa),alcohols are oxidized by H2O2-Na2WOato afford either carboxylic acids or ketones (from primary and secondary alcohols, respectively). Because of its easiness in separation and

Ilydrosilanes

regeneration the heterogeneouscatalyst WOFSiO2 is useful for cleaving cyclopentene with H2O2to glutaraldehyde.s Nitriles.b Copper powder and various copper salts catalyze the conversion of aldehydesto nitriles by ammonia and H2O2in isopropanol. ' Ohtake,H., Imada,Y., Murahashi,S.-I.BCSJ 72, 2'137 (1999). 2Gopinath, R.,Patel,B.K. OL2,577 (20M). 3Bora,U., Bose,G., Chaudhuri, M.K., Dhar,S.S.,Gopinath, R., Khan,A.T.,Patel,B.K. OL 2,247

:nterestingly,direct deoxygenarr( rossiblewith Et.SiH and a caralrrrc Regioselectivity is imponanritr rtion of the two hydroxyl group\ rn :hat the combinationof Et.SiH *rrt :.0-O-benzylidenesugars' i: r.'n

rr drosilaneis catalyzedby PdtOAc r

(2000). 4Bogdal,D., Lukasiewicz,M. SZ 143(2000). 5Jin,R.,Xia, X., Xue,D., Deng,I.-F.CL3'71(1999). 6Erman, M.B.,SnowJ.W.,Williams,MJ.TL41,6749 (2O0O).

Dh---\-n-1 \ v /-\n

Bno'

/

/\;/ --OBn BnO

\

^ \

NHAc

Hydrogen sulfide. Alkyl poxoalkanedithioates.t The combination of H2S-BFj.OEI2 dealkylate one of the S-substituentsof acyl ketene dithioacetals in refluxing dioxane.

Thiono estersand lactones;rc c t:t,B.s Partial dechlorinationof Fr.lr

Ph

\\ )-SMe MeS

Rh-phosphinecatalystproceed.rn h

o

H2S- BF3.OEt2 dioxane A

S MeS

Cl

"'J'o

67Yo

\v a-Silyl enethiols.2 Acylsilanes react with hydrogen sulfide to provide a-silylated enethiols.A route to thiolactones passesthrough such intermediates.

Symmetricaltetraaryldisilanerrp :rrcly perlbrms hydrodehalogenarr rdductswith activatedalkenes.

r\

o ll tn-r,\.^aoo" /

\

s

H r S- H C I ;

- NaHCO3

H tn-si'\,^"oort I

,i\

tl S/\ t tn'a,'\r/

al

l

/ \

rNair,S.K.,Asokan,C.V.SC29,'191(1999). 2Bonini,B.F.,Comes-Franchini, M., Fochi,M., Mazzanti, G.,Ricci,A. 54 486(1999).

Hydrosilanes. 19, 167-169; 20, 188-192 Defunctionalizatinn, Hydrosilanes are better reagents than hydrostannanes for deoxygenation of alcohols via their xanthates.Thus, reasonablygood results are obtained by using the symmetrical tetraphenyldisilane under free radical conditions.l More

/" P-",*

X = SOzPh,COOEI

Reductions. Ketones are rcdtrc -()mplex(Ph,P)AuClcatalyzeshrdrr :. a precatalystin the reduction of

Hydrosilanes

f)

:- useful for cleaving cyclopentene

of Di!: .alts catalyze the conversion p{ l-rn,rl.

|.*,' ;r:,:

R..Khan,A.T.,Patel,B.K. OL2'247

interestingly, direct deoxygenation of primary alcohols and cleavage of ethers are possiblewith EtrSiH and a catalyticamountof (CoFs)rB.r Regioselectivityis important for reductivering opening of cyclic acetalsas differentiation of the two hydroxyl groups in a diol systemis often desiredin synthesis.The fact that the combinationof Et.SiH with TfOH and PhBCl2 operatein the oppositesenseon -1.6-O-benzylidene sugarsr is very valuable. Note that cleavageof benzyl esters with hydrosilaneis catalyzedby PdtOAcl'.i

t{-\$3-"'"'ruHn"

:: :-

enoy'"'N2"--OBn BnO

Thiono estersand lactonesare convertedto ethersby Ph2SiH2and catalytic PhrSnH, FlrrB.sPartial dechlorinationof polychloroareneswith triethylsilaneand a homogencous Rh-phosphinecatalystproceedsin high yields.6

Ph

\o )-t MeS t'

o -cooH

cl I \a\

cl

,\

Y

96%

Symmetricaltetraaryldisilanes(preparedtiom Ar2SiH2and Cp.TiPh2 at 120') efl'ecrivcly perfonns hydrodehalogenation.iHowevcr, the radical intermediatesreadily form .rdductswith activatedalkenes.

,il'.-.; /

-7-\

l(

I

t4'*

i**:::r reagents than hydrostannanes for Tl-.-.. rcasonablygood results are obtained re -rrJ!'r free radical conditions'l More

\/

lRhl

cl

Ph.si,\,/

r!:: (; . Rrcci.A. SL486(1999)'

t'Y\

Et?siH- Ph3P

i l l

I r...r:rr!eo sulfide to provide o-silylated t.,-r rntermediates.

\

NHAc

87%

,r of H2S-BFj.OEI2 dealkYlate one :lu\ing dioxane.

67Yo

?-

Hor5Si\.ov"

..:.r-:,r:: r\'4s4A7cH2cr2

eno-A9y'rn

la:

Bno-\

Er.siH- roH

+

'/ x ./\u

Ph

\

Ph>

.-7---

l(

|

AtsN/;;i LHlx

X = SOzPh,COOEI,PO(OE02

47-887o

A gold Reductions. Ketonesare reducedwith trialkoxysilane-histidinecomplexes.n .omplex (Ph,P)AuCl catalyzeshydrosilylationof the C:O group." Dibenzenechromium :. a precatalystin the reductionof aryl carbonyl compounds."'A systemcomprising

Hvdrosilanes

hydrosilaneand a copper salt has selectivereducingpower for ketonesand double bonds conjugatedto an aromaticring.r1For saturationof the enonedoublebond, a choicecan be made of PhMezSiH with the tris(triphenylphosphine)copper(I)fluoride-bisethanol adductrr or PhSiHj and Mn(dpm)..l:rReduction of esters to alcohols can use either diphenylsilanein the presenceof the [(cod)RhCl], complexraor trimethoxysilaneand t l MeOLi in THFr5 c a t a l y t i ca m o u n o Benzyl ethers can be prepared from THP ethers by the MejSiOTf'-catalyzed reaction with PhCHO and EtrSiH.r6Analogously,amides.carbamates,and ureasare N-alkylated with aldehydesfollowedby in situ reductionwith Et,SiH.r7The aldevia condensation hyde may be replacedby a thioesterthat is subjectto reductionin situ. Thus, a mixture of sodium triacetoxyborohydride, tricthylsilane,and Pd-C catalystis employed.rx

N

o H z

P hvv[\ o / v \ '

n '

o-r,,^"[r,o H o 5 s = ,

MeOOC r--Z X MeOOC \'

+ Me3si-o-si{H

Cyclization and hydrosrlrlatr :' process. Cp*.Y Me-catalyzed

o-l s* , l M e 3 S i O '- f Sl i - H

o

,-\

mainlr crc able.rl5,7-Alkadienals

Pd/c NaBH(OAc)3

-yo

\2

When the Pd-inducedclclrratr drosilane,the productsbecomt-h properhydrosilanes(e.g.. pentanx

W"^i'ovMl,n r^) F) - Y o ' n - ^ y o l O )< 93%

to oxcpancsis ellected A regioselective conversionof6,8-dioxabicyclo[3.2.1]octanes by a TiCla-catalyzed reductionwith EtrSiH.r') Benzyl azides undergo rearrangement-reductiontandem to allbrd N-methylarylamincsr0on treatmentwith Et.rSiH-Sncl1. Hydrosilylation. Allyl alcohols form cyclic structurcs in a Rh-catalyzedhydro-

n = 33-35

Dehydrogenative silylatioasrth r derivatives by hydrosilanes catalyst,respectively. Peptide synthesis.:" An \.

deblockedby a combination -o

O X/ "

$n-o--r-t\ anb lrn

rtsrcszcu /\-n t

- Et3B | Bu3snH

I

|

\-,/-'--J

Y

Tohma, H., Takizawa' S ' \le I-riedrich,H.B.' Singh' \ IL .\dam, W., Gelalcha,FG ' Sr ' . \ d a m , W . ,S t e g m a n n , V R' 5 Boto, A., Hernandez.R ' Sur Wakao, M., Fukase, K" Kusr

5S% p -Iodotoluene (2000)' rsmietana, M., Gouverneur,V' Mioskowski 'C' TL 41.'193

,;;-d*" j., viur,c., Bols,M. cEJ6, 1140(2000)' r' sr1le3(2000)' :.'*;;;;I *1.,ruau,A.,lsobe,Y',Yajima'

./

Flo_ Bi'o

by NlS-induced cyclization'

OMe I

):(

/ v \

BnOO*"

BnOo*.

GlYcosYlation'6 Oxrda Me,SiOTf furnishes actrsatc s hen such a thioglYcoside ts

difl uorkla

FluorocYclization' HF-pYridine.

p-Iodotoluenedifluoride

re.r ::,'rn.ArOH,EtzZn,and CH2I2,is a r. .:c rransformedinto cyclopropanes r ' : :ractivity, the zinc phenoxide is ,}.:.\. than bis(iodomethyl)zincand

!n

-. :./ , rfxYll

Iodosylbenzene.13, 15I ; 16, 186; 18, 194; 19, 17g; 20, 2Ol oxidations. By using phl:o (in presence of KBr) as an oxidant, alcohols are oxidized to acids and ketones in water in excellent yields.rwhen catalyzed by either poly(4-vinylpyridine)-supported sodium ruthenate2 or a (salen)chromium complex3 chemoselective oxidation of alcohols (e.g., allylic alcohols to alkenoic acids) occurs. which is contrary to the effect of (salen)manganeseand (porphyrin)iron complexes (giving epoxy alcohols).a oxidative decarboxylatinn,s o-Amino acid derivatives undergo degradation by PhI:O/Iz.

:l;:.: .rndthe silver salt of saccaharin. a:.:.e.. Iodohydrinsare formed when

\/ I

N--(

v . b

Phl=O- lz cH2ct2

cooH 82o/o I te. 177-178 hr.::.r. l'rom alkenesinvolvesthe use n r..: .t\ cxemplifiedin the following.z

Glycosylation.6 oxidation of phenylthioglycosides with phl:o in the presenceof MqSiOTf furnishes activated glycosyl donors. Stereoselectiveglycosylation is achieved when such a thioglycoside is clamped to another sugar component.

(-\

._o)
,/.OH I

x.:--

Y

:000).

ll

I OH

HO

*4

---;-

50x2-200 _COOH Dowex

98o/o

itJirnt convertssaturatedalcoholsor tg..r.J.

F

- ,.'_io

//:\ | \:/

Desulfinylation.s Sulfinamides are methanolyzed to the corresponding amines in the presenceof an ion exchangeresin. Deoxygenation of epoxy ketones. An alkali metal halide on Amberlyst 15 is capable of removing the epoxide group from epoxy ketones.6Interestingly, LiBr or NaBr, insteadof LiI, also brominatesthe enonesat the o-position.T

\- /.\ 74%

Irn:nr:rtes to oxazOlidin-2-onesvla TI,]I

o

po

N H

o

A

xo

ffi6

l - \ lt

t 15> lAmberlvsr LiBr

ol lt>rr, \

-1//

72%

a::nercd on admixture with Bu+NF,

|:.., ti .re t5t5 (2000).

.arhoxylic acids are selectively x:. r .r- I 5 resin.r Alkenoic and aroic ll:. rrrrmdt€ to a dicarboxylic acid t.:

ou:'.-5(JWX2.2

'Anand,R.C.,Vimal,A.M. JCR(S) (1999). 378 rNishiguchi,T., Ishii,Y., Fujisaki, S. ,/CS(p1)3023(tggg). rYoung, J.,Jung,L., Cheng, K. TL4l,34lt,34l5 (2000). {dela Hoz,A., Moreno,A., Yazquez,E. Sl, 608(1999). :Li, G.,Kim,S.H.,Wei,H.-X.756,719(2000). "Bovicelli,P.,Righi,G., Sperandio, A. T 56,1733(2000). -Bovicelli, P.,Righi,G.,Sperandio, A,.TL40,5889(1999).

Iridium complexes. Isomerization. cationic iridium complex effects selective isomerization of unsymmetrical diallyl ethersr and conjugated boronatescontaining an allylic ether group, including an accessto "y-(siloxy)allylboronicesters.2The conversionof allyl homoallyl ethersto ^y,6-unsaturated carbonyl compounds3is promoted by [(cod)IrCl]r.

238

Iridium complexes

*y*'gto [(cod)rrcr]?

*>-o.--r\ R' ' l

+

\r,r'

Cy3P-cs2co3

Il

I

\r/\

I j{#I|l

Ph'v2'-..,.o.v,\

Ph\t2'...-,.o.-Z\ 78%

(

\J

F

O-\-1/

+ \

Iron. 19, 179-180;20,20-1-: y-Lactones.t In the pre halogenated esters.

[(Ph2MeP)21(cod)]PF6

(

F

O

H2trHF

6

8

"\:1

\J %

'Suda, K., Baba,K., Nakajima. S 'Adams, R.D., Bamard,T.S.. Bnx ^Matsuda, I., Hasegawa,y.. \tahl -Petra, D.G.I., Kamer, PC.J.. Spl (2000). 'Takeuchi, R., Tanabe,K. ACIEE : "Matsumoto, T., Taube,D.J.. penr

\

(i,;

/-l

I , ll rl

(Tetraphenylporphyrin)iridium(Ill) triflate isomerizes terminal epoxides to aldehydes in refluxing dioxane.a 1,3-Diaxolanes.s Epoxides and ketones combine under the influence of [Cp*Ir(MeCN)rl@Fe)2. Aldol reaction 6 A new catalyst for the Mukaiyama version of an aldol reaction is [Ir(cod)(PPhj)2]OTf. Actually, after activation by hydrogen, it promotes a Michael reaction of enones with silyl enol ethers and the svstem can be modified to continue an aldol reaction. Reduction. Certain successhas been achieved in transfer hydrogenation of ketones (from HCOOH, Et.N) using [Ir(cod)Cl]2 and a chiral ligand.? Sp2' dhplacement.s Employment of an iridium complex instead of the more commonly used palladium catalysts successfully mediates regioselective allylic displacement.

1^fcoou" I I ----Acr

Somech,L, Shvo,Y. JOMC f{ l. I

Iron(II) chloride. 20,2U Chloroamination.t Deco by iron(Il) chlorideleadsto lar n tl

q Na*

*

Etooc^cooEt

I(cod)lrCll2

,\

.N3

t

\"^\-

E

//--\

R

\

'e: -

\

(Pho)3Pl rHF ETOOC"\COOEt

OAc 94Yo

Friedel-Crafis allqlation,e A straighrchain alkyl group can be introduced into an aromatic nucleus by reaction with an alkene, using the binuclear Ir(III) complex, as caralyst.The result is remarkablydifferent [Ir(p-acac-O,O,C3)-(acac-O.O)(acac-Cr)]r, from the commonly known reaction pathway. rYamamoto, Y., Fujikawa,R., Miyaura,N. SC30, 2383(2000). 2Yamamoto, Y., Miyairi, T., Ohmura,T., Miyaura,N. JOC &,296 (2000). 3Higashino,T., Sakaguchi, S.,Ishii,Y. OL 2, 4193(2OOO).

Alky lativ e r earran gemcnL : diazo compounds(particularll tropic rearrangement:ue induce
" . a)^cooMe

oAl.r"

n FeCl2- Me3siCl + EtoH 0 - 25'

tl on tttt

tl +

1'.-",

\

EIOOC"'\COOEt

oANH

R

cl

( 9 : 1 )

94Yo

tr .:.rr I group can be introducedinto an i. ...r:rs the binuclear Ir(IlI) complex, r:. . -: The result is remarkably different

Alkylntive rearrangement.2 Sulfonium ylide formation from allylic sulfides and diazo compounds(particularly trimethylsilyldiazomethane)and subsequent[2.3]sigmatropic rearrangementare induced by (dppe)FeCl2in 1,2-dichloroethane.

R,..'..R t _ " ' (r .,{ tq6 (2000). I

Il \-SR"

* f r-siMe3 N2

(dppe)Fect2 *;

; n - K \ s-f'i H , r e g

clcH2cH2cl \

Iron(III) chloride rBach, T., Schlummet B., Harms, K. CC 28'7(2000). rCarter. D.S.. Van Vranken. D.L. OL 2. 1303 (2000).

Iron(IID chloride. 13,133-134;14,164-165;15, 158-159; 16,167-169, 190-l9l;17, 138-139; 18, I97 ; 19, 180-18I ; 20, 204-205 Acetylation. Either alcoholsr or methoxymethyl ethers2 are transformed into acetatesin the FeCl3 -catalyzedacetylation, using HOAc and Ac2O, respectively. Michael reactions. 2-Alkylidene derivatives of 1,3-dicarbonyl compounds behave as donors in Michael reactions. Of particular interest is the formation of biaryl precursors with quinones.l

b

Cyclopentenonesare formed t at the ct-position.TCommon lrrr this cyclization.

, i

'I

39%

Benzils.a Benzoinsare readily oxidized by FeClj'6H2O without solventat - 80". Cyclobutenediones and p-benzoquinones.5 Iron carbonyl species are formed by reaction of the FeClr-NaBH4 system with carbon monoxide. When alkynes are present,

pyridines in the presence of FeCl,

thev are converted to cvclobutenedionesor benzoouinonesin situ.

with r-butyl hydroperoxide.

*.'--/o CO / HOAC Mel / THF 25"

\

R

ill

o |

,"",.-r,r".

-ffi-

rHF 7s'

-"\

R

\r

+

f^*

o

(65 : 35)

B-Keto esters condense *rrh t-Butylation.u

FeCl, is an c

rSharma,G.V.M., Mahalingham. .{ I ( I 999). rBosch,M.P., Petschen,I., Guerrcn . 'Christoffers, J., Mann, A. EJOC :5ll rZhou, Y.-M., Ye, X.-R., Xin. X.-Q 5( 'Rameshkumar, C., Periasamy.\t ()-\ "Wang, Y., Arif, A.M., West, F.G ./.{(: -Kuroda, C., Koshio. H. CL 961 r:m 'Chibiryaev, A.M., De Kimpe. \ . Tllr "Liguori. L.. Bjorsvik. H.-R., Fonram

Iron(IID nitrate. 20, 205-206 Dehydrogenation.t Hy'draz ArN:NCONHNHAT

Cyclization. The oxyallyl intermediate derived from treatment of a crossconjugated dienone with FeClr is trapped by an intramolecular [4 + 3]cycloaddition if one of the a-positions of the dienone is connectedto a diene. Interesting tricyclic systems can be producedin this Nazarovcyclization.6

by grindrng Oxidative alcoholysis.: Ac1 the presenceof iron(III) nirrare

Oxidation.3 Oxidation of ak is accomplished by mixing *'irh I and crushedtogether) and wirh mx

Iron(III) nitrate

l'.

R' .

I 59: 16, 167-169,190-79I; 17,

tl

FeCl3

'\*

cH2ct2 -30'

/.:l H / o\.j

/-1

.

\,\fl \,y' ."'\ /\'/ .""\ x2 --\

--\

R mr'::.,,I ethersz are transformed into H( ) \. .rndAc2O,respectively. l : ...r-dicarbonylcompoundsbehave t.' .. rhr' tormationof biaryl precursors

H

, oy_^

R=Me R = Ph

R 65% 72Yo

Cyclopentenonesare formed by treatment of dienals bearing a silylmethyl substituent at the a-position.T Common Lewis acids other than FeClj are not effective for mediatins this cyclization.

R = Me

t : :

r,H:O without solventat - 80o. : earbonyl speciesare formed by 'r,'ride. When alkynes are present,

lL::

:rl' in sttu.

ix t -

78To

B-Keto esterscondensewith conjugatedoximes at 150.-160" to afford substituted pyridinesin the presenceof FeClj.8 t-Butylation.e FeCl is an effective catalyst for electrophilic aromatic substitution with t-butyl hydroperoxide. rSharma, G.V.M',Mahalingham, A.K., Nagarajan, M., Ilangovan, A., Radhakrishnan, B. sll200 ( 1999). rBosch,M.P.,Petschen, I., Guerrero, A. S 300(2000). 'Chrisroffers. J.. Mann,A. EJOC251I{ 1999t. 'Zhou.Y-M.. Ye.X.-R..Xin.X.-e. SC 29,2229tts99t. 'Ramesh,kumar. C.. Periasamy. M. OM lg, 2400e0001. "Wang,Y.,Arif, A.M., West,F.c. JACS121.876 ,1ggg). Kuroda.C.. Koshio.H. CL 962(2000). *Chibiryaev, A.M., De Kimpe,N., Tkachev,A.V. TL 41,80l l (2000). "Liguori,L., Bjorsvik, H.-R.,Fontana, F.,Bosco,D., Galimberti, L., Minisci,F.Joc 64,g8r20999).

t

Iron(II!

35)

lc::.:J trom treatment of a cross::'.r:,,nr()lecular [4 + 3]cycloadditionif I :, .' Jrcne.Interestingtricyclic systems

nitrate. 20, 205-206 Dehydrogenation.t Hydrazides (fuNHNH)2co are dehydrogenated to afford AIN:NCONHNHAT by grinding with Fe(NO.)..9H2O. Oxidative alcoholysis.2 Acylsilanes are converted to esters in alcoholic solvent in the presenceof iron(III) nirrate. Oxidation.3 Oxidation of alcohols to carbonyl compoundsin solvent-freeconditions is accomplished by mixing with Fe(Nor).'9H2o-HZSM-5 zeolite (in equivalent weight and crushedtogether)and with microwave assistance.

Iron pentacarbonyl

Radical cyclization. Internal trapping of the radical generated during cleavage of a siloxycyclopropane with Fe(NOr)q leads to a new cyclic array.aVarious radical terminators can be used to functionalize a remote oosition.

/

BnO

(65-7s%o\

lRl / DMF

"(il. A dramatic change in the fate of the first radical intermediates is observed when Cu(OAc)2 is also presentin the reaction media.5

,|:, Fe(NO3)3

f;*-* I

Me3SiO

;

R = H , C l ,S P h

Fe(NO3)3

,,;,

s

-lI I

rn

t t \-,\,,/

Terent'ev,A.B., Vasil'eva.TT _ Belokon,Yu.N.RCB 48. I lll r I :Taber,D.F., Kanai, K., Jiang.e.

Iron(III) perchlorate.20. :O Transetherification. A differentethers. Rilter reaction 2 Ironrll arnidesfrom nitrilesandbenz

Salehi,P.,Irandoost,M.. Seddrg 'Salehi,P, Motlagh,A.R. .tCJ0. I

l

41Yo

Iron(Il) sulfate. Acetalizafion.t Spir<x1

Fe(Nos):_

'oLon

"'ffi:"'

HO--J \-oH 48Yo

rWang,H., Wang,Y.-L.,Zhang, G., Li, J.-P.,Wang,X.-Y.SC30, 1425(2000). 2Patrocinio, A.F.,Moran,P.J.S. SC30, 1419(2000). rHeravi,M.M.,Ajami,D.,Aghapoor, K., Ghassemzadeh, M. CC 833(1999). 4Blake, A.J.,Highton,A.J.,Majid,T.N.,Simpkins, N.S.OZ l,1787 (1999). 5Booker-Milbum, K.I., Cox,B., Grady,M., Halley,F.,Marrison,S. TL 41, 4651(2000).

Iron pentacarbonyl. 13, | 52; 18, 196; 20, 206-207 Reformatsky reaction.t The Fe(CO)5-I2 combination promotes Reformatsky reactlons. Cyclohexenones,2 Carbonylation and cyclization of alkenylcyclopropanes leading to cyclohexenones with Fe(CO)5 under carbon monoxide constitute an enantioselective process.

Hydrochlortnation.: Ad FeSOois stereoselective. rhe p t O-P-chlorovinyl ketones.

,"oo-

Jin, T.-S.,Ma, Y-R., Li, T.-S..\\'a! -Conde,J.J., Martucci, M.. Olsrn, I

Iron(II) sulfate

tr

:.,::.el senerated during cleavageof a r^ . .,.:e arrar.' \'arious radical terminao:

o

(

V

Fe(CO)s/ CO i-PrOH

BnO

A.'"o"^t"(

ano.,,.-,1'-r!j

(/

c 59%

R = H, Cl, SPh

. :

(65-757o)

15%

**' NA' Mvsov, EI.,rkonnikov, NS,Kuzne,sov, Nyu.,

#ii]i;l,i;#l

ffi:;l'3' -Taber, D.F.,Kanai, K.,Jiang, e., Bui,G..)ACS 122,6807 (2000\. Iron(IIf perchlorate.20, 207 :i.:.-:l

rnterrnediatesis observedwhen

oru"!!X!tJr#ii!"o"".,

Allyticandbenzylic ethers reactwith an alcoholto sive

Ritter reaction'2 Iron(III) perchlorate supported on silica can be used ro prepare amides from nitriles and benzylic alcohols.

Y: ;.

n "\-h -

l

\-\-, 41o/o

FK,rhhmasebi, ,:liili,l, il11i"111;T Dpsc30,1743 (2000) 31"1i?lii;ff;l"n-| Iron(II) sulfate. Acetalization.t Spirocyclicdiacetals arereadilyprepared.

r F

48To

'] .t -1{).1425(2000).

74_99% Hydrochrorinatioz.2 ,

r \1 ('C833(1999). ' . t.t787 Q999). Ii.,- .,,n.S.TL 41,4651(2000).

,Hffi;*:;;ff;:..'

Addition of hydrochroric acld to ynones in the presence of products

*"In t -*f,-i-propynI -ones beingpredominantly

l',,'nrbination promotes Reformatsky t-r:rr,,oof alkenylcyclopropanes leading m.,':.,,rrdeconstitutean enantioselective

Y.-R., Li, r.-s.,

wang,J.-X.JCR(S) ll",T.{:,Ma, 26s(lsss). -Conde, J.J.,Marrucci,M., Olsen, M. TL 41,4709(2000\.

N-Isocyanotriphenyliminophosphorane

Iron(III) sulfate. Nitriles.t Dehydration of aldoximes with iron(Ilf sulfate occurs in refluxing benzene. Esterificatian.2 Aroic acids and mandelic acid can be esterified in the presenceof iron(ID sulfate.

Lanthanum(Ill) trifl uorw Aziridines.t The highl lcetatesin protic media uscs

rDesai,D.G.,Swami,S.S.,Mahale,G.D.SC30' 1623(2000). 2Zrang,G.S.,Gong,H. SC 29,154'7(1999).

N-Isocyanotriphenyliminophosphorane. a-Diazokctones.l Reaction of acid chlorides with this reagent provides chlorohydrazones,which on treatment with EtrN delivers the diazoketones'

,;,;;

veol>.)

o -cN

...

* l]-- cH2cl2 ;^: ;\'*-*', I itpn.

Cyclizatinn of epoxy aL rnfluencedby molecularsierr

2,J I

Ct

7SYo

rAller. E., Molina, P., Lorenzo, A. SL 526 (2O0O).

\ie. W.,Fang,J.,Li, J.,Wang.P Tokiwano, T., Fujiwara.K.. \lru

Lead(IV) acetate.13, 155-l t09-2 I 0 a-Siloxy acetates. o-S Ph(OAc)avia a radical Brmt Acetoxylation 2 p-t-rr

Oxidative dearonotit lactonizationis critical touar need.l

OH

I

a.ir^r \.\oire

.ulfate occurs in refluxing l.tc'nfied in the presenceof Lanthanum(Ill)

l:'

:rr. reagent provides chloro. . kc'to0es.

^reolY^\

: !

trifl uoromethanesulfona te. 20, 209 Aziridines't The highly cls-selective cycloaddition between imines and diazoacetatesin protic media useslanthanum triflate as catalyst. crclization of epoxy alcohors.2 The regioselectivity of this cyclization is greatly influencedby molecularsieves.

-{

\ , N 'NH2 Y/

/

, Ho-

oH La(orr): - na"o-"',f.-\

MeoH-cH?crz

Meo

.

.,,..(o)

cl

* rot..i"u".

i

,

9 88

*, o"lr, J.,Li, J.,wang,p.G.r ss,12s2s (tgsg). I':: Tokiwano, T., Fujiwara,K., Murai, A. CL272 (2000).

Lead(IV) acetate.13, 155_156;14, t8g; 16,193_194; lg,2Ol_202;19, 184_185; 20, 209-2t0 a'silaxy acetates. cr-Silyl alcohors are transformed into a-siloxy acehte with Pb(OAc)ovia a radical Brook rearrangement.r Acetoxylation 2 B-Lactams undergo acetoxylation at the B_position. oxidative dearomatization. The modification of a naphthol by oxidative lactonization is criticar toward a synthesis of lactonamycin. Lead(IV) acetatefulfills this need.3

OH

,-cooH Pb(OAc)4

cH2ct2

OMe 74Yo

Lipases

Cleavage

of catechols,a

Lead(IV)

acetate is much

superior

to CuCl-pyridine-

methanol in the ring cleavage. rParedes.M.D.. Alonso. R. JOC 65,2292 (2000). zciang, L.T., Fetter, J., Kajtar-Peredy,M., Lempert, K., Czira, G. 255, 13741 (1999). 3Cox,C., Danishefsky,S.J.OL2,3493 (2000). lwalsh, J.G., Furlong, P.J.,Byrne, L.A., Gilheany,D.G. 255, 11519(1999).

Lipases. 17, 133- 134: 18, 202-204; 19' I 85- I 88 ; 20, 2l l-212 Resolutions. The following types of substrates have been resolved via lipasemediatedenantioselectiveesterification:malic and asparticesters,r3-hydroxyalken-1-yl p-tolyl sulfoxides,2 B-hydroxy sulfoxides.3 A practical method involves sequential transacetylationand sulfation, followed by extraction and treatment of the aqueouslayer with methanolic HCI to recover the alcohol (the organic layer yields the acetate).4The use of 1-ethoxyvinylacetateas acetyldonor in thesereactionshas beenproposed.s Coupled with in situ racemization of the unacetylated enantiomer by a ruthenium complex, the complete conversion of a secondaryalcohol to the chiral acetateis efficient.6 An alternative method involves hydrogenation of alkenyl acetatesin the presenceof both l i p a s ea n da R u l l l ) c a t a l y s t . T Simultaneousresolutionof both acetateand amine with lipasehas beencarriedout.n Alcoholysis of B-lactonesprovidesoptically active B-hydroxy estersin one-halfof the original quantities.' Kinetic resolution.t(r Allylic alcoholsare resolvedwith a combinationof lipaseand a (p-cymene)rutheniumcomplex. Ammonolysis.rr A preparationof primary amides catalyzedby lipase proceedsin ionic liquids at leastas well as in organicmedia. Partial hydrolysis and esterifi.catinn. Aryl esters are hydrolyzed in the presenceof alkyf esters (e.g., methyl salicylate from the O-benzoyl derivative), and esters of from vinyl acetateto o-dihydroxyarenesundergopartial hydrolysis.12'r:rTransacetylation hydroxymethylphenolsoccursat the primary alcohol sites.ra Cleavage of N,N-dimethylhydrazones.ts Ketones are recovered from the lipasecatalyzedreactionin good yields exceptthe highly hinderedmembers(e'g', menthone). lLiljeblad,A., Kanerva, L.T.TA 10,4405(1999). rdela Rosa.V.G..Ordonez, M., Llera,J.M.TA ll, 2991(2000). rMedio-Simon. T.,Asensio, G. TA 10,561(1999). M.. Gil. J..Aleman,P.,Varea, aYamano, S.,Miwa,K., Kawada,M., Ito,T., Ikemoto,T., Tomimatsu, T., Kikumoto,F.,Yamamoto, K.. Mizuno.Y. CL 448(2000). sKita,Y.,Takebe, Y.,Murata,K., Nata,T.,Akai,S../OC65,83 (2000). 6Koh,J.H.,Jung,H.M.,Kim,M.-J.,Pak,1.TL40,6281 (1999). 7Jung, H.M.,Koh,J.H.,Kim, M.-J.,Park,J. OL2,248'7(2000). 8Garcia-Urdiales, F.,Gotor,V. TA ll, 1459(2000). E.,Rebolledo, eNelson, K.L. JOC 65,1227(2OO0). S.G.,Spencer, l{)Lee, D., Huh,E.A.,Kim, M.-J.,Jung,H.M.,Koh,J.H.,Park,J. OL 2,2371(2000).

' 'Lau, R.M., van Rantwijk. F.. ::Nair, R.V., Shukta,M.R.. Prr rrCiuffreda,P.,Casati,S.. Sar 'Parmar, V.S., Prasad, A-K-.

( 1999). :iMino, T., Matsuda,T.. Hiran

Lithium. 13, 157-158:15. Deaminatian.t Th€ lines ani suffersdetachmen a-Silylamines.2 THF.

Red

Azzena. U., Dessanti, F..Ilcll -Bolourtchian, M., Badnan.A

I-ithium-liquid ammonir (E)-Alkenes.) The sc with LilNH.,. Reduction of hetcrwt

Brandsma, L., Nieuwenhurz '\lcComas,C.C.,VanVrantc

l.ithium aluminum hydri Reductian of amidctreduction of morpholine I room temperaturetakespl. rlo not behavesimilarly.

A

H N _

>-Y F

O

a-Ketols,3 Reduction r with standardhydrolytic w l-alkanones. Hydrogenation ol aI raturatedby LiAlHo{eC|..

Lithium aluminum hydride r " ...h \uperior to CuCl-pyridine-

/ 5 5 . 1 3 7 4 1( 1 9 9 9 ) .

71: !:

rrLau, R.M., van Rantwijk, F., Seddon,K.R., Sheldon,R.A. OL2,4189 (2000). r2Nair,R.V., Shukla, M.R., Patil, p.N., Salunkhe, M.M. SC 29, 167t (1999). rsCiuffreda, P., Casati, S., Santaniello, E. T 56,317 (2000). 'uParmar,V.S., Prasad, A.K., Pati, H.N., Kumar, R., Azim, A., Roy, S., Errington, W. BC 27, llg ( 1999). r5Mino, T., Matsuda, T., Hiramatsu, D., Yamashita,M. TL 41,1461 (2000).

.'< l l l F o \-,^r'r 'an

Ho\4 N

\lagnesium iodide. 20, 232 Pynolidines.t Pyrrolidrn (F O r

,/ \-^

ETOOC rv

Pri

31Yo

N-T'

Mgl2 / THF

Pn)l

t

.'N

I Fpr, \

I

a a

coNPh2

t c

'\lper,P.B.,Meyers,c., Lerchner, A., Siegel,D.R.,carrerra,E.M. ACIEE3g,3rg6 (1999). \langanese. 20, 233_234 Active manganese.t A convenient procedure lbr the preparation consists of r-t'duction of Li2Mncl, with Li /2-phenylpyridinein 'fHF at room temperature.lt converts ''rganohalogencompoundsinto species reactivetoward phCocr, enonesand conJugated r'st€rs,and alkenyl halides. Benzylmanganesesurfonates.2 A preparation of these reagentsis by direct reaction ''i tosylatesand mesyrateswith Rieke manganesein THF at room temperature. They :-*havesimilarly to Grignardreagents. Cahiez, G., Martin,A., Delacroix, T. TL 40,6107(lggg). Kim,S.-H.,Rieke,R. D. TL 40,4931 (1gg9). \langanese(Ill)acetate.13,.l7l;14,197_199;16,200;17,175_176;1g,229_230; 19. 209-2 | 0 : 20, 234_235 Perfluoroalkyration.t Introduction of a perfluoroarkyr group to c-3 of coumarrns by :eactionof sodiumperfluoroalkanesulfinates is mediatedby Mn(OAc)j.2H2O. a'-Functionalization of enones. Introduction of phenyr and acetoxy groups to the o'-position of 3-alkoxy-2-cycloalkenones (five- and six-membered)is carried our ln one ()perationby reactionwith Mn(oAc). in benzeneor a halobenzene.2

-{
A

l l l \-,)-Z

,o o

12o/o

lFavre-Reguillon, A., Segat-Diour_r'. F. \t sL 868(2000).

Nitrogen dioxide. 15,219: 18, 2-s1-'r Decarbamoylation.t Prima4 an ment with NO2.

rCollet,H., Boiteau,L., Taillades. J..Coma

Nitrolic acids. Nitrile oxides.r Nitrolic acids u DMSO containing HOAc and Na-\O. nitrile oxides.

I

Y)r\'^o-< \.,,\Z 85%

HO-.*.-O NN-(1-Adamantyl) amides.z Adamantyl radical is formed by hydrogen absrraction. In situ interception with a nitrile results in the generationof the amide. 'Grossi,L., Strazzari, S.IOC g,8076 (1999). 2Eikawa, M., Sakaguchi, S.,Ishii,Y. JOC9,4676 (lggg).

2-Nitrobenzenesulfonamide. Primary amines.t After N-alkoxycarbonylation (Boc, cbz, etc.) of the sulfonamide, alkylation at the nitrogen atom and treatment with a thiolate anion complete the preparationof a protectedprimary amine.

HO' INo'

ll------*

Rt"

R"

rMatt,C.,Gissot,A., Wagner, A., Mios\or

4-Nitrophenyl formate. N-Formylationr Protectionoi a amines are selectively formylated.

'Orelli,L.R.,Garcia,M.B.,Niemevz. F. Fe

4-Nitrophenyl formate

: :- .. 1000)l Olivero, S., Dunach, E. Zl

oYof

oYot'

\

\

o-r^-N.^

,.t;:-*t

- 5 O'l

7Y*o, \r'

o1-o\f R.sNa +"-il-*\

K

cF3cooH --.--..-.---.----RNHz

i\t'lo' i l l

v

Er:.:. .()lvent (air is present)to give rFukuyama, T.,Cheung, M., Kan,T. Sa 1301(1999). o\.:-rlhalimide, NO is used as an 2-Nitrobenzenesulfonyl chloride. Sulfonamides.r The reagent sulfonylates the primary amino group(s) of a polyamine.

o v .' e._'

--ru * l - -lu

Z-'r_-\ l l \.,2-J

o

120/o

rFavre-Reguillon, A., Segat-Dioury, F.,Nait-Bouda, L., Cosma,C., Siaugue, J.-M.,Foos,J.,Guy,A. sz 868(2000).

Nitrogen dioxide. 15, 219; 18, 252-253 Decarbamoylation.t Primary amines are recovered from monoalkylureas on treatment with NO2. lCollet,H., Boiteau,L., Taillades,J.,Comrneyras, A . TL 40,3355(1999).

I a a

I

F o I a

, {

'a

7 t

ra

-

c f

r /

?

;21''a'cuo

\-,V

Nitrolic acids. Nitrile oxi.des,r Nitrolic acids are prepared from nitroalkanes or alkyl bromides in DMSO containing HOAc and NaNO2. They decomposeunder neutral conditions to afford nitrile oxides.

no-;-o ll

| :. :,'nned by hydrogen abstraction lt: :: ,'l the amide.

R)

to-,| rNozr

+

2'a'

ll

R

N.,

THF A

N-O

n{2-n'

rMatt,C.,Gissot,A., Wagner, A., Mioskowski, C. TL 41,1191(2000).

n li t. Cbz, etc.) of the sulfonamide, rr::. .1 thiolate anion complete the

4-Nitrophenyl formate. N-FormylationI Protection of amino group takes place by transacylation. Primary amines are selectively formylated. rOrelli,L.R.,Garcia,M.B.,Niemevz, F.,Perillo,l.A. SC29, 1819(1999).

9 , -

Nitrosonium tetrafluoroborat€

4-Nitrophenyl trifl ate. Transtriflationr The title compound transfer its Tfgroup to various alcohols under mild conditions (K2COq-DMfl room temperature). rNeuville,L., Bigot,A., Dau,M.E.T.H.,Zh'.t,J.JOC 64,7638(tggg).

Nitrosonium tetrafl uorobor ate.| 4, 2 | 5 ; 19, 230; 20, 262 Oxidation of dienes.t The conjugated diene unit at the terminus of certain carboxylic acids is subject to oxidation via the tricarbonyliron complexes. Activation by ligand exchange from a carbonyl to a nitrosyl group precipitates an electrophilic attack and subsequenttransformations.

Organoaluminumreagents. Allyl alcohols. Stereoselec enablescreationof quaternan'cartw Sp2'displacement with cuprares.

Y

* -ArA

r--+c{o

-tr1"o" ( )

-l\-1-"oo,.

NOBFa; Et3N

\

HON

........................* MeCN

I, I, I - Trifluoro-3-alkyn-2-ok. trifluoroethyltosylatewith lithium d theprecursors of theseuniquealcoh

n =1 , 2

'Yeh, M.-C.P.,Chuang,L.-W., Hsieh,Y.-S.,Tsai,

M.-S. CC 805 (1999). a,\

CFe +

\

,nolor.

'Spino,C.,Beaulieu, C. ACIEE39. tgt{r ' 2Matsutani, H., Kusumoto, T..Hivama.T

Organocopper reagents. 13, :07-:0 2O1-218; 18, 25'l-262: 19, 232-: -15

Silylcuprations. Alkynes and I further applications.Thus, a synrherr

tfdf- *Yo

"r

rr

I: rroup to variousalcoholsunder

,ri)g ).

:0.:b:

?:.- ..nlt at the terminus of certain f,i.-- 1\liron complexes.Activation by o:: :-r.'cipitatesan electrophilic attack

Organoaluminum reagents. Atlyl alcohots. Stereoselectiveaddition of alkenylaluminums to chiral aldehydes enablescreation of quaternarycarbon centersat the allylic position after esterification and with cuprates.r Sx2' displacement

I,l 'l - a

76To

s a 1,1,1-Trifluoro-3-alkyn-2-ols. Substitution of optically active 1-benzyloxy-2,2,2trifluoroethyl tosylate with lithium alkynylaluminates is an excellent method for accessto of theseuniquealcohols.2 the precursors

2z

il

tQt

- a

ft'

*

9r,

t'\

Bno^ors

-R

Et3Ar i Et2o BnO\.

-R 77To

I Spino, C., Beaulieu,C. ACIEE 39, 1930 (2000). 2Matsutani, H., Kusumoto, T., Hiyama, T. CL 529 (1999).

Organocopperreagents.13,207-209; 14,218-219;15,221-221; 16,232-238;17, 207-218; 18,257-262; 19' 232-235; 20,264-267 Silylcuprations. Alkynes and allenesare readily convertedto usefulreagentsfor is readilyachived.' Thus,a synthesisof B-silyl alaninederivatives furtherapplications.

*Yo tfdt'-

"r

(Me3Si)2Cu(CN)Li2 IHF -78'

*Yo tfoft'""'

"r

79Yo

:::7 :t

'"" - 1

Organocopperreagents

To direct a ring formation2 following the silylcupration is also synthetically sisnificant.

vl" /\:

t ^

-1^tc'l

-N-

oAo

_*

o4o

(PhMe2Si)2Cu(CN)Li2 THF -78. - 25"

Addition of organocuprat€Sro rT Dimethyl sulfide stabilizes the cupca reaction medium.s

SiMe2Ph 6SVo

A route to 3-silylmethyl-1,4-alkadienesrinvolves silylcupration of allenesand trapping of the ensuing organocopperspecieswith allyl phosphate. The 3-silyl-propen-2-ylcopper reagentderived from allene is used to react with enones and the products can be cyclized to give 3-methylenecyclopentanols.a

The conjugate addition-trapping p nates.Under CO carbonylationoccun formed.e

R2Cu(CN)L|2 * A i

'nvtl( o

* nnu"rsi -(

-40'

n

tn)t'-Ja

BF3/ THF

PhMezSi...,,\

o'O -(

O

89%

Many methods have been derelq cloalkanones.A clever designincorpo treatment with organocopperreagenLl

Stannylcuprationis analogousto silylcupration.Such a reaction on 1,4-diyn-3-olsis regioselectiveand stereoselective.5

OH (Bu3Sn)2Cu(CN)Lrz

*-r,,o ;: SiMe3

Lijx

\_/

-\

-[ Bu3Sn- \

-----

r

a

\r,""" 83To

Conjugate additions. Methoxyallylcopper reagentsare formed from the allyl ethers via lithiation (with s-Buli) and they give monoenol ethers of 1,6-dicarbonyl compounds on conjugate addition to enones. N-(/-Butoxycarbonyl)dimethylamine is lithiated at one of the N-methyl groups. A route to B-alkylidenepyrrolidinones is developed on further conversion to the cuprate reagentsand subsequentaddition to 2,3-alkadienoic esters.6

Sy2' displacements. 1-Bromo-1 to give l-alkynes. The chirality of rhc entrant group.' I (Note the Zn-based cr4

\^,'\^ I

J |

\-"\-,'\ZU

Br

U

I ^t/

+ l/b

Organocopper reagents

ilr., -:nration is also synthetically

-N-

oAo

(

-tt^1cr1 ----*

c

oAo

-i-F +

-cooet

oAo =(

,roo"/

82o/o

r

-\

) Addition of organocuprates to cross-conjugated enynones leads to the dienones.T Dimethyl sulfide stabilizes the cuprate adduct intermediates when it is employed as a reaction medium.s The conjugate addition-trapping protocol has been applied to preparation of phosphonates. Under CO carbonylation occurs prior to the addition and 1-ketophosphonatesare

LSiMezPh 65%

sr.r.. uprationof allenesand trapping

t

formed.e

rc'..:.lc'neis usedto reactwith enones r. ,.,,pcntanols.a

:,

o

R2cu(cN)Li2 . ^il::, o

tn)''Y errMersi...-\

7h

J

-

*UX-o#, o

Many methods have been developed for the synthesis of chiral 3-substituted cycloalkanones.A clever design incorporatesa neomenthol moiety at the ct-position prior to treatment with organocopperreagents.r0

I

r\

's---*#d

tl

t-

R

-siMe3

.- ,nA 83%

Sp2' displacements. 1-Bromo-1,2-alkadienes undergo transpositional substitution to give l-alkynes. The chirality of the allene moiety determines the configuration of the entrantgroup.rr(Note the Zn-basedcupratereagentscan be usedr2)'

. .ire formed from the allYl ethers comPounds I : ' i : :r' of 1,6-dicarbonYl E_

| .: ,nc of the N-methYl grouPs.A or :.;nher conversionto the cuprate c.: J:.

E f

P

t J

R2Cu(CN)Li2

OH

r -

b

.t reactionon 1,4-diYn-3-olsis

I

t

t a 7

a

80%

89%

)

a a

Ll: i

95%

Organolithim reagents

Olefination.t3 Under the influence of BFr.OEt , acetalsare convertedto 2-substituted 1-alkeneson reactionwith MerSiCH2Cu(PBuj).LiI. Furans and pyrroles.ta Of 2-alkynyl-1.3-dithiolanes, the consecutive reactions with cuprate reagentsand aldehydesor aldimines lead to the five-memberedheterocycles.

Bu2cuLi/ THF P h C H O ;C F 3 C O O H

.J // \

Ph

Ph--\O/^Ph 60Yo



4/

Ni(cod)2 ._ PhcHoirHF

The addition of allyrzinc bromide (allyrmagnesium bromide * znBr) to arkynyilithi_ ums gives rise to gez-bimetalloalkenes. chlorination of the latter species with phso,cl setsup a Fritsch-Buttenberg-Wiechell rearrangement.I8

l(:Lt

N

-

T t Ph^

R f

297

+

M

ZnBr2

Vrnr,.

Phso2cl

(-"' \:

E

!1 i r

, , , r.i' c'therslrfumish amines.Di-

d

rr. - -r.n developed.r2 Their addition rr:^.llF,.OEt.. t . :rrr()\tvrenesin DMF at room ':.rn to the report L on substitution '. :hc :ituationneedsclarification. rL: t r ' ' n of-an enone in the nickelE

coupling reactions. cross-coupling reactions of organozincs with actrvated triflates need the presenceofcuprates.reThose involving teilurium compoundsand cul are catalyzed by Pd(0) comprexes.2'Regioselectivity in the pd(0)-catalyzed coupling of electron-deficient alkenyl halides with ailenic/propargyric zinc reagents depends on the substitutionpatternsof the latter speciestherefore either alkenynoicor alkatrienorcesrers result.''

B u L i , H-' q C t , :Z n B r ,

;

r'n------:-\

\-./

COOET

cooEt

I

66% Ph

B u L i , H g C t 2 iZ n B r 2

R R = Bu 67Yo

t r .

l:

:'

ll:

I

k'. .

.rnd6-acyloxypyran-3-ones, due 't alkynes and dienes generates ,r cxample,alkenylzincsderived r7 ,i I .3-disubstituted 1,3-dienes.

,

4 t: 7

r.t -

-

E

r

P , Ph_-- -

R

iz

R + H

/:\ I

cooEl

F"r \ EIOOc

R

other coupling partners to organozinc reagents incrude heterocyres such as 2methylthiobenzothiazore,22 arkenyl aryr iodonium triflates (arkenyl group transfer fbr syn_ thesisof trisubstitutedarkenes),23 and aryl heteroarylethers.2a Imp.ou"d nicker_cataryzed cross-coupling conditions between orlfta-substituted aryl iodides_nonaflatesand alkyl_ zinc iodidesin solution and in the solid phasehave beendefined.r5

J

Organozinc reagents

e(:""='

* ''n""-'^''cooEt

(\'cooEt

Bu4Nl- 4-fluorostyrene NMP THF

\.r'\-,-.-COOEt 83To

SMe

-ti'^l

+BrZn*Ph

\NASM"

SMe (Ph3P)4Pd> #* rHF^ ll I \N/tA=-'Ph

Alkylatinns. With Pd-catalyst to open all allylic oxabridge diorganozincs intercept the tr-allylpalladium speciesby donating their o-ligands.26

-'("

:'T*

OH

=!d ----$

lve2zn- (dppOPdC12

.']

I

Z'>//V t i l \."^'.-Z

.rl

l

Organozirconium Alkylations.

B0%

' . I

" Bertrand, M.P., Feray, L.. \ousu r r D u a n ,D . - H . ,H u a n g , X. JCR:S, rrKumar,H.M.S., Reddy, B.\,S . t ''Hu, Y, Yu, J., Yang, S., Wang.J r5Ikeda,S., Kondo, K., Sato.\ ('/_ 'nvander Deen,H., Kellogg. R \l . 'tQi, X., Montgomery I.IOC 6l.l rNRezael, H., Yamanoi,S.. Chemtr reLipshutz,8.H., Vivian, R.V. ff, { roDabdoub,M.J., Dabdoub. \lB - \ rrMa, S., Zhang,A., yu, y.. Xra- \A :rAngiolelli, M.8., Casalnuoro. .\.1 ]Hinkle, R.J., Leri, A.C., Dar rd_G lBrigas, A.F., Johnstone, R.A.!* J r5Jensen, A.8., Dohle, W.. Knahrl :('Lautens,M., Renaud, J.-L.. Hrctr rTOhno,H., Toda,A., Oishi. S.. Tar riVarghese,J.P.,Knochel, P..\larcl

reagents. Acylzirconc

ketones.r In the latter ca\e. mechanism.

Elimination. Chiral terminal alleneshave been preparedfrom 2-bromo-2-alken-1-yl mesylatesbearing a protected amino group by treatment with diethylzinc.2TAn alternative way to set up the elimination is by alkylation of alkenylcopperspeciescontaining an ct-sulfonylalkenyl(or sulfinylalkenyt)group with o-iodoalkylzinc reagents.2s The latter protocol allows preparationof trisubstitutedallenes. Ph ..../.--..../,^-..',,. ZrCh R"

R'2cu- lvgBr2 n-----ee,n,

,r,

Ri /:\ R

r-1 ,Cu SOlnlTol

ZnR

R' R

rBoudier, A., Hupe, E., Knochel, P.ACIEE 39,2294 (2000). 2Jackson,R.F.W.,Oates,L.J., Block, M.H. CC l40l (2000). rRyu, I., Ikebe,M., Sonoda,N., Yamamoto,S., Yamamura,G., Komatsu,M. TL 41,5639 (2000). oChemla,F., Hebbe,V., Normant,I.F.TL40,8093 (1999). sMarshall,J.A., Adams, N.D..rOC 64, 5201 (1999). 6Kurono,N., Sugita,K., Takasugi,S., Tokuda,M. f 55, 6097 (1999). 7Lutz,C., Jones,P.,Knochel, P S 312 (1999). nl-entsch,L.M., Wiemer, D.F. JOC 64,5205 (1999). eShibata,T., Morioka, H., Hayase,T., Choji, K., Soai, K. JACS ll8,4'11 (1996). roMillot, N., Piazza,C., Avolio, S., Knochel, P. S 941 (2000).

Under the influenceof ( Ph,p the reactionof alkenylzirconiu Acylations. Alkenylzircm of alkynes readily undergo copl selenium substituents are arz respectively.Alkenyl alkyn;"Ikc carbon monoxide with alkvnr.ho

Organozirconium reagents

z

/\,'cooEl

-

;

\-\--cooEt 83% S'.!e

\,

--\ ..

l.

---\,.Ph

' .:\ndg!- diorganozincsintercept

N.

OH

I --^\/ \i.. -\v

I

1lBertrand,M.P, Feray, L., Nouguier,R., perfetti, p. JOC il,91 g9 (1999). t2Duan,D.-H., Huang, X. JCR(S)26 (1999). lrKumar, H.M.S., Reddy, B.V.S.,Reddy,pT., yadav,I.S. TL 40, 53g7(lggg'). raHu,Y., Yu, J., Yang, S., Wang,J.-X., Yin, y. SC 29,1151.(Iggg). r5Ikeda,S., Kondo, K., Sato,y. CZ 122j (lggg). lovander Deen, H., Kellogg, R.M., Feringa,B.L. OL2,1593 (2000). 'tQi, X., Montgomery, J. JOC @,9310 (tggg). lERezael,H., Yamanoi, S., Chemla,F., Normant, l.F. OL2,4lg (2000). l'Lipshutz, B.H., Vivian, R.V. ZZ 40, 2gi1 0999\. 20Dabdoub,M.J., Dabdoub, V.B., Marino, J.p. TL 41, 433, 437 (ZOO0). 2rMa, S., Zhang,A., yu, y., Xia, W. JOC 65,Z2g7 (ZCf,,O). r2Angiolelli,M.E., Casalnuovo, A.L., Selby,T.p. SZ 905 (2000). rrHinkle, R.J., Leri, A.C., David, G.A., Erwin, W.M. OL2, l52l (Z0OO'). 2aBrigas, A.F., Johnstone,R.A.W. "/CS(p/) 1735 (2000). r5Jensen, A.8., Dohle, W., Knochel, p. T 56,4lg7 e0O0\. 26Lautens, M., Renaud,J.-L., Hiebert,S. JACS 122, lg04 (2000). 27Ohno,H., Toda,A., Oishi, S., Tanaka,T., Takemoto,y., Fujii, N., Ibuka,T. TL 4l,5l3l 2sVarghese, J.P.,Knochel,P, Marek, I. OL Z,2g4g (2000\.

Organozirconium reagents, Alkylations. Acylzirconocenes react with allyl and propargyl halides to give ketones.r In the latter case, allenyl ketones are obtained, as a result of the s"2, mechanism.

300,b -.: .:ird irom 2-bromo-2-alken-1-yl f An alternative r-' . :h,licthylzinc.2T i l . - . . r ) p n c rs p e c i e sc o n t a i n i n ga n -: '.r .,ilrlzinc reagents.28 The latter

ZrCOz

cu*

| t |

\\ - n : /

9'lYo

" * l

tn-^-f.o

/

o

Br

R 61%

(

\ ,nrf,tsu.M. TL 41,5689 (2000)

{ , . l i l i 1 7 r( 1 9 9 6 ) .

,!

iz

t ta :rf

nrt I

"u

*t\y' -

U

R'

a

;f P

'nuff Ph...-,^-,..-1

ZnR

lr i r

:E

cl

J

(2000).

Under the influence of (Ph.1P)aNi, a,ct-difluoro-B,"y-unsaturatedestersare formed from the reaction of alkenylzirconium reagentswith bromodifluoroacetic esters.2 Acylations. Alkenylzirconocene chlorides that are generatedfrom hydrozirconation of alkynes readily undergo copper-catalyzedacylations. Thus, enones containing tin and selenium substituents are available from alkynylstannanes3 and alkynylselenides,a respectively.Alkenyl alkynyl ketones are obtained when the reaction is carried out under carbon monoxide with alkynyliodonium salts.5

Organozirconium reagents

R

SeEt

R

SeEt

CuBr.SlVe2

+

R:SeE1

Cp2Zr(H)Cl +

ZrCoc t

Carbocycles.t8 Either fiu zirconacyclopentanesand alklrr

F N

-

Ph

CI

After hydrozirconation withCp2ZrEtz and reaction with an chloroformic ester,alkynes directly (requiring no catalyst) afford conjugatedesters.6 Heterofunctionalizations. Practically all the substrates are alkenylzirconocene chlorides. They behave well in halogenation,Tphosphorylation,s sulfenylation,e sulfinylation,r0selenenylationrr'r2 and selenoacylation,r3 as well as tellurylation,rr'rawhich gives

H

^-+--\

Ph2Si.

\z}:/

I

ZrCh

: H

rise to the substitutedalkenes. a-Cyanoalkenylation.ts

-il

Lithiated epoxynitriles give 2-cyano-1,3-dieneson reaction

with alkenylzirconocenechlorides.

:.I*

s '{"

*..2.. ,fi

1'"0' r/r

I

*

i-Pr2NLi/ THF

/ BF3.OEI2

:

K

SiMe3

.r'

Phzsi--L.-. ,zrcoz : H

I

Ph---:-Br

Ph2Si. I \--|\/

l

H

I

H

I

):\

'ph

.u.,,r+r+ r-1."-o}zen |----------------------Ph2si. I ll Pn--E

4/,/

H rHanzawa,Y., Narita, K., Taguchi,T. TL 41, 109 (2000). 2Schwaebe,M.K., Mccarthy, J.R.,Whitten, J.P.TL 41,791 (2000). 1Zhon1, P., Xiong, Z.-X., Huang, X. SC 30, 3245 (2000). aSun,A., Huang, X. S 775 (2000). sSun,A., Huang, X. T 55,13201 (1999). 6Takahashi,T., Xi, C., Ura, Y., Nakajima, K. JACS 122,3228 (2O0O). THuang,X., Zhong, P.SC 29,3425 (1999). 8zhong,P, Huang, X., Xiong, Z.-X. 5L721 (1999). eHuang,X., Xu, X.-H., Zheng,W-X. SC 29,2399 (1999). r{)Huang,X., Zhong, P., Guo, M.-P. JOMC 603,249 (20W). "Park, C.P.,Sung,J.W.,Oh, D.Y. Sf 1055 (1999). I2Ma,Y, Huang, X. SC 29,429 (1999). lrzhong, P.,Xiong, Z.-X.,Huang, X. SC30,887 (2000). 'oHuang,X., Liang, C.-G. SC 30, 1737 (ZOOO). rsKasatkin,A.N., Whitby, R.l. TL 41,6201 (2000). 'nKasatkin,A.N., Whitby, R.J. IL 40, 9353 (1999). rTKasatkin,A.N., Whitby, R.J. JACS 121,7039 (1999). rEl-iu,Y., Shen, B., Kotora, M., Takahashi,T. ACIEE 38,949 (1999).

Osmium tetroxide. 13,222-225; 14,233-239; 15,240-241; 16,249-253; 17,236-240; 18, 265-267 ; 19, 24 | -242; 20, 275-27 6 Modifications. A recoverable and reusable catalyst has been prepared from an acrylonitrile-butadiene-styrene polymer and Os04. I Dihydroxylations. By using molecular oxygen to sustain the oxidation, high atomefficiency is attained.2 A new cocatalyst duet is N-methylmorpholine and the flavin analogue1,3-dimethyl-5-ethyl-5, l0-dihydrobenzopteridine-2,4-dione.r An allylic trichloroacetamino group in cycloalkenes directs dihydroxylation with OsOa and quinuclidine N-oxide as the oxidizing system.4An interestingchange in the diastereoselectivityby variation of the oxidant composition has been observed.5

lr

12

i2 :1 :2 , l

i9

;i Pr ', J

302

Osmiumtetroxide NHCOCCt3

r'\ t t

+ osoa+

l

\-,/

NHCOCCt3

NHCOCCI3

+ /t ^ ' , ' ol H

aYot \_-,AOH

NMO / H2O- Me2CO 25' TMEDA lCH2CI2-78'

t l ----/',,OH

2 4 : 76 >95

98Yo 99o/o

Amino-substituted heterocyclesre. sulfonamider3,and primary amides h reactions.raThe untenable siruadoo prepared) as cooxidant in indusrrial sc r5 5,5-dimethylhydantoin.

Aryl 2-alkenoatesshow a revers.( lation.r6

Stereoselectivity in the catalytic dihydroxylation of acyclic allylic alcohols can be enhanced.6 Functional alkanes bearing a 2,3-dihydroxylated pattern are readily obtained, for example, aldehydes from 1-acetoxy-2-alkenyl phenyl sulfonesTand esters from ketene acetals.n I OAc

OAc

r pn-#onc

l

-

+

*

l p6t\,^so2en

"

osoa-NMo

.rrc,;#

1

OH |

OAc |

enl)7^soren . 'oH

NHZ

4 o H 'ro-r^ o V

89%

In situ oxidation of the diols derived from terminal alkenes results in ct-hydroxy carboxylic acids."

Ph.,.a

q AD-mix

Ph98o/o ee) tBuOH - H2O

Aminohydroxylations, Baylis-Hillman alkenes give predominantly syn-diols,r0 whereas the reaction with a,B-unsaturated phsophonates gives rise to cr-hydroxy-paminophosphonates.rr

-r

9" COOMe +

OH

K2OsO2(OH)a

tl

TsN(Cl)Na MeCN - H2O

2"ooMe'oH ( NHTs

rKobayashi,S., Endo, M., Nagayama-S .& 2Dobler,C., Mehltretter, G., Beller. l\l..{O rBergstad,K., Jonsson,S.Y., Beckvall.J -E aBlades,K., Donohoe,T.J., Winter. JJ.G . I 5Donohoe,T.J.,Blades, K., Helliwell. \1.. V 6Donohoe,T.J.,Waring, M.J., Newcombc. TTrost,B.M., Crawley,M.L., tre, C.B .rA EMonenschein, H., Drager,G., Jung..{.. Kr 'Aladro, F.J., Guerra, F.M.. Moreno-Dq-r

OH

* v)Tcoott'l" Ho' 'l NHTs

r0Pringle,W., Shalpless, K.B. ?L 2(). 5 l5 I r ' 'Thomas,A.A., Sharpless, K.B. "/OC 61. tj IrGoossen,L.J., Liu, H., Dress, K.R.. ShlrC rsGontcharov, A.V., Liu, H., Sharpless.K B 'uDemko,2.P.,Bartsch,M., Sharpless.K B r 5 B a r t aN , . S . ,S i d l e r ,D . R . , S o m e r v i l l eK . B (2000). 'nMorgan,A.J., Masse, C.E., Panek.J.S.()l

Osmium trichloride-potassiumferrl Dihydroxylations. An efficienrr couplesandquinuclidine methanesul rEames,J., Mitchell, H.J., Nelson.A.. O'Bn

Osmiumtrichloride-potassiumferricyanide

f'l*.- -uli

NHCOCCI3

^l

\Y,

. -,'\,"oH I t

l

\,/,,,on

,a

: 7 6

Amino-substituted heterocycles(e.g., 2-aminopyrimidine),r2 sodium N-chloro-t-butylsulfonamider3,and primary amides have been developed as a nitrogen source for these reactions.ra The untenable situation in using t-butyl hypochlorite (3 equiv, freshly prepared) as cooxidant in industrial settings is amendedby replacing it with 1,3-dichloroIs 5,5-dimethylhydantoin. Aryl 2-alkenoatesshow a reversed regioselectvity in the asymmetric aminohydroxy-

>95

lation.r6

.rcrclic allYlic alcohols can be

)r

K2OSO2(OH)a

I

(DHo)?-AoN>

a\/-\(o.-r\ il O

.rrt!-rn are readilY obtained, for ullonesr and estersfrom ketene

Fnl

,. \MO + ..,. H2o

|

OAc

en\*so,en

z-NH2/ t-Buocl n-ProHiH2o

I

%Br

tl ; f

r OH

ll

N

H

Z

4Aro)oH o

.

I

?

aYo)-

NHZO

%Br (7

|\ ,,

H 9e|.

1)

89%

r.1l alkenesresults in a-hydroxy

c:"

F-

.,/

F]

COOH

6.

-38% ee)

r-, . irvc predominantly syn-diols,rO o.: 'r.tt.s gives rise to a-hydroxy-p-

_ : loN4e a

a1..-s

Ho

COOMe 'l NHTS

t t

',,-

trl

"2 , .

rKobayashi,S., Endo, M., Nagayama,S. ./ACSl2l, 11229(1999). 2Dobler.C.. Mehltretter.G., Beller. M. ACIEE38,3026 (1999). rBergstad,K., Jonsson,S.Y.,Biickvall, J.-E.../ACSl2l, 10424(1999). aBlades,K., Donohoe,T.J.,Winter, J.J.G.,Stemp,G. TL 41,4701 (2000). sDonohoe,T.J., Blades,K., Helliwell, M., Moore, PR., Winter, J.J.G.,Stemp,G. JOC 64' 2980 ( 1999). 6Donohoe,T.J., Waring, M.J., Newcombe, N.J. SL 149 (2000)TTrost,B.M., Crawley,M.L., Lee, C.B. ./ACS122,6120 (2000). sMonenschein,H., Drager,G., Jung,A., Kirschning,A. CEJ 5,2270 (1999). eAladro, F.J., Guena, F.M., Moreno-Dorado,F.J.,Bustamante,J.M., Jorge, 2.D., Massanet'G.M. TL41,3209 (2000\. rOPringle, W., Sharpless,K.B. 7a 40, 5151 ( 1999). llThomas,A.A., Sharpless,K.B. JOC 64,8379 (1999). l2Goossen,L.J., Liu, H., Dress,K.R., Sharpless,K.B. ACIEE 38, 1080( 1999). l3Gontcharov,A.V., Liu, H., Sharpless,K.B. OLl,783 (1999). raDemko,Z.P, Bartsch,M., Sharpless,K.B. OL2,2221 (2000). rsBarta,N.S., Sidler,D.R., Somerville,K.B., Weissman,S.A., Larsen,R.D., Reider,P-J.OL 2' 2821 (2000). r6Morgan,A.J., Masse,C.8., Panek,J.S.OL 1, 1949 (1999)'

9H

, l

Osmium trichloride-potassiumferricyanide. Dihydroxylations. An efficient dihydroxylationprotocol employs theseoxidant /-butanol.r in aqueous methanesulfonamide couplesandquinuclidine rEames,J., Mitchell, H.J., Nelson,A., O'Brien, P, Wanen, S., Wyaa, P.JCS(PI ) 1095( 1999).

'g ts i P

t J

304

l-Oxo'2,2'6,6't$ramethylpiperidine chloride

-268; 19' 243;20,277 Oxalyl chloride. 17,241-242;18,26'l the following Diaryl kctones.t A Friedel-crafts acylationmethod is shown in eouation:

rTakata,T., Tsujino,Y., Nr\an.

Oxygen. 18. 268-269: 19. . Epoxidations. In thc hydrogenperoxidegenemk

without a metal catal) sr hydroxyphthalimide, Mol O Oxidations. Benzllrc the presenceof many differ

ctco-cocl i Alc13 PhOMe / CH2C|2

OsOais needed).rRu-on-h under fluorous biphasic coo A remarkableeffect of q

CJ :I::

:-r

s-!^ ,.{

catalyzedbenzylicoxidatro

rTaber,D.F.,Sethuraman, M.R. .IOC65' 254(2000)' S-(1-Oxido-2'pyridyl)- 1,1,3,3-tetramethyluronium salts' temperature by a Amides.t carboxylic acids are converted to amides at room tetrafluouronium combination of NH4CI and i-Pr2NEt in DMF using the substituted roborate or hexafluorophospahate(1) as condensingagent'

..n

Aromatic aldehydes thc liquid underthe influence< tcristic of the VOCIr-catalr; honyl compounds).e

B-Ketoesters are oxidrz rnanganese(Il) acetate)"or r c.p-unsaturatedphosphoru

PdCl, and isopentylnitnte trons,that is. 02, Fe;O,.and Oxidation of organonr cleavagewith Zn-HOAc cr the oxidative captureof a p rnd the reductiveDath$a\r

*!!M", ,f\ x il t tl \ fr'As^ Ntt't", o I

(1)

rBailen.M.A.,Chinchilla, D'J',Najera,C'TL4l'9809 (2000)' R.,Dodsworth,

| -Oxo-2,2,6,6-tetramethylpiperidine chloride' pAminoxychlorides'|Thetitlecompoundbehavesasanelectrophilicagent used to form the chlorotoward activated alkenes. Allied oxoammonium salts can be

o l i l

o'"\'/ :

hydrin derivatives.

r-\ t

;\;{

t

-

t

l

cr * \*

R = Ph, OEt,.

.*;

I o) I R^cl

Alkyl halides and tosll CuCl-Kieseelguhr as catalv Sulfoxidation of saturarc

Oxygen rTakata,T., Tsujino, Y., Nakanishi, S., Nakamura, K., Yoshida, E. CL937 (199q.

r

- 'no*n in the following Oxygen. 18, 268-269; 19, 243-244; 20, 277-27 9 Epoxi^dations. In the presence of perfluoroacetone and N-hydroxyphthalimide, hydrogen peroxide generatedin situ from oxygen and l-phenylethanol epoxidizes alkenes without a metal catalyst,t although there is also an alternative2 in using Nhydroxyphthalimide, Mo(CO)6, and Co(OAc)2.

i- ' ' ''^'o M "

Oxidations. Benzylic alcohols undergo aerial oxidation to aromatic aldehydes in the presenceof many different catalysts: OsOo/CuCl-pyridine (for benzylic alcohols only OsOais needed),3Ru-on-hydroxyapatite,4hydrotalcite-supportedPd(ID,5 and CuBr'SMe, under fl uorous biphasic conditions.6

5. k'

.rl IOOfiI

temperature bY a

tetrafluo: . . . ^ - t i t u t euronium d

A remarkable effect of quaternary ammonium bromides in the N-hydroxyphthalimidecatalyzedbenzylic oxidation has been noted.T Aromatic aldehydesthemselvesare oxidizedto acid 8 by molecularoxygen in ionic liquid under the influence of Ni(acac)2. Excellent yields and mild conditions are charac:

lf

teristic of the VOClj-catalyzed oxidation of ct-hydroxy carbonyl compounds (to the dicarbonyl compounds).Y

t ) ' . J

B-Ketoesters are oxidized at the a-position with oxygen in the presence of either manganese(Il)acetatel0or cobalt(Il) chloride.rrCyclic allyl phosphonates give 1-acetoxy o,B-unsaturatedphosphonateswhen they are exposedto oxygen in HOAc containing PdCl2and isopentyl nitrite.12Tertiary amine oxides are formed undercooxidation conditions, that is, 02, Fe2Oj,and isovaleraldehyde.r3 Oxidation of organomercury compounds via formation of TEMPO derivatives and cleavagewith Zn-HOAc completesthe functionalizationof alkenes.laWithout TEMPO the oxidative capture of a primary radical generatedfrom organomercurial is inefficient, and the reductivepathway(lossof functionality)becomescompetitive.

,1000). O i l

Itr

.r\ an electrophilic agent used to form the chloro-

l l

o'\-\ : 02 - NaBHaTEMPO/ DMF ZnlHOAC-H2O 100.

,-_\ '-*{ I

o-l R^cl

50%

Alkyl halides and tosylatesare oxidized to carbonyl compoundsby oxygen using CuCl-Kieseelguhras catalyst.r5 Sulfoxidationof saturatedhydrocarbons'6with O2-SO2is catalyzedby VO(acac)2.

a

a

t

7

"j

1/a E

I

i

fr t

P ,

Oxygen

cooH I

.r\ t f

rF4 /,./\./

I

cooH 02 - SO2 VO(acac)2 / HOAC

SO3H

A catalyst prepared cleavageof enaminestc A formal hydrauo PhSiHj-Mn(dpm). in rs

oxidation of unsaturated compounds. Methyl ketonesare producedfrom l-alkenes using molecular oxygen as oxidant [catalyst: Pd(OAc)2-pyridine].r7 on the other hand' methyl 3,3-dimethoxypropanoateis formed when eth1il acrylate is oxidized on activated and Pd(oAc)2 in acidic ethanol.r8Treatmentof carbon-supportedmolybdovanadophosphate enoneswith LiAlH4 under dry oxygen gives l,3-diols.re

Cl :T:

Ph

;-t-

)

7.

02 - LiArHa + THF

Ph \_nu ./ \

roH ,P hroH

Ph

90% (syn : anti 1 ;1)

.,{

Oxidation of phc dihydroxybiaryls in the1 a-Hydroxy-ybut-m combinedin an oxidat phthalimide, Co(acao,;

. i

Cyclization of diarylamines are also effected although an analogous process for the and Sn(OAc)2.2() lessreactivediphenytetherrequiresPd(OCOCFT)2 o-benzoquinone,which forms Dielsphenol into of Tyrosinaseinitiates conversion other cooxidants in the oxidative instead of of oxygen Alder adducts.2tEmployment ether and alkenyl side chain is silyl enol a cyclization of compounds containing

Go"

desirable.22

o

OH

02 / Tyrosinase

\o=, 'A. v

cHct3

ov rl-t>

I oEt

Acetyladamantancs. of adamantanewhen thc IO1-Co(OAc),in HOAc.

70% OSiMe2(t-Bu)

6.Y

02 / Me2SO Pd(OAc)2

BlYo

Oxygen , _:-l

-1-so,n

A catalyst prepared by encapsulation of cucl, in zeolite X is useful for oxidative cleavageof enaminesto afford amides.23 A formal hydration of enones and dienones is achieved by reactron with PhSiHvMn(dpm)i in isopropanol under oxygen followed by work up with (Eto)3p.24

I i.- ::c. are producedfrom l-alkenes ;-rndine].r-On the other hand. Ais oxidized on activated .,-^latc li. ethanol.rsTreatmentof .:r .rcidic )-r-

-

iox

[.4n(dpm)3

r1.'"\-\ t l

n

ii

-t--f

PhsiH3

51%

,, F l -

r

1: 1 )

oxidation of phenors. phenors including 2-naphthol are oxidized to 2,2,dihydroxybiarylsin the presenceofVO(acac)2.25 Hydroquinonesgive quinones.26 a-Hydroxy-y-butyroractones.zi secondary alcohors and meihyr acrylate are combined in an oxidative fashion when they are subject to oxidation with N-hydroxy_ phthalimide,Co(acac)j,and Co(OAc)2 under oxygen.

a

I

, ) t

_ t

a

It: .::r ,rn analogousProcessfor the lr : .': O.\c)r.10 , -.-'l,lquinone,which forms Diels':r..r cooxidants in the oxidative r - :rc'r and alkenYl side chain is I

=

E

O2 Co(OAc)2 Co(acac)3

2\-4

I

\,,\

ll

s

P

o NoH NrecN

t 83%

Acetyladamantanes.2s Acetyl groups are introduced into the bridgehead positions of adamantanewhen the hydrocarbon and biacetyl are submitted to oxidation conditions [O2-Co(OAc)2in HOAc, 60.i.

47Yo

20yo

l"

Orygen

Alkylation of carbonyl compounds and derivatives. The O2lCo(OAc)2-Mn(OAc)2 Acetals also add system is useful to accomplish ct-alkylation of ketones with 1-alkenes.2e to acrylic esters under 02 in the presence of catalytic amounts of Co(OAc)2 and N-hydroxyphthalimide to afford ct-hydroxy-"y-oxoester acetals.30The adducts of methyl vinyl ketone suffer oxidative degradationin situ.

O..rO R^H

+ Z\COOMe

Oxygen,singlet.13,22g-229:ll. 2a 269-270;19,244 Allylic alcohols. Accesslo r. photooxygenation with reductir.e * trj Alkoxydioxines.2 Dienolerhen

02/ co(oAc)2 -1--l- On --------l* O..rO R"-'-'/\coptr,le A ,-.4 I

\,-\

ll

,aR )

NoH

l-oR' l

o

*

Cleavage of 1,3-oxathiolanes.rt

F FI

F--rr

(J I

};*.

Carbonyl

compounds are regenerated on heating

2-substituted oxathiolanes with VOCIr in CF.CH2OH under 02. rlwahama, T., Sakaguchi,S., Ishii, Y. H 52, 693 (2000). 2Iwahama,T., Hatta, G., Sakaguchi,S., Ishii, Y. CC 163 (2000). 3Coleman,K.S., Coppe,M., Thomas,C., Osbom, J.A.TL40,3723 (1999). aYamaguchi,K., Mori, K., Mizugaki, T., Ebitani, K., Kaneda, K. JACS 122,'7144 (2000). sNishimura,T., Kakiuchi, N., Inoue, M., Uemura,S. CC 1245 (2000). bBetzmeier,B., Cavazzini, M., Quici, S., Knochel, P. TL 41, 4343 (2000). TMatsunaka,K., Iwahama, T., Sakaguchi, S., Ishii, Y. TL 40,2165 (1999). bHowarth, J. TL 41, 662'7(2000). eKirihara, M., Ochiai, Y., Takizawa, S., Takahata,H., Nemoto, H. CC 1387 (1999). roChristoffers. J. JOC U.7668 (1999). IIBaucherel,X., Levoirier,8., Uziel, J., Juge,S. TL 41, 1385(2000). I2Attolini, M., Peiffer, G., Maffei, M. I56, 2693 (2000). r3Wang,F., Zhang,H., Song,G., Lu, X. SC 29, 11 (1999). r a H a y e sP, , S u t h e r s8, . D . , K i t c h i n g ,W . T L 4 l , 6 1 7 5 ( 2 0 0 0 ) . rsHashemi,M.M., Beni, Y.A . JCR(S) 434 (1999). 16lshii,Y., Matsunaka, K., Sakaguchi, S. ,/ACS 122,'7390 (2OO0). rTNishimura,T., Kakiuchi, N., Onoue,T., Ohe, K., Uemura,S. JCS(P1) 1915 (2000). r8Kishi,A., Sakaguchi,S., Ishii, Y. oL2,523 (2000). 'ecsaL:),,A.G., Maximo, N., Plumet, J., Ramila, A. TL 40,6485 (1999). 20Hagelin,H., Oslob,J.D., Akermark, B. CEJ 5,2413 (1999). 2 r M u l l e r ,G . H . , I - a n g ,A . , S e i t h e lD , . R . ,W a l d m a n n , H .C E J 4 , 2 5 1 3 ( 1 9 9 8 ) . 22Toyota,M., Odashima, T., Wada, T., Ihara, M. JACS 122,9036 (2O0O). z3Bbitani,K., Nagashima,K., Mizugaki, T., Kaneda,K. CC 869 (2000). 2aMagnus,P., Payne,A.H., Waring, M.J., Scott, D.A., Lynch, V. TL 41,9725 (2000). 2sHwang,D.-R., Chen, C.-P.,Uang, B.-J. CC 1207(1999). 26Hwang,D.-R., Chen, C.-P.,Wang, S.-K., Uang, B.-J. SL77 (1999). 2?Iwahama,T., Sakaguchi, S., Ishii, Y. CC 613 (2000). 28Kishi,A., Kato, S., Sakaguchi,S., Ishii, Y. CC 1421 (1999). 2elwahama,T.,Sakaguchi,S., Ishii,Y. CC2317 (2000). 30Hirano,K., Iwahama, T., Sakaguchi, S., Ishii, Y. CC 245'7(2ON). 3rKirihara,M., Ochiai,Y, Arai, N., Takizawa,S., Momose,T., Nemoto, H. TL 40,9055 (1999).

Oxidative cleavage,t The .\.-an undergoring fission to afford ranlr c'xcludedfrom the reactionmedia.rhc the presenceof Me.SiCN).

(\'* \:'/

o: -'€-{

tr--

t)

\b3\

Helesbeux, J.-J.,Guilet,D., Seraphrn. D. ':000). Dussault, P.H.,Han,e., Sloss,D.G..Srrnu C()cquer. G.. Ferroud. C..Guy.n. f SO.:C-:

Oxygen,singlet

ldre s. The O2lCo(OAc)z-Mn(OAc)z Acetals also add 96.;. $ rth l-alkenes.2e Co(OAc)z and of amounts r::.:.rllc of methyl adducts The rcetals.ro ..:J:

^-1 g* I{A"oo""

c

Oxygen,singlet.13,228-229; 14, 247; 15, 243; 16,257-258; 17,251-253; 18, 269-270:19.244 Allylic alcohols. Accessto o-(2-hydroxy-3-methylbut-3-enyl)phenols is through photooxygenation with reductiveworkup.I Alkoxydioxines.2 Dienolethersform suchcycloadducts with singletoxygen.

tr*

'

g-oY* ...............'.........'..'.,.'"............-...............*

( -oR'

02 | cH2ct2

tetraphenylporphyrin

.

*-oD R = Bu

630A

,, heating c " :",unds are regeneratedon ,()li ,indcrO1.

3 ,,,' It {r rll-l (1999)' (2000)' b;, :, K JACS122,'7144 '( -ir l(DO). .l rt :rrl (2000). r : . l l r - 1 6 5( 1 9 9 9 ) . I l C C 1 3 8 7( 1 9 9 9 ) '

\r'.

. :.. lrn0).

Oxidative cleavage.3 The N-arylamino derivatives of piperidine and pynolidine undergo ring fission to afford (aryl)diazenylalkanals or their acetals. When water is excludedfrom the reactionmedia, the o-carbon can be functionalized(e.g., cyanationin the presenceof MejSiCN).

_

r r r r

r. .

. - / ( ' s / P / l)9 l 5 ( 2 0 0 0 ) .

{Jr '.1\i ( 1999). ,: r 15l3(1998)' ; l :: '' ' 16(2000). .r,9 i2000). ; r . \ TL41.9725(2O0O)' (+,' . -, ..

1999).

I

0 ":.6

.

l(X)O). I .\emoto,H'TL40,9055(1999)'

a -

, a

NH

\.... ( )

02 / methyleneblue MeCN - H2O

-

l-v* \-/

a

\\ *-\

*\c"o

7SYo

F

F a

It

7

) ),.

a

rHelesbeux,J.-J., Guilet, D., Seraphin, D., Duval, O., Richomme, P., Bruneton, J. TL 41,4559 (2000). rDussault,PH., Han, D.J. T 55,11437 (1999). Q., Sloss,D.G., Symonsbergen, 'Cocquet, G., Ferroud,C., Guy, A. f 56,2975 (2OOO).

I f

P , I

I

|

/---r

o{r-p

Palladacycles for Many palladacycles,besidesthosederivedfrom bidenatephosphines'are available P'N-"BCligated N'C-' N,N-, O,N-, include varieties These catalyzingorganic reactions. as well as species.In the following, a selectionof palladacyclecatalystsbearing such presented' are diphosphines moreexoticbidentate

r!_p6_eso( ( | \_,/

--1..,-f-Ta

o v (2)

Reductions.Acenaphthoquinonediimineligatedpalladiumcomplexesanda of polymer-boundpalladaisoindolinehave tbund use as catalystsfor semihydrogenation nitro (including the compounds unsaturated common alkynesl and reduction of several group),2respectivelY.

E -T', =t:

Couplingreactions.Various(Heck'stille,suzuki,sonogashira'andUllmann) r coupling reactionsare mediatedby a stablepalladacycle1

activespecies.ll Sulfur-containingpallad< show excellent utility in 0r I ,850,000)|2 and Suzuki coup

tt,

Ph \ nr.r /AN'""

t;., {rli

l-\pi-t \ . / \_/

r ct_

Other stableand efficienrr zole-basedpalladacycles."Th that palladacyclesderived in

Aromatic ketones are a.l RCOS(CHr)4X.Palladac.v-c!

l Iz

(1) that is Accelerationof the intramolecularcoupling of phenol and aryl halide moieties etfectedwith a 4C-palladacycleby a baseis realized'ao-Aminophenyldiphenylphosphine is a ligand that forms effectivePd complexesfbr the Heck reaction's

.,\ O -"4*"i

- z+d3!"lfi-:::^]J"' ^.4 \/-''\o16^[# '.oAfo)

Displacements. A ratho nucleophileshas been reponed

BjYo

in contrastto other Note that palladacyclestypified by 2 arepoisonedby 1,4-dienes,6 pd(0) catalystsystems.Accordingly,the Heck reactioncannotemploy thesecatalysts.on (aryl the other hand, 3 has a high thermal stability and broad scope of application (3 examples, 4 is also a highly activecatalystfor the Heck reaction couplings).TComplex 95-100%)." 310

t N"'

*9

*r* \

0

Palladacycles

? _ ---.-b---rl

/o-t)\.8' 11 tr

-,,^^-. ,,^,d- ,-(o\ tot'^"''-''l

I ll '-Pr2NEti DN'4F\-"\Z\OV" 5o'

ctr

MeO

I

61%

afford 1,3-transAllylic N-tosylcarbamates (from allylic alcohols and TsN{:O) decarboxylation, DMF, in Pd(OAc)2-LiBr with posed allylic N-tosylamines via ionization - J "

^*, -r'ul -.:rrl

.

,.1 ,

and substitution.32 Silyl esters are formed by oxidative functionalization of hydrosilanes with Pd(oAc), and carboxylic acids.rr Bisphosphinesare oxidized to the monooxides,3athus bidentate phosphorusligands of mixed oxidation statesare readily accessible.

Conjugate addition. T}r is catalyzed by Pd(OAc)1. Fr lidinones)that bear a 4-oxoalhl't

availableby a Pd-catalyzedrntrr R

I+*

04.

o

dl

ph2p.*r,

,;i

pph2

L rn

- NaoH Pd(oAc)1 ph2p-F-U''i'Ph2 BTCH2CH2BT

L rn

clcH2cH2cl

IN

Hydroarylation. Catalytic Ar-H bond activation is observedwith a complexed Pd speciesand the delivery of the aryl group to alkenesshowssome asymmetricinduction'ts activation by For heterocycles such as methylfuran, pyrroles, and indoles, Ar-H pd(OAc)2is adequatein their addition to 2-alkynoicestersin a rrans-fashion.16

Pd(oAc)z- -): Ar-H

+ R:cooa,

c'zctz

Ai

t"oor,

Many arenes are converted to carboxylic acids in good yields pressure of co under the influence of Pd(oAc), but without under atmospheric phosphine ligands. Potassium peroxysulfate and trifluoroacetic acid tue present in the carboxylation.sl

reaction media. Rearrangement-coupling.ls This effective synthetic process involving an alkene and allylic alcohol in juxtapositionis applicableto the synthesisof (+)-equilenin.Solvent determinesthe diastereoselectivity.

t

\

,NH'\

rs

'r:

\r

h,

rBlettner,C.G., Konig, W.A.. Srco rXia, M., Chen,Z. SC 30, 63 (2U rZhang,C., Trudell, M.L. TL 11.1 lCatellani, M., Moni, 8.. Minan. t 5Catellani,M., Cugini, F. f 55.65{ 6xia, M., Chen,Z. SC 29,2457 rl\ tDarses, Michaud, S., G., Gencr.J. EColas,C., Goeldner,M.E JOC ll. 'Brunner, H., Le Cousturier de Ccr "'Arcadi, A., Chiarini, M., Marirrlt "Gron, L.U., Tinsley,A.S. TL 4. = rrHirabayashi,K., Ando, J., Kas'ash rrHirabayashi,K., Ando, J.. Nishh HMatoba,K., Motofusa,S., Cho. C r5Liang,Y., Luo, S., Liu, C., \*'u. X. 'nQuan,L.G., Gevorgyan, V.. \'anp r r M a n d a lA , . B . , L e e ,G . - H . .L i u . . t ' [Larock, R.C., Doty, M.J., Han. X. reOhe,T., Tanaka,T., Kuroda. Il . ( roJia,C., Lu, W., Oyamada.J.. Krt (2000);Jia, C., Piao, D., Krtamun rrSakurai,Y., Sakaguchi,S., Ishl. t r:Ali, B.E., El-Ghanam,A., Fenouh :rRoesch,K.R., Larock, R.C. Ot l. rlHayashi, M., Yamada, K., Anhrr. :sNishimura, T., Onoue, T., Ohc. lL. roNishimura. T.. Ohe. K.. Uemura- !

PalladiumflI) acetate

r.-

1,-haloarylethers that bear a Pd(OAc)z

MeO HMPA- THF ctcH2cH2ct

OMe

27 100

73 0

61Yo afford l,3-trans:-.r f.N{:O) t-rBr in DMF, decarboxYlation.

A-

lu: : ,\l hydrosilaneswith Pd(OAc), tl-.-. ^rdcntatephosphorusligandsof

Conjugate addition. The addition of MerSiCN to enones derivatives of glycals3e is catalyzed by Pd(oAc)2. Five-membered azacycles (lactams, imidazolinones, oxazolidinones) that bear a 4-oxoalkylidene group adjacent to the nuclear nitrogen atom are readily availableby a Pd-catalyzedintramolecularaddition and conjugateaddition tandem.ao t

R

I a

X_VR

..4N ,NH'\ Ts )-, t1

t

, I

IS

R

'

I ,

J

n

.-:

'bpn"

\r

r, : :. ()hservedwith a complexedPd \: .\. \ome asymmetricinduction.ri j:r.: :ndoles. Ar-H activation b;c-'.:. ln a lrans-fashion.36

, '. -

R\

Ar

'cooet

: ..rrboxylic acids in good Yields n:: ...':r.!- of Pd(OAc)2 but without 'r::.. ,:,,eccticacid are present in the ir.::r-:r! processinvolving an alkene hr . .:rthesisof (+)-equilenin.Solvent

'Blettner,C.G., Konig, WA., Stenzel,W., Schotten,T. JOC 64,3885 (1999). 2xia, M., Chen,Z. SC 30. 63 (2000). 3zhang, C., Trudell, M.L. rL 41,595 (2000). aCatellani, M., Motti, E., Minari, M. CC 151.(2000). 5Catellani,M., Cugini, F. 255,6595 (1999). 6xia, M., Chen,Z. SC 29,245i (1999\. TDarses,S., Michaud, G., Genet,I.-P. EJOC 1875 (1999). 8Colas,C., Goeldner, M.E JOC 1357 (1999). 'Brunner, H., Le Cousturier de Courcy,N., Genet,J.-P.TL 40,4815 (1999). I0Arcadi,A., Chiarini, M., Marinelli, F., Berente,Z.,KollalL. OL2,69 (2000). " Gron, L.U., Tinsley,A.S. TL 40,227 (1999). r2Hirabayashi,K.,Ando,J.,Kawashima,J.,Nishihara,Y.,Mori,A.,Hiyama,T. BCSJ73,1409(2000). IrHirabayashi,K., Ando, J., Nishihara, Y., Mori, A., Hiyama, T. SLgg (19gg). raMatoba,K., Motofusa,S., Cho, C.S., Ohe, K., Uemura,S. JOMC 574,3 (1999). r5l-iang,Y., Luo, S., Liu, C., Wu, X., Ma, Y. 256, 296l (2000). r6Quan,L.G., Gevorgyan, V., Yamamoto, Y. JACS 121,3545 (lggg). rTMandal,A.B., Lee, G.-H., Liu, Y.-H., Peng,S.-M., Leung, M.-K. JOC 65,332 (2N0). rsl-arock,R.C., Doty, M.J., Han, X. JOC 64,8i.70 (1ggg). IeOhe,T., Tanaka,T., Kuroda, M., Cho, C.S., Ohe, K., Uemura,S. BCSJ 72,1851 (1999). :OJia,C., Lu, W., Oyamada, J., Kitamura, T., Matsuda, K., Irie, M., Fujiwara, y. JACS 122,7252 (2000); Jia, C., Piao, D., Kitamura, T., Fujiwara, Y. JOC 65,'1.516(2000); :rSakurai,Y., Sakaguchi, S., Ishii, Y. TL 40,1701 (1999). 22Ali, B.8., El-Ghanam, A., Fettouhi, M., Tijani, J. TL 41,5761 (2000). :3Roesch,K.R., Larock, R.C. Ot 1, 1551 (1999). raHayashi,M., Yamada,K., Arikita, O. 255, 8331 (1999). 2sNishimura,T., Onoue,T., Ohe, K., Uemura,S. JOC 64,6750 (lggg). r6Nishimura, T., Ohe, K., Uemura, S. JACS 121,2645 Ogg9i.

t

-

:

c t, ca t ,a I

Palladium(Il)

acetate-phase-transfer

catalysl

2?Xia, M., Chen,Z. JCR(S) 400 (1999). 2sBumagin,N.A., Korolev, D.N. fZ 40, 3057 (1999). 2eMino, T., Hirota, T., Fujita, N., Yamashita,M.S 2024 (1999). 3oJonasson, C., Karstens,W.F.J.,Hiemstra,H., Blickvall, l.E. TL 41,1619 (2000). 3rEdvardsen,K.R., Benneche,T., Tius, M.A,. JOC 65,3085 (2000). 32lei, A., Lu-X. OL2,2357 (2000). 33chauhan,M., Chauhan,B.PS., Boudjouk,P. OL2,1027 (2000). 3aGrushin,V.V../ACS121, 5831 (1999). 35Mikami,K., Hatano,M., Terada,M. CZ 55 (1999). i6lu, W, Jia, C., Kitamura, T., Fujiwara, Y. OL2,292'7 (2000). 37Lu,W., Yamaoka,Y., Taniguchi, Y., Kitamura, T., Takaki, K., Fujiwara, Y. JOMC 580,290 (1999). 38Nemoto,H., Yoshida, M., Fukumoto, K., Ihara, M. TL 40,9O'7(1999). 3eHayashi,M., Kawabata, H., Shimono, S., Kakehi, A. TL 41,2591 (2000). ml-ei, A., Lu,X.OL2,2699 (2W0).

Palladium(Il) acetate{cr 247-248; 16, 264-268: t7, Aryl coupling reacti contains Pd(OAc)1, KF. catalyst to date is the co which is effective to ccru mol%o)yet showing turnor in good yields.

Allylatinns. Allylauc presenceof Pd(OAc):_ph.I leading to bridged ring srr active methylenecomprrund

\ J '

--T-'lfl ,;

=! -!

Palladium(Il) acetate-phase-transfer catalyst.20, 284-286 Heck reaction Heck reaction of 2,5-dimethoxy-2,5-dihydrofuran leads to Barylbutenolides. It only requiresa reductionstepto furnish3-arylfurans.r

r^

.;l ..arI

h\6\

\z\, i *$t 'i

Pd(oAc)2-R4Nct

* M"o-/toAou" -A".J: -

>\ ->-, \

/

\oAo

,i 66% An aryl group can be introduced to a substituted B-posittion of an a,B-unsaturated ketone2 or other electron-deficient alkenesl by the Heck reaction in the presence of a phase-transfercatalyst. Deallylation.a Water-insoluble allyl substrates are cleaved by Pd(OAc)2 using water-soluble phosphine ligand and per(2,6-di-O-nethyl)-B-cyclodextrin. Unsymmetrical biaryls. Coupling of ArI with Ar'Br proceedswith good selectivity employing electron-deficient Ar'Br under specified conditions: A catalytic system composedof Pd(OAc)2,Bu+NBr,iPrrNEt in refluxingp-xylene.s A simple procedurefor Suzuki coupling involves heating the substrateswith Pd(OAc)1 and KsPOa in DMF. A beneficial additive is BuaNBr.6 When (EtS)2PdCl, is used. the quaternaryammonium salt is not required. rTaniguchi, T., Nagata,H., Kanada,R.M.,Kadota,K., Takeuchi,M., Ogasawara, K. H 52,67 (2000). 2xia,M., Chen,Z.SC30,l28l (2000). rGurtler,C., Buchwald,S.L. CEl 5, 3107(1999). 4Widehem, R., Lacroix,T., Bricout,H., Monflier,E. 5L722(2000). 5Hassan, J.,Hathroubi, C.,Gozzi,C.,Lemaire,M.TL4l,8791 (2000). 6Zim,D' Monteiro,A.L.,Dupont,J. TL 41,8199(2000).

L--o

Arylamines undergo .\.contains titanium tefai sop( the amino group is unhindcr Homoallyl alcohok. homoallylic alcoholsin rhc three-component condensa

moiety from allene and ant indium. A relayed processd intricacyof sucha reaclion

-$"ro.

:

Palladium(Il) acetate-tertiary phosphine

1s... j : . ' r ' { 1 . 1 6 1 9( 2 0 0 0 ) . -'rtt. F' !- -.,,,

Palladium(Il) acetatFtertiary phosphine. t3,91, 233-234; 14, 249, 250_253: lS, 247-248; 16, 264-268; 17, 259-269 ; 18, 277 -281; 19, 252-256; 20, 286-289 Aryl coupling reactions, A highly active catalytic system for Suzuki coupling contains Pd(oAc)2, KF, and di-r-butyl-2-biphenylphosphine,t but the most efficient catalyst to date is the combination of Pd(oAc)2 and bis(l-adamantyl)butylphosphine, which is effective to couple deactivated Arcl on very low pd loading (down to 0.001 molvo) yet showing turnover number in the 10,000-20,000 range.2products are obtained in good yields.

t: ,. rr r tjujrwara,Y. JOMC 580' 290 (1999)' +r . r1999). t'i {l :591 (2000).

Allylations. Allylation of enamineswith l-allylbenzotriazoles3is accomplishedin the presenceof Pd(OAc)2-Ph.P andZnBr2. The stepwisetwofold allylation of cycloalkanones leading to bridged ring systemsauses 2-methylene-1,3-propylenediacetate.Allylation of active methylenecompoundswith allylic alcohols is promoted by triethylborane.5

1

20. l.fl86

OAc Pd(oAc)2- Ph3P

\

leads to Brn.:: ,\\ -2.5-dihydrofuran t(':..:nl\h3-arylfurans.r

|\\/

/-v

MecN a0

I

\

rTf\-

l=\Z_/ rv

OAc

r:

tr

> ..-

. RINCI

lr,1F 80' -3-

66% ir-:,.r 1,i-posittionof an ct,B-unsaturated r:.- llc'ck reaction in the presenceof a lr:r-'. ilrc cleaved by Pd(OAc)2 using -r:. : :rr I r-P-cyclodextrin' r::: \r Br proceedswith good selectivit)'

--_ trn0). L at .-.rl r1000). t

)

t I

77%

Arylamines undergo N-allylation with allylic alcohols.6 The reaction system also contains titanium tetraisopropoxideand molecular sieves. Some dialkylation occurs when the amino group is unhindered. Homoallyl alcohols. Benzaldehyde reacts with various allylic alcohols to give homoallylic alcohols in the Pd-catalyzed reaction that is promoted by triethylborane.TA three-componentcondensationthat producesarylated homoallyl alcohols derives the allyl moiety from allene and aryl iodides.sThis Pd-catalyzedreaction is mediated by metallic indium. A relayed process that forms an isochromane systemeillustrates the power and intricacyof sucha reaction.

-S.no.-c-*l.ph

In - Pd(OAc)2

tq\,

c..: r.i conditions: A catalytic system | u . . . : :i.t - r y l e n e . 5 lr:. ::tating the substrateswith Pd(OAc); ; fi ...\Br.h When (EtS)2PdCl2is usedK. H 52'67 (2000)' lr. - .-hr.\1.,Ogasawara,

Ia

/--

Ph

l-\ (,

\:./

\F-l ' .

\ - v!

ph

-

+ :Q:

* H< ' o

OH

In - Pd(OAc)2

tq\, 52To

J

J

(

s

,.

a

Palladium(Il)acetatFtertiaryphosphine

322

Cyclizations.lnacatalyticprocess2.aryl-3-alkenylindolesalegenefatedfrom cyclization reactions of enynes and dienynes aldimines derived fiom o-alkynylanilines.t0 in the presenceof aryl iodidesr2to participate under reductive conditions (HCOOH)II or in a coupling Processare useful'

or\

o )---B o r rn - N

+r-ph+

-\_

\

|

pd(oAc)2 - ' B n - N>Y

v

HNJ

|

.&'

)-rn I

a)

\-12\

Ph3PiNIecN

(--("'* .yorf

Y*71o/o

ir.

x,i TI =[ 't:r

Cyclizationthataccompaniescouplingefficientlydeliversa.benzylidene-1-lactones " from homopropargylic chloroformates''

Triarylphosphines. .t bromides or triflates * ith Pt groupslTsuch as a ketoneart rE accessible.

oTf

R

;: -rll

NaBH4-Pd(OAc)2

>

x-,}_ -T,

}> o l -).\..R'

Ph,Pi rHF

\

u I o P h

r-- [l

J

'i ,rl leads to dihydropyran derivattves' An alkyne/5-hydroxy-2-pentynoic ester coupling ethyl 6-hydroxy-2-hexynoate proceedsin Formation of the homologoo' h"t"'otytle from Pd(OCOCFTI:''a two stages,the secondstageis promotedby

*

R--

/-P)^

HO

Pd(OAc)2 / PhH

OMe

J

o \ 'T

):\

r,/1

l-

'nnncr vvvLl

f( )+-P LYI: ON4e

Annulation,

tosylate tsenzyne rs probably generated from o-trimethylsilylphenyl

t1 "U::l-.1^n:*"nthrene is by CsF.Aunion of two benzvnemolecules1d.the f]

.'

-+-< i

t

n

=-/

1,4-Diol monoacetatesundergo Pd-catalyzed elimination of HOAc. This method has beenusedin a synthesisof (-)-shikimic acid.'

,,

\

o'.,1o l

(Ph3P)2PdCt2

n

HCOONH4 IVeCNA

rcat

I

- v Y

,

t ,

o

4.i:.1 lrom bis(pinacolato)diboron s:r..:.rtc'dmacrocyclerepresenting Suzuki couplings n .:.:r.rnrolecular N :.: .trse of develoPment.

I

a

80% N-Arylamines,ttr Arylation of secondaryamines in good regioselectivity is observed when the catalyst is supportedon NaY zeolite. Such catalystsare easily separatedafter the reaction by filtration. Hydrostannylation.tt Regiochemical syn-addition of BujSnH to arylalkynes affords ct-stannylatedstyreneswhen the aromatic ring contains an electron-withdrawing group in the p-position or o-substituentof any electronic nature.

F

: r.':

(Ph3P)2PdCt2 Bu3SnH/ THF

( \{ R=H

R=Br

71Yo

*\

/f

R

,'merization of isoPrene with

r-,-----\.,"t-*r,,

// rH. 'snBr.

38 '. 100 :

rUeda,M., Nishimura,M., Miyaura, N. Sf 856 (2000). 2Huffman,M.A., Yasuda,N. SL 471 (1999). rUemura, K., Shiraishi,D., Noziri, M., Inoue, Y. BCSJ 72, 1063 (1999). aTakahashi,K., Takagi, J., Ishiyama, T., Miyaura, N. CL 126 (2000). sKallan,N.C., Halcomb,R.L. OL2,2687 (2000). 6Maddock, S.M., Finn, M.G. OM 19,2684 (2O0O).

oz

0

7J-SnBuz

, , , , ,-)

7 t n-t ( -

Palladium(tr) chloride-triphenylphosphine-carbon monoxide TKakusawa,N., Yamaguchi, K., Kurita, J., Tsuchiya, T. TL 41, 4143 e}ACii. slwasawa, N., Satoh, H. JACS l2l,':.95t (lggg). eYoshida,N., Ogasawara,K. OL2, 146l (2OOO). 'ODjakovitch, L., Wagner, M., Kohler, K. JOMC 592,225 (lg9g). rrLiron, F., Le Garrec, P.,Alarni, M. 5L246 (1999).

Thiocarbamates,6 The Pd-catalysisavoids using pho Aromatic aldehydes.- | with this catalytic system urxl

Palladium(Il) chloridetriphenylphosphinmarbon monoxide.20, 298-299 Lactams. Dependingon the nature of the imines and their reaction partners, Iactamsarisingfrom the Pd-catalyzed reactionundercarbonmonoxidevary.r.2

3-Alkenamides.E Thesc under the carbonylation reaL-

*

4'-'.o-oet r.! o

H:N F(

(i ' nl

3 -I-

\r.\,-N

Ph..,

(Ph3P)2Pdcr2 +

clvPh ;;,.^,* MecN 1oo"

!1,

4g%

| \

rl-]' AcO

96Yo

I

|:1 =', i t L t

Phenyliodine(Ill)

bis(trifluomacetate)

Dehydration.2 Alkanamides are dehydrated to nitriles by this reagent, but formamides give isonitriles. 'Millan,D.S.,Prager, R.H.AJC 52,841(1999). 2Bose, D.S.,Goud,PR. TL 40,747(1999'). Phenyl(fluoro)iodine triflate. 20, 304-305 Oxidative rearrangement,t (PhIF)OTf induces reiurangement of nonterminal alkynes in an alcohol to give a-branchedesters.

rll + Pn-r-r -il.* pnlcoov" I Ph

rTohma, H., Watanabe, H., Takisag.a-S. rKita, Y., Egi, M., Ohtsubo,M.. Sarh. T 'Kita, Y., Egi, M., Tohma,H. CC l.l_r, l, rVarma, R.S., Kumar, D. "/CS(p/ r I ?J5 i squideau,S., Looney, M.A., pouvscgu-I

Phenyliodine(III)

diacetate.

13. l{

280-281 ; 18, 290-29 | ; 19, 268-: -C Diaryliodonium sulfu natcsadmixture with PhI(OAc)2.2TfOH u

Oxidations, 4-Hydoxy-2-crcl with PhI(OAc)r. 2-Methoxyphenols adducts.3'a

Tfo-

rPirguliyev,N. Sh., Brel, V. K., Zefirov, N. S., Stang,P.J. MC 189 (1999).

Phenyliodine(Ill) bis(trifluoroacetate).13,241,242;14,257; 15,257-258; 16, 274-275: 18, 289-290:19,267-268: 20, 305 Cyclizations,Annulationaccompanies oxidationof N-sulfonyl-4-methoxyanilines with PhI(OCOCFj)2 in the presence of 1-alkenes.r5-Methoxyindoles or indolinesare producedin this one-potreaction.Cyclizationof 3-arylpropylazideswherethe aromatic ring is activated(e.g.,3-methoxylated) to fusedquinoneiminesis observed.2

Meo--4 I ll

* A "rln

Pht(ococF3)2

o€[3'n

9xHr.

MeOOC...,,,1.-.OMe

-l ll\v\oH

+ rt,t€

Acylnitroso compounds gerrre alkenesin situ. O-Acetylationand rc 2-(B-Indolylethyl)oxazolines arc

Ts 65%

2-(m-Methoxyaryl)ethyl benzyl sulfides are similarly cyclized to S-benzyl-2,3dihydrobenzothiophenes.3 Dehydrogenation.a 1, 4-Dihydropyridines are rapidly aromatized on exposure to PhI(OCOCFI)2 although addition of sulfur and microwave irradiation of the mixtures has the sameeffect. Dearomatization.s 2-Substituted l-naphthols are allylated at C-2 when they are exposedto PhI(OCOCF3),and an allylsilane. 1-Trimethylsiloxy-1,3-butadiene also react with the naphthoxyiodonium species.

Pht(ococF3)2

05*."".''o\

cH2ct2

With a (salen)CrCl complex as with PhI(OAc)2is chemoselecrir.e Ring contraction. A facile srr is by oxidationof 2-alkylideneclclo

o tl

(Y^

Phenyliodine(tfl) diacetate

rnles by this reagent, but for-

}, :;.:::rh9€lTl€ntof nonterminalalkynes

=-.lcooMe

l: I

rTohma, H., Watanabe,H., Takisawa, S., Maegawa, T., Kita, y. H Sl, l7g5 (lg9g). 2Kita, Y., Egi, M., ohtsubo, M., Saiki, T., okajima, A., rutuou, r., Tohma, H. cpB 47,24r (rggg). rKita, Y, Egi, M., Tohma, H. CC 143 .:Igg9\. rVarma. R.S.. Kumar. D. JCS(pt ) l7S5 (lgggt. sQuideau, S., Looney,M.A., pouysegu. L. OL l,I651 (1999).

Phenyliodine(Ill)diacetate.13,242_243;14,25g_259;15,25g;16,275_276;17, 280-281;18,290-291;19,268_270;20, 305_307 Diaryliodonium surfonates. These salts are prepared from ArB(oH), upon admixrurewith phI(OAc)2.zTfOHin dichloromethane. I oxidations' 4-Hydoxy-2-cyclobutenones are oxidized to -y-acetoxybutenorides2 with PhI(oAc)r. 2-Methoxyphenols give o-quinonesthat can be ffappedu, Di"lr-Ald". adducts.3'a

.q, 1999).

l/

t . '

I J. 157; 15, 257-258; 16,

Meooc)i'lYo'" * ""o$ ffi \V\oH

''i

.\'-sulfonyl-4-methoxyanilines ' \lc-thoxyindolesor indolines are

OMe

#ffi"""

rsoH_H2c

\_/

a(

' , .:rlnesis observed.2

.

\{eo:y';-1

-

|

ll

\An'\

) . t

aziridineesters.la

t-BuoK/rHF Ph"\,\-cHo

-'0"

|

I

j.,

t ' 4

o

71Yo

,oMe \-o

a ' r

iti = f'-

Amides. Conversionof ".te.. r.l heating with solid t-BuOK.i: Orrd.rr aldehydeswith t-BuOK in DMSO alro Hydrolysis. Amino esters ro- a (r-BuOK-THF) at 0' or belor,r'.Thrr

2-Alkylideneglutaronitriles are readily formed by consecutive Michael and Wittig reactions.6 The process involves addition of the cyanomethylphosphonate anion to acrylonitrile and quenching the homologated anion with aldehydes.

IBUOK / THF . HN,IPA ;

ot l

ffiP;.cru

.

\

\

J

on"'-*t

Y / \

t-BuOK

--f

2a

Ph,,\.CN

PhCHO;HCl-H2O

I )

CN

CN

Claisen rearrangement Allrl d propargyl ethers with l-BuOK are rc.( o-substitutedacroleinsis established

72o/o Cyclizntians. Synthesis of substituted indoles from o-haloanilines by condensation with ketones?or nitriless is promoted by t-BuOK in DMSO. Furansare formed from a-propargyl ketones.qAlkynyl benzyl sulfidescyclize to give 2-aryl-2,3-dihydrothiophenes.r0 Deprotonation at the benzylic position initiates the cyclization.

l--\

( \:

./

,r-s

\

N

\}-r \\ / \ \

t ? \

(YY '

I-BUOK/ THF

,)'\?-.'

I-BUOK/MeCN

Al.dol reactions. A reagentconur Addition to styrenes. A caralrrr additionof ketonesand iminesto sgl6

o. 7SYo

at room temperaturein either DITISOtr

Potassium,-butoxide

-\n alkyne synthesis bY chain rh, -rhonium salts as Wittig reagent r:l:lrning whether the products are

Aromatic substitutions. 2-Nitroaryl-1,3-dithianes are assembled by the vicarious II nucleoohilicsubstitution on nitroarenes.

/ _r:il^N. -50'

R=l

+25o R=H

95Yo

97Yo |'lYo

f-i:fi()lates and their O-acylatedand

Amides. Conversionof estersto amides in a solvent-freeprocessuses mrcrowave heating with solid t-BuOK.12Oxidative decyanationof ct-aminonitrilesderived from aldehydeswith r-BuOK in DMSO also afford amides.rl Hydrolysis. Amino esters (ct- and B-) are cleaved under nonaqueous conditions (I-BuOK-THB at 0o or below. This method proves valuable for kinetic resolution of aziridineesters.ra

Ph\cHo ;_

o ,oMe \_o

75% t^. ,,)n\ecutive Michael and Wittig anion to i -r.1nr)methylphosphonate

o

L-{ K

Phs

\

I B U O K/ T H F

20"

r ::: .!lJehydes.

c - ,

(""fv. /\

,^...!_*X 42%

PhryCN I \ I CN

o

(o""-.\.o^ ,n.!tX 58To

Clnisen rearrangemenf. Allyl allenyl ethers resulting from isomerizationof allyl A route to propargyl etherswith l-BuOK are ready to undergoClaisen rearrangement.l5 o-substitutedacroleinsis established.

72Yo ; :: nr o-haloanilinesby condensation

[ ) \ 1\ o \:i.::rr I benzyl sulfidescyclize to give r:.. hcnzylic position initiates the

| ?-\

(YY a'.O"-

IBUOK / THF

\

| ?^cs I o*,, /'< \-st_Ph /

Y

.,Jo-\-/ \

MeoocAN2 81%

\

Rhodium carborylates I 'Matsuda,I.,Takeuchi,K.,ltoh, K.TL40,2553 (lggg). 2Matsuda,I., Niikawa, N., Kuwabara, R., Inoue, H., Nagashima, H., Itoh, K' JOMC 574' 133 (1999). rFukuta, Y., Matsuda, I., Itoh, K. TL 40,4703 (1999).

l-,

r.

.rrr)n of rhodium trichloride with r,,nium salts) is effective for ,,rnrtemperatureunder biphasic

Rhodium carboxylates.13,266;15, 2'18-286;16,289-292;17,298-302; 18, 306-307; 19, 281-285; 20, 318-320 Carbenoidinsertions. Advantagehas beentaken of the insertionreactionin the o-silyl a-amino acid derivatives,2functionalized formation of dehydropeptides,l andspiranesystems.5 1,4-dioxenes,a tetrahydrofuranones,3

Ph,,zyo ' '

ro) Ho2

MeoocANz

Rh2(oAc)4

t'*;i

Ph'4\'O

rraeoocAo

ri 16:19,280-281;20,317-318

42Yo

u...,. rrrlc to suppresshydrogenation -. : . I rroup of a divinylpynole can be : r - - . ' r - l r n k e vdi n y l r e s i d u e . 2 lr :

*

Nz\

"{_I}" /zN,

,t c'thynylarenesin the presence

oil,zRh2(oAc)4

lA{"

#

27Yo

4Y,|

- R - -

\-\

/

cooR'

)

o , ,.1 599.198(2000). l, "' 5e2.69( 1999). a - : . : 1 1 - , 1 0 , 7 8(1119 9 9 ) .

The insertion at C-2 and C-5 of N-Boc-pynolidine in the presenceof Rhz[(S)-DOSP]r gives rise to C2-symmetriccompounds.6On the other hand, by using Rh2[(R)-DOSP]aas the catalyst, the reaction leads to mixtures of diastereomersand regioisomers.

N2

|\v

ru-Aoc +

FCOOMe Ar

Rh?(s-DosP)4

---..----------.----.--N - B o c COOMe

lc..i

...:rhthis reagentcombinationcan or cyclizationproducts,r ,..i.'hvdes,r

1l' .

.:ir-':tfUCtUf€S.

fK..'

A key building block for synthesis of eburnamonine was assembledby the reaction taking advantageof the preferred insertion into a tertiary C-H bond by Rh-carbenoids.T

cHo

us1_en 81%

o MeOOC

(-)-eburnamonine

I

I

, ,

368

Rhodiumcarboxylates

o

An exceptionally reactive and selective chiral dirhodiumlll.l carboxJmides, Rh2[(4S)MEAZI4, has the potential to significantly broaden the applicability of asymmetric synthesisusing diazocarbonyl compounds.8 Rearrangements. A variety of reactions catalyzed by Rh(II) carboxylates, including Wolff reanangement of 3-diazo-2,4-dioxo-1,2,3,4-tetrahydroquinolinesleading to oxindoles due to in situ decarboxylation,einsertion followed by [2,3]sigmatropic

/h tl o

reilrangementr0and Claisen rearangement,lr serve to affirm their synthetic potential.

o I

Y\-.sen * ?'""' \N,

SiMe3 Rh2(OAc)a

sen

)

/--,.

ll ct'Y

o

\

I

86%

) / 2

Four-membered rings.t2 Rearrangement of a-diazo thiol esters to substituted ketenes and cycloaddition of the latter to alkenes lead to cyclobutanones. A similar addition to imines gives BJactams.

tI rl .-/ , '

7--

, - '

t=

Wolff rearrangement. Srlrl I on exposureto rhodrurwI diazoketones Nr

||-

R' Y A - s i E b

t i.' l.llr i

o o

ll *, pns'tr'rzN'.

Rhz(oAc)4

\-1

(i

.""il-

b^

Phs?-)

1

73-78o/.

Diheterobicycloalkanes.tt Hydroformylation of l-alkenes that contain in-chain heteroatomsis terminated by cyclization.

a^---1 a*r \.,^-/ \-NH,

H 2 tc o Rh2(OAc)a phosphine

-." Rh2(OCCJ4 PhH

?]

o

\---l

.

*

a-r*€ \-t'tH

80To

rBuck, R.T., Clarke, PA., Coe. D.\l . Iln N . D . . S w a n n .E . C E J 6 , 2 1 6 0 ( 2 0 0 O ' :Bolm, C., Kasyan,A., Drauz, K.. Gunrlrr 'Lacrampe, Leost, F., Doutheau.A Il, F., rHilgenkamp,R., Brogan,J.B.. Zerctrr- C 5Aburel.P.S..Undheim. K. JCS(P1r lt9l r ('Davies, H.M.L., Hansen,T., Hopper.D rt ' W e e ,A . G . H . ,Y u , Q. fL 41,587(lm, rDoyle, M.P., Davies,S.B., Hu. W. Ol !. I 'Lee, Y.R., Suk, J.Y.,Kim, B.S. fL {1. 8:l r{' Carter. D.S.. Van Vranken.D.L. fL {0. l6 rrWood, J.L., Moniz, G.A., Pflum. D .{ . Se

( 1999). rrLawlor, M.D., Lee, T.W., Danheiser.R L 'tBergmann,D.J., Campi, E.M.. Jac\soo"u rrPimrng, M.C., Kaliappan,K.P OL 2. 353 I 5 M a r s d e nS, . P , P a n g ,W . - K . C C I 1 9 9 r l s Rhodium

Carbonyl ylides generated from 6- and 8-carbonyl-c[3*2]Cycloadditions.ta diazoketones undergo cycloaddition with quinones. Chemoselectivity (C:C vs. C:O) of the reaction is dependenton the solvent and catalyst.

perfl uorocarboxylates.

Alkoxy c arb o ny lm ethy I en o I c{., from carbonyl

compounds

is b1 a R

ester. The enol etherification is applrcd

Rhodium perfluorocarboxylates

o tl

rc:.-::r,il ) carboxamides,Rhz[(a,S)::: rpplicability of asymmetric

.r-Yo

a-..,tJ hy Rh(II) carboxYlates, l. : j tctrahydroquinolinesleading t : :, 'lltrwed by [2,3]sigmatroPic

Rh2(ocoA04

[].::: their syntheticPotential.

Rhz(OCOAT)r

SiMeg

I

)fsen - I \

\

N2

860/o

.

64Yo

c . , , . , t h i o l e s t e r st o s u b s t i t u t e d A similar ei.: r,' cvclobutanones.

Wolff rearrangement. Silyl ketenes are readily on exposureto rhodium(Ilt octanoate.rs diazoketones

R

73-78o/o

L c n e s t h a t contain in-chain

,"'rrrry

/

-J

80o/o

R'NH2 -+ cH2cr/

from

ct-silyl-ct-

_ t -2\.l R

' ' Y ' r u 'r\ iiet. H

IBuck, R.T., Clarke, P.A., Coe, D.M., Drysdale,M.J., Ferris, L', Haigh, D.' Moody' C'J', Pearson, N . D . . S w a n n .E . C E I 6 . 2 1 6 0 ( 2 0 0 0 ) . rBolm, C., Kasyan, A., Drauz, K., Gunther, K., Raabe,G. ACIEE 39' 2288 (2000). rlacrampe, F., Leost, F., Doutheau, A. TL 41,4773 (2000)aHilgenkamp,R., Brogan,J.B.,Zercher,C.K. H51, 1073 (1999). 5Aburel,P.S.,Undheim, K. JCS(PI) 1891 (2000). 6Davies,H.M.L., Hansen,T., Hopper,D.W., Panaro,S.A. "/ACSl2l' 6509 (1999). 7Wee,A.G.H., Yu, Q. ZL 41, 587 (2000). sDoyle,M.P, Davies,S.B., Hu',W. OL2, 1145(2000) elee, Y.R., Suk, J.Y.,Kim, B.S. TL40,8219 (1999). l{)Carter.D.S.. Van Vranken, D.L. TL 40,161'7 (1999). lrWood,J.L., Moniz, G.A., Pflum, D.A., Stoltz, B.M., Holubec'A.A.' Dietrich, H.-J. ,/ACSl2l' l'748 ( l 999). lrLawlor. M.D., Lee, T.W., Danheiser,R.L. JOC 65,4375 (2000)' lrBergmann,D.J., Campi, E.M., Jackson,W.R., Patti,A.F. CC 12'19(1999). raPimrng,M.C., Kaliappan,K.P. OL 2, 353 (2000). r5Marsden,S.P.,Pang,W.-K. CC 1199(1999). Rhodium

a:-.: Ir()m 6- and E-carbonYl-c}.::::,'.clcctivity(C:C vs. C:O)

RVsiEt3 Rh2(ococ7Hls)4 llz ,j\ -SiEt3 ll PhH 20' C Y O O

formed

perfl uorocarboxylates.

Alkoxycarbonylmethyl from carbonyl

compounds

enol ethers.t

A convenient preparation of these enol ethers

is by a Rhr(OCOCF.T) 4-catalyzed reaction of a diazoacetic

ester. The enol etherification is applicable to ct-pyridone.

I

I ) ,

Ruthenim-+arbene complexes

. ,,,,,,,,,,,,,,,,Hr,_o {_cooEt

Rh2(ococFj)4

\

/-COOEt

/-\

,-\

,. |

clcHzcH2ct o

//-

v

I

PCys

\___!

ct"..] 69%

/Ph oc,r ct

c r . lI' J

PCYg rBusch-Petersen, J.,Corey,EJ. OL2,1641(2000).

I

(1)

Rhodium(Ilf

chloride. Aryl ketones.l Benzyl alcohols and alkenes are united by a catalytic reaction using polymeric phosphine ligated RhCl3hydrate.

/

{

n l

\ \

z)-N..rN{-)-

t

I "^ "r '. : R u =r

CI. I

\J

PCve RhCl3 x H2O

I

,

r \

(4)

Ph3P r.f PhMe

o-N

NH,

rJun,C.-H., Hong, H.-S., Huh, C.-W. TL40,8897 Oggg).

i1"i'-1"q -X--

o

R = Me, CF: Ruthenium-<arbene complexes. 18, 308; 19, 285-289; 20, 320_323 The prevalentcatalystsfor metatheticreactionsof alkenesor alkynes are 1,2,3, 4, and 5. Those containing imidazol-2-ylidene ligands are readily prepared from 1 by ligand exchange.' complex 6 is a precatalyst for various ring-closing metathesis (RCM) reactions.2 Its counterion affects reactivity and selectivity. The immobilization of the Ru complexes to polymer yields a series of RCM catalysts that are recyclable and possess comparable or better reactivity than their homogeneouscounterparts,particularly in dealing with highly hindered substrates.3-5 The four-coordinate complexes 7, which possesstrigonal pyramidal geometnes, zue moderately effective RCM catalysts, but reactions involving them are greatly accelerated by the addition of HCl.6 Also prepared from I and allyl 2-bromo-2-methylpropanaoteis a multifunctional catalyst 8 that is capable of mediating three mechanistically distinct reactionsT:ring-opening metathetic polymerization, atom-transferradical polymerization, and hydrogenation. The use of tris(hydroxymethyl)phosphine is recommended for removal of the ruthenium residue from the products.8Addition of a modest amount of pb(oAc)a (1.5 equiv relative to the Grubbs catalyst) at the end of the reaction rids all the colored imnurities.e

(7)

Metathetic rtng closure. ( tbr RCM and the scope of ru the elaboration of cyclic srruc those containing phosphine o I -(Dialkoxyboryl)vinylcycloal\a Formation of a /rcns-cycloct the metathesis(using either I cr r undergocyclization.I8

/-cooEt

/

./-\ ---J

PCys

cr,,.| .,tlui

,Ph

BF; h

?"t' ""1:lo:r:,,

I

PCys (1)

pCvr

5

4

I

\

371

comPlexes

Ruthenium-carbene

\

// \\ F-

z)-N..,,N-L-)-

t

r

I UI" RU:r 'Ph cl' | ' PCy:'

\

(3s) C+-Cssaturated (3u) C+-Csunsaturated

(2)

-. r:\ \_ir\r,i!_>

.J by a catalytic reaction using

Bn,, 1,,_ Ph

,'._,1"

rLi-\", (5)

(4)

PCYg R ,O,,. I ,Ph RuJ X R \ ^ I t ( n

^">(-R K ' R

ct,,...,1 * ,*'--^ "--a**,

RsP-

X

I

K

,

(6)

o / PCYg )-F Br c1,,. I ro ^ , r l Iu i

i I

PCYs

D

R = Me, CFs r. l(1..120-323 fr .:-rcncSor alkynesarc l, 2, 3, 4, rf :r.iJrlv preparedfrom I by ligand rr.--..,'singmetathesis(RCM) reac-r:, Ihc immobilization of the Ru r.:. lhat are recyclableand possess L. - 'unrerparts,particularlyin deal, ': -.'nrl pyramidalgeometries.are r ..::rg them are greatly accelerated 11 -'rromo-2-methylpropanaoteis a distinctreacg ':' . r' mechanistically -:: j::.1dr radical polymerization,and nr::.cndedfor removal of the rutheIr.: .unountof Pb(OAc)a(1.5 equiv r, :. ::J' rll the coloredimpurities.q

(7)

(e)

(8) PCvr - -rSePh Ct,,. |

^,rlui I

PCYs (10) Metathetic rtng closure. Catalyst 1 pan be regarded as the standard workhorse for RCM and the scope of its applications continues to expand. Thus, its use in and 3-pyrrolines,rr'12 the elaboration of cyclic structures including azaspirocycles,l0 sulfonamides.r6 dioxasilanes,rs those containing phosphine oxides,lr phosphinates,ra l-(Dialkoxyboryl)vinylcycloalkenesare obtainedfromx-alken-1-ynyl boronates.rT Formation of a tans-cyclooctene system reveals a profound stereochemicaleffect of the metathesis(using either I or the Schrock catalyst). The other diastereoisomerdoes not undergocyclization.r8

It

Ruthenium-carbene

complexes

Structural modifications such el high efficiency. (1)

,,,rr--a '

n,,T--

o-t/o tl

o-t/o tl

I

e$!€.

oTBS

uh:_.:

on elaboration of 1,5-hexadiene-3,4-diolthrough a l,3-dioxolane derivative, the RCM delivers a precursor of either e-ro-brevicomin or endo-brevicomin.reA route to ( + )malyngolidealso exploits the RCM process.20A successfulcyclization-fragmenrauonapproach to medium-sized rings is based on the RCM reaction of 2-hydroxycycloalkanones that are substitutedwith proper alkenyl groupsat both ct- and ct,_positions.2r

)ro1." o i! A"\z ,

exo-brevicomin

)r-, "o

2

Higher activity of catalysts eo RCM has been observed.r{Such cr tuted cycloalkenes,25'26 and vanotrs highly active catalyst 9 is recover{

ETOOC r

t

: llt,t '- lti'

OTBS

/\

'.. p;

(1)

AJ,,,,r'

/J,

+H2

'

endo-brevicomin

ETOOC\

Cross-metathesis. Funcumrl using catalyst I has been well esrl gives to-silylstyrenes,2e bet*eto butenonitriles.30Alternativell. ho 1,4-diaryl-2-buteneis first camed < is the homo-metathesisof monosub

\

o +

q^*ottt

+

r

{z |

\

l

Rz\'c\ I

q^#""'n -ro

l-o

92%

(+)-malyngolide

Both catalysts I and 2 are effcr conjugateddienes from alkenesand is obtained from (R)-3-acetoxr-Furthermore,the reaction of 1.6{rv

COOMe (1)

osiMe3

\ --\ f

Pb(OAc)a

o n = 0 ,1

11 \ l t >-+4" o

Ts R--N-..,

rlrr

Ruthenium-carbene

complexes

are pleasing becauseof their Structural modifications such as those shown below22'23 high efficiency.

i")

o

(1)

o

ethylene cH2cl2

OTBS

a . ' . t..:. 'r_.:. t

,

** a$,", t

tl

l.l-dioxolane derivative, the ,-brevicomin.re A routeto (+)I er clization-fragmentationap,,n of 2-hydroxycycloalkanones ':r,1o'-positions.2l

t

u

bn

OTBS

Higher activity of catalysts embodying imidazolin-2-ylidene ligands (e.g., 3u) for RCM has been observed.2aSuch complexes as 3u and 5 allow formation of tetrasubstiThe and various functionalized analogues(e.g., 1-cyanoalkenes2T). tuted cycloalkenes,25'26 highly active catalyst 9 is recoverableand recyclable.28

ETOOC\f-/ x + Etooc'

exo-brevicomin

(3u) ETOOCV^I / \ r l \"/ Etooc-

,

100Yo Cross-metathesis. Functionalization of terminal alkenes by the metathetic method using catalyst L has been well established.The reaction between styrene and vinylsilanes gives co-silylstyrenes,2ebetween allylarenes and acrylonitrile leads to 4-aryl-2butenonitriles.3oAlternatively, homo-metathesis of two allylarene molecules to give 1,4-diaryl-2-buteneis first carried out and the cross-metathesisfollows.rr Also of interest

- -l-.,-1 6 - | endo-brevicomin

is the homo-metathesisof monosubstitutedallenes to symmetrical allenes.r2

s

tt'

RAc-

-

RAn

"cgHrg I

CgHrs

[

(+)-malyngolide

Both catalysts I and 2 are effective in promoting cross-metathesisleading to vanous conjugateddienes from alkenesand alkynes.13s4Chiral2-(ct-acetoxybenzyl)-1,3-butadiene is obtained from (R)-3-acetoxy-3-phenylpropynevia cross-metathesiswith ethylene.rs Furthermore,the reaction of 1,6-diyneswith alkenesis even more intriguing:r6

COOMe

.

-: .*

/ -)--.- \ / \

\

\-+/f Il o

ll

-n

Ts R -,.

I

N.r

-\

l*

ilt ill

(1)

'R'------*

I a

Ia

Ruthenium--carbenecomplexes

The scope is further expandedby using catalysts 3s37.38 and 4.3eFor example, it allows the preparation of trisubstituted alkenes by an intermolecular reaction for the first time,a0 and 1,5-cyclooctadienes(e.g., a precursor of aristeriscanolidear).The intramolecular version is a useful preparation of some other interesting molecules.a2

74Yo

aristeriscanolide

Technically significant is the finding that 4 can be generated in situ from I and 1,3-dimesityl-4,5-dihydroimidazolium tetrafluoroborate (treatment of the salt with I-BUOK in THF at room temperaturefor < I min). The RCM is performed in the presence of etherealHCl.a3 Complex 10 is a very active catalyst for ring-opening cross-metathesisof norbornene derivatives.aa [2 + 2 + 2]Cycloaddition. Formation of benzene derivatives from three alkyne units is catalyzed by several transition metal reagents. 1,2,4-Trisubstitutedbenzenesare the major products from reactions using the Grubbs catalyst containing Ph.P ligands.as Differences in regioselectivty for reactions promoted by the Grubbs and Wilkinson catalystshave been noted.ab

*or. (1)

RO-\ cH2ct2

Ro. ,:Co"

lf*.Y maJor

*T.li -,,*35*.r.*d* (1) 5-6 (Ph3P)3RhCl 1 Radical addition.aj (PhjP)2Ru(:CHPh)C12.

'l 1. 5 - 1 0

Carbon tetrachloride adds to alkenes in the presence of

Scholl,M., Ding, S., Lee, C.W.. Grubtr :Fiirstner, A., Liebl, M., t-ehmann. C Dixneuf, P.H. CEJ 1847 (20001. 'Jafarpour, L., Nolan, S.P OZ 2. JO-: ': 'Yao, 39, 3896 (2000t ACIEE Q. 'schiirer, S.C.,Gessler,S., Buschmann ''Sanford, M.S., Henling, L.M.. Da1. \l' -Bielawski, C.W., Louie, J., Grubbs.R I 'Maynard, H.D., Grubbs,R.H. Il {l. J 'Paquette,L.A., Schloss,J.D.. Efrenx-r

l 259 (2000). Wright, D.L., Schulte,J.P, Page.\l .\ Evans,P.,Gngg, R., Monteith. It rl I :Bujard, M., Briot, A., Gouverneur.\ . ! 'Trevitt. M.. Gouverneur,V.. Mios\orr 'Bujard, M., Gouverneur,V., Mioskorr 'Hoye, T.R., Promo, M.A. IL 40. lr-'9 ^Hanson, P.R.,Probst,D'A.. Robrn( \

l

>-N

/

Bn 93Yo

'Keck, G.E., Wager, C.A., Sell, T., Wager, T.T. JOC 64,2172 (1999). 2Keck,G.E., Wager,C.A. OL2,230'1 (2000). 3Keck, G.E., Wager, C.A., McHardy, S.F. 255, 11755 (1999). aMcAuley, B.J., Nieuwenhuyzen, M., Sheldrake,G.N. Ot 2, 1457 (2O0O). 5Knowles,H.S., Parsons,A.F., Pettifer,R.M., Rickling, S. f 56, 979 (2000). 6Guo, H., Zhang,Y. JCR(S) 342 (1999). 7Guo,H., Zhang,Y. SC30, 1879 (2000). oHanamoto,T., Shimomoto, N., Kikukawa, T., Inanaga, J.TAl0,295l (1999). eHonda,T.. Ishikawa.F. CC 1065 (1999). r0Honda,T., Kimura, M. OL2,3925 (200U. rrKato, Y., Mase, T. fL 40, 8823 (1999). 12zhv,I.-L., Shia,K.S., Liu. H.-J. TL40.'7055 ,]l99q). I3Kim, S.M., Byun, I.S., KLm,Y.H.ACIEE 39,725 (2000). raPedersen,H.L., Christensen, T.B., Enemaerke, R.J., Daasbjerg, K., Skrypdstrup,T. EJOC 565 ( 1999). rsYamashita,M., Okiyama, K., Ohhara, T., Kawasaki, I., Michihiro, Y, Sakamaki, K., Ito, S., Ohta, ,:Iggg\. s. cPB 47. 1439 'nMachrouhi,F., Namy, J.-L. TL 40, 1315 (1999). r7Lu,L., Chang,H.-Y., Fang,J.-M. JOC 64,843 (1999). r8Mukaiyama,T., tuai, H., Shiina,I. Cf 580 (2000). reRicci, M., Madariaga, L., Skrydstrup, T. ACIEE 39,243 (2000). 20Fukuzawa,S., Matsuzawa, H., Yoshimitsu, S. ./OC 65, l7O2 (20OO). 2rBaek,H.S., Yoo, B.W., Keum, S.R.,Yoon, C.M., Kim, S.H., Kim, J.H. SC30,31 (2000). 22zhou,L., Zhang, Y - SC 30, 597 (2000). 2rsakai,H., Hagiwara,H., Ito, Y, Hoshi, T., Suzuki,T., Ando, M. TL40,2965 (1999). 2aSono,M., Hashimoto,A., Nakashima,K., Tori, M. TL 41,5115 (2000). 25Caracoti, A., Flowers II, R.A. TL 41, 3039 (2000). r6Hsu,J.-L., Chen, C.-T., Fang,J.-M. OL2,1989 (2000). zTKunishima,M., Yoshimura,K., Nakata,D., Hioki, K., Tani, S. CPB 47,1196 (1999). 28Youn,S.W.,Park, H.S., Kim, Y.H. CC 2005 (2000). reHuang,Z.-2, Jin, H.-W, Duan, D.-H., Huang, X. JCR(S) 564 (1999). r0Ha,D.-C., Yun, C.-S.,Lee,Y. JOC 65,621 (2000). rrKan, T., Nara, S., Ozawa,T.,Shirahama,H., Matsuda,F. ACIEE 39,355 (2000). r2Kang,H.Y, Song,S.E. TL41,937 (2000). rrMolander, G.A., Machrouhi F. JOC 64, 4119 (1999). , taZhor,L.,Zhang,Y., Shi, D. S 9l (2000). r5Matsuda,F., Kawatsura,M., Hosaka,K., Shirahama,H. CEJ 5,3252 (1999). r6Aurrecoechea, J.M., Fananas, R., Arrate, M., Gorgojo, J.M., Aurrekoetxea, N. JOC 64, 1893 (1999\. r7O'Neill, D.J., Helquist,P. OL l, 1659(1999). rsDavid,H., Alfonso, C., Bonin, M., Doisneau,G., Guillerez,M.-G., Guibe,F. TL 40,8557 (1999). reJohnston,D., McCusker,C.F.,Muir, K., Procter,D.J. JCS(Pl) 681 (2000). r(rAurrecoechea, J.M., Fernandez,A., Gorgojo,J.M., Saornil,C. f 55,7345 (1999). llKatritzky, A.R.,Luo,Z-, Fang,Y, Feng,D., Ghiviriga, l. JCS(P2) 1375(2000). l2Tanaka,T., Wakayama, R., Maeda, S., Mikamiyama, H., Maezaki, N., Ohno, H. CC 1287 (2000). rrNandanan,8.,Dinesh,C.U., Reissig,H.-U.256, 4267(2000). 'oXu, F., Sun, J.-H., Yan, H.-B., Shen, SC 30, 1017 (2000). Q. asConcellon,J.M., Bernad, PL., Perez-Andres,J.A. ACIEE 38,2384 (1999). 'oKatritzky,A.R., Feng,D., Fang,Y. SZ 590 (1999). rTNishitani,T., Shiraishi,H., Sakaguchi,S., Ishii, Y. TL 41,3389 (2000).

F

Samarium(Ill) triflate

SamariumflIl) iodide. pAmino esters,l Promotedby SmIj the condensation of silyl ketene acetals with aldiminesis highly anti-selective.

on"* OSiMe3

ErO

Sml3

*

(*,,tn THF : OTBS An- p-anisyl

H N

NHAn I EtOOCv&.Ph

e{

: OTBS

)-sa6 ,

thioglycosides that are not acu valuable feature. rChang, G.X.,Lowary,T.L.OL 2.

Samarium(Il) trifl ate-nickdt Alkylations.l Samariumrtl taining catalytic amounts of H.

with NiI, for condensationof h

Go.=

rHayakawa,R., Shimizu, M. Cl,59l (1999).

triflate. Samarium(Il) iodidesamarium(IlD Reduction.t With this combination of reagents,methanol and base (KOH), reduction of carboxylic acids to primary alcohols is observed.Aldehydes are hardly affected.

Various reactions.t The b reaction, Mukaiyarna-aldol ra reaction, as well as the reductrr

rKamochi, Y.,Kudo,T.TL4l,341 (2000).

rCollin,J.,Giuseppone, N., l\lrtrr

isopropoxide. and nitroalkenes undergo condensation to afford 1,3,4+risubsti Imines firroleil tuted pyrroles. For the promotion of this reaction, samarium(Ill) isopropoxide is better than severalother Sm compounds and isopropoxides of lanthanum and ytterbium.

Scandium(Ill) triflate. lt. -1I i Allylation. When tetra.lllll pounds, the presenceof water I

Samarium(Ill)

(i-PrO)3Sm

.,]--r^*-

*

r',,/\r'*o'

IHF A

Aldol reactions. To condr water, the presenceof a surfat employed as surfactants.' ..\ h enol ethers,thereby increasing r

Vinylogous aldol reactrcxr alkenyloxiranes and aldehl dcs teric charactersin that thev beh

{ */:*\ 70To

o 'Shiraishi, S.,Ishii,Y f55, 13957(1999). T.,Nishihara, T., Sakaguchi, H., Nishitani,

Samarium(Ill) triflate. Glycosylation.r Samarium(Ill) triflate catalyzes the reaction of glycosyl 2-pyndyl sulfones with alcohols. This method is applicable to the preparation of di- and trisaccharides containing both furanose and pyranose residues. The difference in reactivity from

*\^*

I

Mannich reactions. F-.fu Sc(OTf)r-catalyzed condensarx taining a surfactant.5Under rlx imines in MeCN to provide p-e

ScandiumflIl)

rr..:!:r..rtionof silyl ketene acetalswith

triflate

thioglycosides that are not activated by the hard Lewis acid Sm(OTf)r is a synthetically valuable feature. rChang,G.X.,Lowary,T.L.OL2,1505(2000).

H N

\HAN

l o ^ : OTBS

- -'t-,/ -

o{

"'

Fonc :

Samarium(Il) triflate-nickel(Il) iodide. Alkylations.t Samarium(Il) triflate is prepared by reduction with Sm in DME containing catalytic amounts of Hg.'The solvated product is freed of solvent and combined with NiI2 for condensationofketones and acrylic estersto afford ylactones.

( F o L-J

nr. :Icthanol and base(KOH), reduction a.- \ldchydes are hardlY affected.

COOMe

Sm(OT02- Nil2 EtOH

\

f--t,ro-(o \-/\

Various reactions,t The binary salt is a very useful reagent for promoting Barbier reaction, Mukaiyama-aldol reaction, Michael reaction, Mannich reaction, Diels-Alder reaction,as well as the reductivecoupling ofcarbonyl compoundsand ofimines. rCollin,J.,Giuseppone, N., Machrouhi, F.,Namy,J.-L.,Nief,F. TL 40,3161(1999).

o . rJcnsation to afford 1,3,4-trisubstio:. ..rnrarium(lll) isopropoxideis better rc:. ,t lrnthanumand Ytterbium.

{

Scandium(Ill) triflate. 18, 3 I 7-3 I 8 ; 19, 3OO-302;20, 335-337 Allylation. When tetrallylgermane is used as the allylating agent for carbonyl compounds,the presenceof water in the reactionmedium is indispensable.r Aldol reactions. To conduct the Sc(OTf);catalyzed Mukaiyama aldol reaction in water, the presenceof a surfactantis very advantageous.2Calixarenesulfonatesalts can be employed as surfactants.i A hydrophobic microenvironment is created to protect silyl enol ethers,thereby increasing the yields of the products. Vinylogous aldol reactions leading to D-hydroxy-cr,P-unsaturatedaldehydesa from

I

alkenyloxiranes and aldehydesare promoted by Sc(OTf):. Such oxiranes possessamphoteric charactersin that they behaveas acceptorstoward allylborate reagents.

N--r

Ph/=/

\ 7lYo

tl S ..::rr.\'. f 55,13957(1999).

rlr.'r. rhe reaction of glycosyl 2-pyridyl le :,' the preparation of di- and trisacchas:.:-.. The difference in reactivity from

R^H

.of

SC(OTO3

-;;*

OH

' nt-* |

/cHo I

Mannich reactions. B-Amino ketones and esters are readily obtained from a Sc(OTf)j-catalyzed condensation of silyl enolates, aldehydes, and amines in water containing a surfactant.5Under the influence of Sc(OTf):, O-trimethylsilylnitronates add to imines in MeCN to orovide B-aminonitroalkanes.6

ScandiumflIl) triflate

Mechanistically related to the Mannich reaction is the formation of hydroxyarylglycine derivativesin a three-component reaction.T OH

OH

.

\

*o

!r)

NHAr

Sc(OTf)3- N.4gSOa

+ ArNH2 +

'.,A.oo*.

cH2cl2 25

Ttshchenka reaction. Reduction of B-hydroxy ketones with isobutyraldehyde while catalyzed by Sc(OTf)3 is stereoselective,anti-7,3-diol monoisobutyrates are the major products.s Cyclacondensation. A Prins-type reaction between aldehydesand 3-butenol leads to 4-tetrahydropyranolsand ethers.eSc(OTf).r assistsepoxide opening by an intramolecular attack of an enolate,resulting in the formation of three-, four-, and five-memberedrings.r0

) , t

? |

o t

't

Sc(OT03

7-

94To

tipurpose catalyst. Besides proflx{x Diels-Alder reactionand Meergern-

PhMe 25'

)t

)' ('

en\A,^oH

Scandium(Ill) tris(perfl uorullu DebenzylationI Benzyl e0rrs. cleavedby catalysisof Sc(CTf, r. Friedel-Crafts acylatian.: St-an

(Me3Si)2NLi

tr\

Secondary alkyl mesylates are adequate alkyl donors in this reaction.rr Both Sc(OTf)3 and TfOH can be used as the catalyst. It has also been reported that Sc(OTf)3 immobilized in ionic liquid forms a recyclable system for arene alkylation with alkenes.12 Friedel-Crafts

alkylation.

1,l-Diarylalkenes are formed in the reaction of areneswith l-phenylalkynes. Triflates of Sc. In, andZr aresuitablecatalysts.rr Hydrolysis.ta Esters bearing a coordinative group at a proximal position are hydrolyzed selectively under mild conditions, in the presenceof Sc(OTf)3.

o Z\A I

\.ry

ll

rlshihara, K., Hiraiwa,Y.,Yamamoro. ll rNishikido, J.,Yamamoto, F.,Nakarrmrt

Selenium. 18, 318; 20, 337 Alke ny lselenium compounds. alkenylzirconocene derivatives.Ttr 1 acetylated.2

Selcnides and diselenides.' 81 prepareeither RSeR' or RSeSeR'

o

),,,oRc -+

sc(orr)3 Z>A

MeoH- H2o

|

MeOH - H2O

ll

),,,oH

A--{\ I ll \.ry

BuLi + 2Se -

FoH

Silyl ethers.ts Silylation of alcohols at room temperatureusing methallyl(t-butyl)dimethylsilane as TBS group donor is catalyzedby Sc(OTf )3.

|rt

rAkiyama,T., Iwai, J., Sugano. \t. f 55. 2Manabe,K., Kobayashi,S. SL 5{7 r 199 rTian, H.-Y., Chen, Y-J., Wang. D,. Zrq alautens,M., Ouellet,S.G., Raeppel.S sKobayashi,S., Busujima,T.. Nagar arru 6Anderson,J.C., Peace,S., Pih. S. St S! THuang,T., Li, C.-J. TL 41,6715 r)U,t',t EGillespie,K.M., Munslow, I.J.. Sccn. P "Zhang,W.-C.,Li, C.-J. 256, 2.lO-1' l(n roCrotti,P.,Di Bussolo,V., Favero.L . \l rrKotsuki, H., Ohishi, T., Inoue. \1.. KqF r2Song,C.8., Shim, W.H., Roh. E.J . Ctn rrTsuchimoto,T., Maeda,T., Shiraltarr I ''Kajiro, H., Mitamura, S., Mori. A . Hrl; r5Suzuki,T., Watahiki,T., Oriyama. T l.I

Huang,X., Wang,J.-H..SC30,301rlCrI rHuang,X., Wang,J.-H.St 560(2ffi' 'Krief, A., VanWemmel, T.. Redon.\l . D

Selenium

r :::. Ii)rmation of hydroxYaryl-

p-.. $rth isobutyraldehydewhile ::: n{rl\obutyratesare the major r "..:cnrdesand 3-butenolleadsto r;r 'ncning by an intramolecular f, -.:-.,rndfive-memberedrings.rt) 1 l

'Akiyama, T., Iwai, J., Sugano,M. 255,7499 (1999). 2Manabe,K., Kobayashi,S. SI 547 (1999). 3Tian,H.-Y., Chen,Y-J., Wang, D., Zeng,C.-C., Li, C.-J. TL41,2529 (2000). alautens,M., Ouellet,S.G.,Raeppel,S. ACIEE 39,4079 (2000). sKobayashi,S., Busujima,T., Nagayama,S. SL 545 (1999) 6Anderson,J.C.,Peace,S., Pih, S. SL 850 (2000). THuang,T., Li, C.-J. TL 41, 6715 (2000). nGillespie,K.M., Munslow, I.J., Scott,P. TL 40,9371 (1999). ezhang, W.-C., Li, C.-J. T 56,2403 (2ffi0). 10Crotti,P, Di Bussolo,V, Favero,L., Macchia, F., Pineschi,M., Napolitano,E. f 55, 5853 (1999). lrKotsuki, H., Ohishi, T., Inoue, M., Kojima, T. S 603 (1999). r2Song,C.8., Shim, W.H., Roh,8.J., Choi, J.H. CC 1695(2000). lrTsuchimoto, T., Maeda, T., Shirakawa, 8., Kawakami, Y. CC 1573 (2000). 'uKajiro, H., Mitamura, S., Mori, A., Hiyama, T. BCSJ 72,1553 (1999). r5Suzuki,T., Watahiki,T., Oriyama,T. TL 41,8903 (2000).

Scandium(Ill)

tris(perfl uoroalkanesulfonyl)methides.

Debenzylationr

Benzyl ethers, N-benzylamides,

and benzyl ester(s) are efficiently

cleaved by catalysis of Sc(CTfj)3.

r

Frtedel-Crafts

-

acylation.2

Scandium tris(perfluorobutanesulfonyl)methide

tipurpose catalyst. Besides promoting

,ao, E:r- .irc adequatealkYl donors tn i- :r. catalyst.It has also been lt- ., rccvclablesYstemfor arene p. .i rth l-phenylalkynes.Triflates p .:' .r proximal Position are hYrl"- :Sc(OTf)r.

Diels-Alder

Friedel-Crafts

reaction and Meerwein-Ponndorf-Verlev

is a mul-

reactions, it is also useful in the reduction.

rlshihara,K., Hiraiwa, Y., Yamamoto,H. St 80 (2000). 2Nishikido,J., Yamamoto,F., Nakaiima,H., Mikami, Y, Matsumoto,Y., Mikami, K. Sf 1990 (1999).

Selenium. 18, 318; 20, 337 Alkenylselenium compounds. Selenium is easily inserted into the C-Zr bond of alkenylzirconocenederivatives. The products can be oxidized to dialkenyl diselenidesror acetylated.2 Selenidesand diselenides.t By manipulation of reaction conditions it is possible to prepareeither RSeR' or RSeSeR'.

3 ) ,OH

RX BuLi

+ 2Se

-

BuSe-SeLi +

BuSe-SeR

I err-i

Y

R'X

2 BuSeLi

t'\---\t

:F af -l

I:

BuSeR'

I >-oH

:c using methallyl(l-butYl)di-

rHuang,X., Wang,J.-H.SC30,301(2000). rHuang,X., Wang,J.-H.SL560(2000). rKrief, A., VanWemmel,T., Redon,M., Dumont,W, Delmotte,C. ACIEE38,2245(1999\.

Silica gel

Selenium-carbon monoxide. Ureas,' Nitroarenes undergo reductive carbonylation and the in situ trapping with unhindered secondaryamines leads to unsymmetrical ureas. Indoles.z 2-Nitrostyrenes afford indoles in the Se-catalyzed cyclization. The substratesinclude 2-nitrostyrene itself and various ct- and p-substituted homologues.

R

Se/CO Et3N - DMF

Itoh.A., Kodama.T.. Masakl.\'. 5f .r rDas,B., Venkataiah, 8., Madhusudl 'ltoh, A., Kodama, T.,Inagaki.S..\tr 'Baptistella, L.H.B.,Sousa, I.N|.O..Cr 'lwasawa, N., Sakurada. F..Iwamorol

100.

R = H .A r . . . . R ' = H . M e .. . .

rYang,Y, Lu, S. ?L 40, 4845(1999). 2Nishiyama, (1999). Y.,Maema,R., Ohno,K., Hirose,M., Sonoda, N. Zt 40, 5'71'7

Silicon tetrafluoride. 3-Fluoroalkanols.t Oxerarcs propargylic are opened by SiF. rr

additives. For example, good resu reaction seems to be suppresscdI promotingepoxideopening.

Silica gel. 15, 282: 18, 3 I 9; 19, 303-304; 20, 338-339 Selective reactions. Desilylation of triethylsilyl ethers in the presence of t-butyldimethylsilyl ethersis accomplishedwith a mesoporoussilica in methanolat room temperature.r Selective esterification of nonaromatic carboxylic acids using NaHSOa-silica in methanolhasalsobeendescribed.2 Oxidations. Photochemicaldegradationofa-hydroxy acids and phenylaceticacid derivatives(oxidativedecarboxylation)rtakesplacein the presenceof a mesoporoussilica. With acidic potassiumdichromate adsorbedon silica-zirconia,regioselectiveallylic oxidation is achieved.oThis reagentis better than CrO:-3,5-dimethylpyrazolefor oxidation of 1-menthenederivatives becausethe 3-keto products are largely absent.

f , )

R

Glycosylfluorides.2 Gllcals I tion of SiFaand an oxidant suchas acetate(HzO). In suchcases.a hnr

Fluorination.t Fluorinarron r SiF.,.The reagentcombinationals varenes. K2Qr2O7l ZrO2-SiO2

Ph

Diels-Alder reaction. Adsorption on silica gel of certain alkyne-Co2(CO)6 complexes that possessdiene and dienophile units separatedby a suitable distance serves to shift the equilibrium toward their cycloadducts, as compared with that in solution.5

Shimizu,M., Kanemoto,S., Nakah.rn :Shimizu, M., Nakahara,Y, Yoshrotr 'Tamura, M., Takagi,T., Quan. H.-D . !

Silicon tetrafluoride

'l:r: 1 rnd the in situ traPPingwith Sr ,.itrlvzed cyclization. The subhomologues. I .: -.ri-,.tituted

R' z

'-v-\

|\ , : . - A N >-R

lItoh,A., Kodama, T.,Masaki,Y. SL35'7(1999). 2Das,B., Venkataiah, B., Madhusudhan, P SL 59 (2000). 3ltoh,A., Kodama, T., Inagaki,S.,Masaki,Y. OL2,33l (2000). aBaptistella, L.H.B.,Sousa, I.M.O.,Gushikem, Y, Aleixo,A.M. ?4 40,2695(1999). 5lwasawa, N., Sakurada, F.,Iwamoto,M. OL2,871 (2000).

H

Silicon tetrafluoride. 3-Fluoroalkanols,t Oxetanesin which one of the o-positions is benzylic, allylic, or propargylic are opened by SiFa regioselectively. Also, the ring opening is influenced by J o . 5 7 l 7( 1 9 9 9 ) .

additives. For example, good results are obtained in the presenceof BuaNF, whereas the reaction seems to be suppressedby diisopropylethylamine-water, which is effective in promotingepoxideopening.

l!

i J::r.r\ in the Presenceof t-butylr, ,. .rlrca in methanolat room temrr-'. '.r1ic acids using NaHSOa-silica d: , , .rcidsand phenylaceticacid deh. :':..cnce of a mesoporoussilica. allylic ..,.1-./rrconia,regioselective lrt , : r-dimethylpyrazolefor oxidarr ... r. rre largelYabsent.

9r

t )

F. SiFa- Me2S + Et2O 0"

z-OH

,Y )

R

R

Glycosylfluori.des.2 Glycals are transforrnedinto glycosyl fluorides with a combination of SiFoand an oxidant such as 1,3-dibromo-5,5-dimethylhydantoin, phenyliodine(IIf acetate(HrO). In suchcases,a bromine atom or a hydroxyl group is also introduced. Fluorination.3 Fluorination of arylalkenes with xenon difluoride is enhanced by SiFa. The reagent combination also transforms aromatic aldehydes into difluoromethoxyarenes.

Ph P{-

SiFa- XeF2

;*;

Phr,/-F

pAr 7lYo

e . : .crtain alkYne-Co2(CO)ucomu:::.i hr a suitabledistanceseryesto r.::r:'rrcdwith that in solution.5

rShimizu,M., Kanemoto,S., Nakahara,Y. H 52, 117 (2000). rshimizu, M., Nakahara,Y., Yoshioka, H. JFC 97 57 (1999') , 'Tamura, M., Takagi, T., Quan, H.-D., Sekiya, A. JFC 98, 163 (1999).

Silver carbonate

Silver. Claisen reanangement.\ Together with KI in acetic acid, silver effects Claisen rearrangementof allyloxyanthraquinones. rSharghi, H.,Aghapour, G. JOC 65,2813(2000).

Silver acetate. Cycloaifulitions.t 1,3-Dipolar cycloadditions of isocyanoacetic esters are catalyzed by AgOAc. In the absenceof dipolarophiles, the estersdimerize to give imidazole-4-carboxylic esters.

P a l e ,P , C h u c h e I, . E J O C l 0 l 9 r l 0 0 l , rGyollai, V., Somsak,L., Szilagyi. L. n. I 'Hauser, F M . , Y i n , H . O L 2 . 1 0 4 5t l m ) ,

MeOOC AsoAc

MeOOC

^

+

cN^cooMe

>

\: N.4eCN

/-] \*'^cooMe H

I t

:

Silver nitrate. 18,320; 19,305--106.i

Cyclizatinn.t 2-Alkynylbenzorc Substitutedisocoumarinsare the malc

Carbonyl compounds from a4llir the a-amino nitrile derivativesof enel drolysisof the products.2

rGrigg,R., Lansdell,M.L, Thornton-Pett, M. Z 55, 2025(1999).

Silver carbonate. 2-Methylenetetrahydrofurans.t 4-Alkynols cyclize on exposure to silver carbonate. An oxygen functionality at the propargylic position has a remarkable acceleratingeffect.

-

-N'

LDA

t{c.

+

. :

Nc'a

I

\

/-o'

ry

BuCHO .zu::-,2:-

q

Ag2CO3 PhH 80'

Barbier reactian,3

A catalvtic am

action of benzylic halides with ArCHO

l-Amino sugars.z Displacement of an anomeric bromine atom by an acetamino group is achieved when glycosyl bromides are treated with silver carbonate in MeCN in the dark.

AcO

aOAc

nco\9$-coNH2 ncd A.

AcO aOAc As2co3 > nco$-\,.o' MecN ncd ,l,ro. 76Yo

Oxidation.r

Oxidation of a naphthol can go beyond the quinone stage.

tbrmed.

rBellina,F., Ciucci, D., Vergamini.P.. Rml r P i e r r e ,F . ,E n d e r s D , . fL40.5301 11999, 'Bieber, L.W., Storch,8.C., Malvestrrr.I . ,l

Silver(I) oxide. 18, 321; 20, 341 Coupling of l-alkynes.t The ft alkenyl and aryl halidesin THF ar (fl, 1 tivator.The salts.BuoNX (X : OH. Fr

rMori, A., Kawashima, J.. Shimada. T. S (2000).

Silver(I) oxide

r:- .r.rJ. silver effectsClaisenre-

Ag2C03- Et3N cH2ct2 25.

*r ..rfltrscetic esters a.fe catalyzed , .:.::rcrize to give imidazole-4-car-

rPale,P, Chuche,J. EJOC 1019 (2000). rGyollai, V., Somsak,L., Szilagyi, L. TL 40,3969 (1999). ' H a u s e rF , . M . ,Y i n , H. OL2,1045 (2000).

t,':.]OC

L-

/ \ \N'^cooMe H

Silver nitrate. 18,320;19, 305-306; 20,340 Cyclization.t 2-Alkynylbenzoic acids afford lactonesby the action of AgNO1. 3Substitutedisocoumarinsare the major products. Carbonyl compoundsfrom a-amino nitriles. A synthesisofct-hydroxy enonesfrom the a-amino nitrile derivativesof enals startsfrom alkylation with aldehydesand the hydrolysis of the products.2

'r c\posure to silver carbonate' , rrrarkableacceleratingeffect.

.) -N'

*"-\Z-

=-,O\

LDA

AgNO3

BUCHO

THF - H2O

83% overall

'a7 o 99o/o

ri

-:,'rnine atom bY an acetamino .,.'h rilver carbonatein MeCN in

-,1 i

aOAc

{-o ^rl - *-7--5''v'' I n^X auv NHAc 760/o

rn.: :hc qulnone stage.

OH

Barbier reaction.r A catalytic amount of AgNO. is important in the Zn-mediated reaction of benzylic halideswith ArCHO in buffer solutions(pH - l2) as lessbibenzylsare formed. rBellina,F.,Ciucci,D., Vergamini, P.,Rossi,R. 7 56,2533(2000). rPierre,F.,Enders, D. TL 40,5301(1999). 'Bieber,L.W, Storch,8.C.,Malvestiti, I., daSilva,M.F.f4 39,9393(1998).

Silver(I) oxide. 18, 321; 20, 341 Coupling of l-alkynes.t The Pd(0)-catalyzed reaction of terminal alkynes with alkenyl and aryl halides in THF at 60" proceedsin good yields when Ag,O is added as activator. The salts. BU4NX (X : OH, F) have similar effects. lMori, A., Kawashima, J., Shimada, T., Suguro,M., Hirabayashi, K., Nishihara,Y. OL 2,2935 (2000).

Sodamide

Silver tetrafluoroborate. 13,273-27 4; 18, 322 Cleavage of S-(2arimetfulsilyl)ethyl group.t Facile Ag(I)-mediated S-C bond cleavageis the basis for the use of the TSE group in thiol protection. The TSE-substituted thioglycosides are stable toward most reagents for carbohydrate transformations except the very strongly hard and soft Lewis acids and desulfonylating conditions, therefore their many applications can be envisaged. rGrundberg, H., Andergran,M., Nilsson,U.J.TL 40,1811 ( 1999). Silver tosylate-urea, Allylntion.t Silver tosylate is used in combination with urea, a Lewis base catalyst, to promote allylation of aldehydeswith allyltrichlorosilane. rChataigner, L, Piarulli,U., Gennari, C.TL40,3633(1999).

Desilylatian.2 The C-Sr I an aryltrialkylsilane suffers ro ammonia.

rChoppin, S.,Gros,P, Fon.\'. 5('. :Sun,G.-R.,He,J.-8.,Jie.H.-J..h

Sodium 13, 277; 18, 323--31{. Aromatic acylation.t .,\n , aromatic hydrocarbon such as boxylic ester in THF at room t DMF are used. Desulfunylation.2 A gena naphthalenide(Na + naphthala

Silver trifluoromethanesulfonate. 13, 274-27 5; 14,282-283; 16,302; 17,314; 18, 322-323; 19, 306; 20, 342 N-Alkylation.t Silver triflate is essentialfor an intramolecular alkylation of oxazole that contains an aziridine moiety. A I,3-dipolar cycloaddition is triggered henceforth.

OAc

OTBS AgOTf / N.4eCN

o

rPeriasamy, M., Reddy,M.R..Bh.i rBergmeier, S.C.,Seth,P.P.fL {0. (

'( )**" ( I

'Vede.is, 8., Klapars, A., Naidu,B.N.,Piotrowski, D.W.,Tucci,F.C."/ACS122,5401(2000). Sodamide.20,342 Alkylation.t Allyl phenyl sulfide undergoes alkylation using DME-activated sodamide.The processis adaptableto a synthesisof phenyl 1-vinylcycloalkyl sulfidesby a twofold alkylation with 1,rY-Ph 65%

is by s.r.1. of indole-3-acetonitrilesrs : : \ubstituted indoles are conveniently F .'.:hBurNF.'n r. ..- tirnyl) arylamines lose one of the r'relic disulfidesare obtainedfrom l,

Partial

hydrolysis,t

hydroxide.

20, 359

The partial hydrolysis

of dimethyl

esters can be achieved by

usingdry BuaNOHin THF or DME. rHasegawa, H. SL 84 (1999). T.,Yamamoto,

Tetrabutylammonium nitrate-trifl uoroacetic anhydride. Nitration.t This reagent system nitrates l-deazapurine nucleosides.The regioselectivitydependson existing substitutionpatterns. lDeghati,P.Y.F., M.J.,Koomen,G.-J.TL4l,569(2000). Bieraugel, H., Wanner,

Tetrabutylammonium peroxydisulfate, 19, 322 C:0 regeneration. Oximesl and semicarbazones2are cleaved. Oxidations, Benzyl ethers are removed by oxidation with (BurN)zS2Os and alcoholysis3.Primary amines are oxidized to nitriles with Ni-Cu formates as catalyst.a Oxidative cyclaadditian.5 The oxidation of l,3-dicarbonyl compounds in the Dresenceof cvclic enol ethersleadsto fused acetals.

410

Tetraethylammoniurn hydrogen carbonate

'Chen, F., Liu, A., Yan, Q., Liu, M., Zhang,D., Shao, L. SC 29, 1049 (1999). 2Chen, F., Liu, J.-D., Fu, H., Peng, Z.-2., Shao,L.-Y. SC 30, 2295 QUn). 3Chen, F., Peng,Z.-2., Fu, H., Meng, G., Cheng, Y., Lu, Y.-X. 5L627 (2000). aChen,F., Peng,Z.-2., Fu, H., Liu, J.-D., Shao,L.-Y. JCR(S)726 (1999). 5Chen,F., Fu, H., Meng, G., Cheng,Y., Hu, Y.-L. S 1091 (2000).

Tetraethylammonium peroxydicarbc Oxazolidin-2-ones.1 This reagc'n Et4NClOl, CO2, and 02. It carborrle cyclizationto oxazolidin-2-oneson iunl

rFeroci,M., Inesi,A., Muccianti.y.. ft1x.r [. Tetrabutylammonium tribromide. Ether cleavage.r BuaNBrj in methanol cleaves several kinds of ethers but TBS ethers are the most susceptible. Thus, desilylation can be achieved in the presence of acetonidesand THP ethers. rGopinath, R.,Patel,B.K. OL2,4177(2000).

i

?

Tetrabutylammonium triorganodifl uorostannates. Diarylmethanes.t With (PhjP)4Pd as catalyst, unsymmetrical ArCH2Ar' are obtained from a cross-coupling reaction between aryl triflates and BuqN[BnrSnFz] in DMF. Disulfides.z BuaN[RjSnF2] act as nucleophiles toward sulfur. Oxidative dimerization of the thiols initially formed, results in disulfides.

Tetrakis(acetonitrile)copper(I ) hexefr Cyclic imines.r Alkynylamine. cr Diaryl ethers.2 The phenol-anl (MeCN)aCuPF6.

Epoxidation.3 Conversionof alkcn ascatalystproceedsat low temperatureI c

rMuller,T.E.,Grosche, M., Herdtweck. F- P Kalinin,A.V.,Bower,J.F.,Riebel.P. Snros 'Andrus. M.B..Poehlein. B.W.Il 41. lri:: '

Tetrakis(triphenylphosphine )palledit 16,3 17-323: 17, 327-33 | : 18, 3{7--U9

rMartinez, A.G.,Barcina,J.O.,delR.C.Heras,M., deF.Cerezo, A. OL2, 1377(2000). 2Kerverdo, X., Poulain,S.,Gingras, M.TL41,5841(2000). S.,Femandez,

Allylic displacements. Neu trp substitutionare B-allyloxyacrylicc':rc'r carbonatesand sulfonatescontainherrc Regioselective displacement of allr lx

Tetrachlorophthalimide. Primary amines.t When used in the Mitsunobu reaction, the litle compound converts primary and secondaryalcohols into the conesponding protected amines.

allylsilanes.2Allenyonitriles are obtarncrlt

tlia,ZJ., Kelberlau, S.,Olsson,L., Anilkumar,G.,Fraser-Reid, B. SL 565(1999).

Tetracobalt dodecacarbonyl. Pauson-Khand reaction.t With cyclohexylamine as activator, catalytic amount of Coa(CO)12mediatesthe Pauson-Khand reaction in DME under CO. rKrafft,M.8., Bonaga,L.v.R.ACIEE 39,3676(2000).

Tetraethylammonium hydrogen carbonate. 20, 360 Carbonates.t Treatment of 1,2-diols with Et4NHCOT in MeCN at room temperatureresults in the formation of cyclic carbonates. Sulf.des.2 EI4NHCOj or (EtaN)2COjcan serve as basein the alkylation of thiols. rCasadei, M.A.,Cesa,S.,Feroci,M., Inesi,A. NIC 23,433(1999). 2Feroci, M., Inesi,A., Rossi,L. SC29,2611(1999).

t(

, t*

n_*R,, ocooR

Displacementthat is followed hr cr,

1-hydroxyalkyl-1-lactones.5 Thndem coupling and cvcli/ir c-arylvinylated cyclopropanes6 and trt andoxazolidinones." Furanderivatrrc.r

6\o tl C,rHru/

+ Ptrl

Tetrakis(triphenylphosphine)palladium(0)

4tl

Tetraethylammonium peroxydicarbonate. Oxazolidin-2-ones,t This reagent is available from electrochemical reaction of EqNClOl, CO2, and 02. It carboxylates 2-amino alcohols and the products undergo cyclization to oxazolidin-2-ones on further treatment with TsCl.

( :e r()19( 1999). P l:q: (1000). '-\ .i 627(2000). -th il9g9). f., - ' r t

rFeroci, V, Rossi,L.TL40,6059(1999). M., Inesi,A.,Muccianti,

r.. .c'\erll kinds of ethers but TBS n . i:l he achievedin the presence of

Tetrakis(acetonitrile)copper(I) hexafl uorophosphate. Cyclic imines.' Alkynylamines cyclize under the influence of (MeCN)aCuPF6. Diaryl ethers.2 The phenol-aryl halide coupling is promoted by Cs2COj and (MeCN)+CuPFc. Epoxidation.3 Conversionof alkenesto epoxideswith MCPBA, using (MeCN)aCuPF6 as catalystproceedsat low temperature(e.g., -20').

!5.

a.!.:. unsymmetricalArCH2Ar' are r:-. .:r\l triflates and BuaN[BnjSnF2] s ' .r,ird sulfur. Oxidative dimerization

\ OLz. 1377(2000)Cr-: < \ J t (2000). [ {r

lMuller,T.8.,Grosche, 8., Pleier,A.-K.,Walter,E.,Yan,Y-K. OM 19, 170(2000)M., Herdtweck, rKalinin,A.V, Bower,J.F.,Riebel,P, Snieckus, v. JOC 64,2986(1999). rAndrus. B.W.TL4l, l0l3 (2000). M.B..Poehlein. Tetrakis(triphenylphosphine)palladium(0). 13, 289-294; 14' 295-299; 15' 300-304; 16. 3 11 -323 : l7 . 327-33 | : 18, 347-3 49 ; 19, 324-33 | : 20, 362-3 68 Allylic displacements. New types of substrates for this (Ph1P)aPd-catalyzed substitutionare B-allyloxyacrylicestersand p-allyloxyvinyl sulfones.rThese vinylogous carbonatesand sulfonatescontainbetterleaving groups. Regioselectivedisplacementof allylic acetatesthat contain a homoallylic silyl group gives are obtainedby reactingpropargyl carbonateswith Me]SiCN.r allylsilanes.2Allenyonitriles

L(-: .u reaction, the litle compound ;, :::.ponding protectedamrnes. R-'

r i. .: u. Sr 565(1999).

R \

q,, ocooR

h:. :rl lrs activator, catalytic amount of I I ) \ 1 F -u n d e r C O .

' R (Ph.P)4Pd> R + Me3si_cN Fc{ rHF ^ Nc

at room

/'\n i l -

FL-:ti.r.

n: .i. basein the alkylation ofthiols. 3ri

..)99).

R-

Displacementthat is followed by cyclization enablesthe synthesisof chromenesaand l-^y-lactones.' 1-hydroxyalky Tandem coupling and cyclization. Functionalized allenes are converted to and heterocyclesincluding epoxides,Ttetrahydrofurans,E cr-arylvinylatedcyclopropanes6 Furanderivativesare formed from allenyl ketones.l0 and oxazolidinones.')

:h

rr:. F-I.NHCOr in MeCN

'

+Ph-l

(Ph3P)4Pd .------------------*

tn\-

/ \\ ^t;in,l'#.'c''H"404

CtzHzs 75%

4t2

Tetrakis(triphenylphosphine)palladium(0)

In the presenceof sodium alkoxide (for generating alkoxyimino nucleophiles for the cyclization), 2-alkynylbenzonitriles afford isoindole derivatives.| | Cyclizations and cycloadditions. Treatment of N,N'-diacylhydrazinesl2 and "y,6-unsaturated ketone O-pentafluorobenzoyloximesrr with (Ph.P)+Pdgenerates1,3,4oxadiazolesand substitutedpyrroles,respectively.

N

'ococ6Fs

(Ph3P)4Pd Et3N / DtVtF

pn)*

A [4 + 2]cycloadditionbetweenenynesand 1,3-diynes,with the latter serving as the two-carbon component,results in substitutedbenzenederivatives.The adductsderived from 1.4-di-l-butoxv-1.3-butadivne are readilv convertedto coumaranones.ra

I ) )

+

l

+ rPh ,^/*NHR

2 2 ,;i

z>zy\sna" (.o-*\.,/ | ll l" l

>:F .-':Dvs:

N1-'N'N-"\

93%

Addition to alkynes. Nucleophiles add to alkynes in different addition modes. are Thus, c-substituted vinylphosphonium saltsr6 and 1,2-diphosphonylalkanesrT prepared from 1-alkynes,but apparently an isomerization-hydroaluminationpathway prevails when 2-alkynes react with amines under similar conditions.The products are allylamines.r8(Note the formation of N-benzyl-2-styrylpiperidinein an intramolecular reaction,but the correspondingN{osyl derivativefails to cyclize.)

(-F*

Tetrakis(triphenylphosphine)palladium(0)

ai :ri .rlkoxyimino nucleophilesfor the II k' .:::rr atives. c:" , 't N.N'-diacylhydrazines12and *ith (Ph.P)rPd generates1'3'4r.-.

ph'V.\\$runr, / R=rs

+ (Ph3P)4Pd

\':,'o-Q

phZ-""""ttNHR

Bn

, i

-

HN\

r

;

l

l

81%

/

f,h--f,\'/

i ncs. with the latter serving as the - Jcrivatives.The adductsderived .J to coumaranones.la

/Y

rr=a

Acylations. 2-Alkynoic estersare made from l-alkynes and a chloroformic ester in the presenceof (PhiP)aPdand base(DMAP-1,2,2,6,6-pentamethylpiperidine)'re Stille coupting. The usefulness of tosylates in the Stille coupling facilitates preparation of arylcoumarin inhibitors of gyrase 8.20 Benzylic and allylic boronates are I readily obtained from RSnBuj and bromomethylboronates.2 The Stille coupling is acceleratedby CuCl. An effective system applicable to sterically congestedsubstrateshas been developed.22Preparationof functionalized dienesby homousing slightly different conditionsenablescompletion of a coupling of alkenylstannanes ( of )-wodeshiol.r' synthesis

o'/:-

?'

1

/..

91Yo

{Ph3P)4Pd> ..\3;\t"utt'

o''

I

ll

*

I

o"^"^J-..ttu'" bu3r,, I

ricr_cucrI

ll

I

I

95% (93% ee)

h \le,SiCN and then N-allYlation

o ) o

OH (Ph3P)4Pd>

CN

/- ' : .-rZ: ru. - N,f.f

O-4\Sne'.

(oJ=/

ll

P

:',"1"":::\o 82%

l1

93o/o

t,

f.\ncs in different addition modes. are .::rJ 1.2-diphosphonylalkanesrT pathway . :: zation-hydroalumination

.:rlrlar conditions.The products are . l - rr rr lpiperidine in an intramolecular .. to cyclize.) r( d,

(Yo., (-)-wodeshior

(o)""gd

Ho,"n,'oH

(ori)""to' 'o^'-/

Tetrakis(triphenylphosphine)palladium(0)

1-Alkynes are convertedto (E)-alkenesin a microwave-assisted hydrosilylation-Stille coupling process,2aand both reactions are catalyzed by (PhjP)aPd.Interestingly, arylation oftributylstannylacetylene is achievedvia a Stille coupling and then C-stannylation.25

Bu3Sn:

+ Ph-l

Ph:

##

+ Bu3Sn-l11-

T\e 2-azabicyclo[3.3.I ]nonane f accessiblefrom an intramolecular ccr Organobismuth dialkoxides cor.rp

pn-----sngu. 83%

_ R +

E( Stille coupling betweenRSeSnBuj and R'X is applicableto the synthesisof diorganyl selenidesRSeR'.26 Suzuki coupling, A practical transformation of ArX to ArMe is by the Suzuki coupling with [MeBO]..2? Diarylmethanes are obtained from ArCH2Br and arylboronic acids.28 The coupling of 3-pyrrolin-3-yl triflates with arylboronic acids leads to 3-arylpyrroles becauseof concurrentdehydrogenation.2e A caveatof the coupling involving haloanilines is that deamination30 also occursto someextent. A route to alkynylarenes and enynes from l-alkynes involves formation of alkynylboronic esters flithioalkynes * (r-PrO)rB] and Suzuki coupling in situ.:rrSuzuki cross-couplingusing thallium(I) ethoxide32 as promoteris superiorto TIOH becauseof its stability, commercial availability, and easeof use. A convenientmethod for assembling conjugatedpolyenesis assured.

A testimony to the efficiencl of , Pd-catalyzedreactions is delineatedr

,-Rr il It

+

(1) +

-a' r- l"n -

(1) = (Ph3P)aPd

COOMe - TtOEt (Ph3P)4Pd

t-BUOOC

THF - H2O (3 i 1)

tBuOOC

(Ho)28'V\y'2..v.oH

-J

I-BUOOC

97%

In a two-stagecoupling of N-allyl-N-2-bromoallylamine,the N-sulfonyl derivatives are most suitable as B-elimination of alkylpalladium intermediates after the initial (likely by coordinationl.t' intramolecularHeck reactionis suppressed The coupling of arylboronic acids with acid chlorides is the basis of a ketone synthesis.ra It is found that the Suzuki coupling in an ionic liquid has severaladvantages: reducedcatalystconcentration,no homocoupling,and reactionin the air.ts Other coupling reactions. A model study has demonstrated the utility of intramolecular Heck reaction in the construction of the morphine skeleton.l6 It is surprising that only the desirableregioisomer is formed.

F--

Tetrakis(triphenylphosphine)palladi,,m(0)

r . . - .\ .t\ e-assistedhydrosilylation-Stille Z . :

^

., Ph,P)1Pd.Interestingly,arylation :.lrns and then C-stannylation.2s

415

The 2-azabicyclo[3.3.1]nonaneframework, a portion of the strychnos alkaloids, is accessiblefrom an intramolecular coupling of 4-N-(2-haloallyl)aminocyclohexanones.3T Organobismuth dialkoxides couple with electron-deficient aryl and alkenyl triflates.38

LDA

Sn-l +

Ph:SnBu3

Tfo

R.-..-f

(Ph3P)4Pd

83%

NMP 80'

Etooc

| | ) EtOOC""--'J

:- :.eble to the synthesisofdiorganyl I'

: .{rX to ArMe is by the Suzuki

i ' : . : :J liom ArCH2Br and arylboronic

3'

A testimony to the efficiency of constructing highly unsaturatedcarbon skeletons by Pd-catalyzedreactions is delineated in a synthesisof xerulin.3e

^, 'r()nicacids leadsto 3-arylpyrroles : thc coupling involving haloanilines

^ ----J

)t' a

i-llkynes involves formation of .: Suzukicouplingin situ.rrSuzuki ,: r\ superiorto TIOH becauseof its \ ,r)nvenientmethod for assembling

ll

f

i

)

-

+lJfLn:+ ----J

BrZn.-:-

ll

I

II a u u : (1)= (Ph3P)aPd

| ,r, V "

TBS lrt

l(1) V

'-f\

_

tt_]\ -TBS

__/-:\,, I

'\r,

//--:--:l

___J

97To

r ., . ..rnrine,the N-sulfonyl derivatives lr.:.r .-:n intermediatesafter the initial ^. -,',,rdination).rr u -:ll,rridesis the basis of a ketone I .::.:,'nicliquid has severaladvantages: : i'.rctionin the air.rs r:.r. |(: demonctrated the utility of ,r the morphine skeleton.36It is

|r]

t"t'

:---1\

V

:-3uOOC

l,

l o n ;z n e 2 ;

Itl

: BuOOC

LBt

':1E'5

\:_Br

cp,z(H)cl

r-\:-',. V' +

Tetrakis(triphenylphosphine)palladium(0)

Rearrangements.

Allyl

esters are directly

converted

to isocyanatesaO when the

modified Curtius rearrangementis carried out in the presenceof (Ph.P)oPd.A versatile construction of the core structure of antibiotic CP-263114 is highlighted in a reaction sequenceconsisting ofcarbonylation, lactonization, and siloxy-Cope rearrangement.al

co

-

(Ph3P)4Pd

i-P12NEt / PhCN

bothZlEisomers useful

R

JEt3sio

46-56%

rEvans,P.A., Brandt,T.A., Robinson,J.8.TL40,3105 (1999). 2Macsari,I., Hupe,8., Szabo,K.J. JOC 64,9547 (1999). iTsuji, Y., Taniguchi,M., Yasuda,T., Kawamura,T., Obora,Y. OL2,2635 (2000). aNay, B., Peyrat, J.-F., Vercauteren,J. EJOC 2231 (1999). sRudler, H., Parlier, A., Cantagrel, F., Harris, P, Bellassoued, M. CC'17 | (2000). 6Ma, S., Zhao, S. OL2,2495 (2000). ?Ma, S., Zhao, S. JACS 121, 7943 (1999). 8Kang,S.-K., Baik, T.-G., Kulak, A.N. 5L324 (1999). 'Kang, S.-K., Baik, T.-G., Hur, Y. 255,6863 (1999). roMa, S., Zhang, J. CC 117 (2000). "Wei, L.-M., Lin, C.-F.,Wu, M.-J. TL 4l,1215 (2000'). I2lutun, S., Hasiak,B., Couturier,D. SC 29,111 (1999). rrTsutsui,T., Narasaka,K. CL 45 (1999). 'oGevorgyan,V, Quan, L.G., Yamamoto,Y.JOC 65,568 (2000). r5Gyoung,Y.S.,Shim, J.-G.,Yamamoto TL 41,4193 (2000). ,Y r6Arisawa, M., Yamaguchi, M. JACS 122,238'7 (2O0O). r T A l l e nJ, r . ,A . , M a n k e ,D . R . ,L i n , W . T L 4 l , l 5 1 ( 2 0 0 0 ) . rsKadota,L, Shibuya, A., Lutete, L.M., Yamamoto, Y. JOC 64,4570 (1999). reBottcher, A., Becker, H., Brunner, M., Preiss, T., Henkelmann, J., DeBakker, C., Gleiter, R.JCS(Pr)355s(1999). 2{)Schio, L., Chatreaux,F., Klich, M. TL 41,1543 (2000). 2rFalck,J.R.,Bondlela,M., Ye, J., Cho, S.-D. TL 40, 5647(1999). 22Han,X., Corey, E.J. JACS l2l,7600 (1999). 2rHan, X., Corey, E.J. OL l, 187| (1999). 2aMaleczka, Jr., R.E., Lavis, J.M., Clark, D.H., Gallagher,W.P.OL2,3655 (2000). 25Antonelli,E., Rosi, P.,Sterzo,C.L., Viola, E. JOMC 578,210 (1999). 26Nishiyama,Y., Tokunaga, K., Sonoda, N. OI 1, 1725 (1999). 27Gray,M., Andrews, I.P., Hook, D.F., Kitteringham, J., Voyle, M. TL 41, 6237 (2000). 28Chowdhury S., Georghiou, P.E. TL 40,'1599 (1999). 2el-ee,C.-W., Chung, Y.J. TL 41,3423 (2000).

r0Hird,M., Seed,A.J., Toyne,K.J. Sl {-rt 'r Castanet,A.-S., Colobert, F., Schlmarn ' 'rFrank, S.A., Chen, H., Kunz, R.K.. i-in

rrLee, C.-W, Oh, K.S., Kim, K.S...{hn- X IHaddach, M., McCarthy,J.R. IL $. -rl( '5Mathews, C.J., Smith, P.J.,Welton. T Cr '6Frey, D.A., Duan, C., Hudlicky. T. OL l. rTSole,D., Peidro,E., Bonjoch, J. OL 2. : rNRao,M.L.N., Shimada,S., Tanaka.\l ( reNegishi,E., Alimardanov,A., Xu. C Ot '"Okumoto, H., Nishihara, S., Yamanxro. 'rBio, M.M., Leighton,J.L. OL 2. 2905, 2

Tetrakis(triphenylphosphine)pelli Coupling reactions. c-Fluorrn virtue of their capacity of partakrng r based on the Pd(0)-catalyzed erct followed by the Negishi coupling :

1,2-Alkadien-4-ynesare fornrcd b with 1-alkynes.3

""" *",r(

*

\

'Chen, C., Wilcoxen, K., Zhu. Y.-F..KrmrDabdoub,M.J., Dabdoub,V.B., Manm.. 'Condon-Gueugnot, S., Linstrumelle. G I

Tetrakis(triphenylphosphine )pbttr Hydrosilylation. This reacuoo complexes such as (PhrP)1Ptor radrc

Dib oratio n of methy le necyc Iq opening of the substratesoccurs oo can be transformed in various * ar s tr

Tetrakis(triphenylphosphine)platinum(0)

when the . :.rc'ft€d to isocyanatesa0 (:: nrcsenceof (Ph3P)4Pd. A versatile :P-:hrll-l is highlightedin a reaction n .::1.:.lloxy-cope reiurangement.4l

\

-

l

I

:

= *^l

l

Et3SiO

417

3oHird,M., Seed,A.J., Toyne, K.J. SZ 438 (1999). 3rCastanet. A.-S., Colobert,F., Schlmam,T. OL2,3559 (2000)3zFrank.S.A., Chen,H., Kunz, R.K., Schnaderbeck, M.J., Roush,W.R. OL2'2691 (2000)' 3 r l e e . C . - W . .O h , K . S . ,K i m , K . S . ,A h n , K . H . O L 2 , 1 2 1 3 ( 2 0 0 0 ) 34Haddach, M., McCarthy,J.R. Zt 40, 3109 (1999). rsMathews, C.J., Smith, P.J.,Welton, T. CC 1249 (2000). r6Frey,D.A., Duan, C., Hudlicky, T. OLl,2085 (1999). rTSole,D., Peidro,E., Bonjoch, J. OL2,2225 (2000). r8Rao,M.L.N., Shimada,S., Tanaka,M. OL l, l2'l I (1999). ieNegishi,E., Alimardanov,A., Xu, C. OL2,65 (2000)' loOkumoto, H., Nishihara, S., Yamamoto, S., Hino, H., Nozawa, A.' Suzuki, A' Sf 991 (2000)' arBio, M.M., Leighton,J.L. OL2,2905 (2000).

l 46-56Yo

iodide. 18' 349-350; 20, 369 Tetrakis(triphenylphosphine)palladium(0)-1.n9,r6( 1999).

t \l l'( ) replaces the catecholboryl r: .: :.r()tectedform are obtainedfrom r .. :kup. tO the smooth autoxidation of .a!:.1:.1;

rFenaz,H.M.C., Grazini, M.V.A., Silva, Jr., L.F., Longo, Jr., L.S. SC 29, 1953 (1999)'

Thallium(IlD nitrate,TTN. 16,326;18,351;19,334;20,371 cyclopentyl 2-hyd.roxyalkylketones.t 2-(l-cyclohexenyl)ethanolsundergo nng with TTN in aqHOAc. on treatment contraction

r l' RuCll. Without TEMPO, further !i".::r

rl /\'\oAc

|

r|.

'

419

r(No3)3./\)-\/oH

c'd.

(-)--

c . : .. i n \

allylic alcohols to ketones

*ffi

|

v

H

,P oH y

R=H

71%

R=Me68%

Ring expansion.2 The ring expansion of unsymmetrical l-vinylcyclobutanols shows different regioselectivities as effected by Tl(NOj)j and by (PhCN)2PdC12'

Thionyl chloride-trifl ic acid

:Olah. G.A., Marinez, E.R., Prakash.G.K-S

Thiourea. 19, 336; 20, 37 l-372 Episulfi.des.t In a convenion ol dn(IV)-porphyrin complex, thiourea fu 1,3-Dioxolane cleavage.: Hl& thiourea in aqueous ethanol at rcflr substrates such as 1,2;5,6-di-O-rs acetonideis cleaved.

:Tangestaninejad, S.,Mirkhani,V. SCt. f, : Majumdar,S.,Bhattacharjya , A. JOC g. 5

Thulium(Il) iodide. Tml2(dme)1 is rnct Alkylation.' the reaction of RX with ketones. Il 13

o Tt(N03)3 (PhcN)2Pdcr2

6.3: 1 1 i 7.1

rFerraz, H.M.C.,Santos, A.P.,Silva,Jr.,L.F.,deO.Viera,T. SC30,751(2000). 2Kocovsky, P.,Dunn,V.,Gogoll,A., Langer,V. JOC 64,101( l 999).

1-Thionoacyl 6-nitrobenzotriazoles. Thiono esters.t At room temperature and in the presence of imidazole, the benzotriazolederivatives transfer the RC:S group to alcohols.

must be avoided.

rEvans, W.J.,Allen,N.T."IACS122.I I I t , i

Tin. 13, 298; 17' 333-334;18' 352. 2l Alkylation. The allylating agcl consistsof two species,the initialll- fc Tin in combination with Me.SrO : bromomethylketoneswith aldehldcs rChan,T.H.,Yang,Y.,Li, C.l. JOC6. sj rSun,P.,Shi,B. "/CR(S) 318(1999).

iShalaby, M.A., Rapoport, H. JOC 64, 1065(1999).

Thionyl chloride-benzotriazole. Chlori.des and nitriles. The reagent combinant transforms alcohols to alkyl chloridesand acidsto acid chlorides,rwhile aldoximesare dehydrated.2

Tin(II) bromide. 14' 303-304: l& -15 With SnBrl as prc Allylation.t regioselectivity and diastereoselectrrr

rChaudhari, S.S.,Akamanchi,K.c. SL 17630999). 2Chaudhari, S.S.,Akamanchi, K.c. SC29, 1741(1999\.

I

\4.,Bt Thionyl chloride-triflic acid. Dinryl sulfuxides.t A Friedel-Crafts-type reaction between arenes and thionyl chloride is catalvzed bv TfOH.

+ PhcHo

;

Tin[D bromide

rOlah, G.A., Marinez, 8.R., Prakash' G'K'S' St 1397 (1999)'

Thiourea. 19,336; 20,37 l-3'12 that is catalyzed by a Episulfides.t In a conversion of epoxides to episulfides atom' tin(Iv)-porphyrin complex, thiourea furnishes the sulfur I,3-Dioxolanecleavage.2Hydrolysisofcyclicacetalsisaccomplishedwith Some selectivity is shown in thiourea in aqueous ethanol at reflux temperature' in which the terminal substrates such as 1,2;5,6-di-O-isopropylidenefuranoses acetonide is cleaved' rTangestaninejad, S.,Mirkhani,V. SC 29,2079(1999)' 2Majumdar, A. JOC 9,5682 (1999)' S.,Bhattacharjya,

:l

Thulium(Il) iodide. in mediating Alkylation.t Tml2(dme)2 is more powerful than SmIz(thflx-HMPA HMPA where situation a in valuable particularly rhe reaction of RX with ketones. It is

v

must be avoided. IEvans,W.J.,Allen, N.T.JACS 122,2l I 8 (2000)'

-

A

\

"^A

Js --Ji._

r . l

le-nitrogen. 20, 380-391 ir. ::r. lbrmation of 2_substituted h,::. To obtain reasonableyields x . .rrlhdrawinggroup.

Reductive couprings'2 Ticlo-BuoNl appears to have similar reactivity as Ticl4-EtjN in effecting reductive coupling of ArCHo. Enolates generatedfrom ct-haloketonesby this reagentundergo aldor reaction with aldehydes, providing predominantrythe syn_rsomer. rTsuritani, T., Shinokubo, H., Oshima,K.TL40,gl2l (19991. 2Tsurirani, T., Ito, S.,Shinokubo,H., Oshima,X..lOi iS', SOIOtZOOOt.

fitanium(IV) iodide

Titanium(IV) chloridezinc. 20, 381 Reductive couplings. Formation of 4,5-diarylimidazolidines from imines is readily effected.l The reagent system for coupling ArcHO to afford syn-hydrobenzoinscontains TMEDA.23 (The complex is prepared from TiCla, Zn, TMEDA, and PbCl2. Note that an alternative complex for the same purpose is derived from TiCla, Mn, MerSiCl, and a Schiff base,but diastereoselectivitydependson the Schiff base.4)

rShimizu,M., Shibuya,K., Ha!aliaslrHayakawa, R., Sahara,T., Shimizu. V 'Mukaiyama, T., Yoshimura, N.. lganC lHayakawa,R., Shimizu, M. Ct 7lJ ,: iHayakawa, R., Shimizu, M. OL 2. rfr-

Titanium

OH

TiClai Schiffbase II

Ph

,nlYtn

,n\'n.

Mn - Me3SiCl

H

OH

N,leCN 25'

OH

13. j

tetraisopropoxide.

18,363-364;19, 346-34'l'.20. -1SI pAmino acid derivatives. i condensation.l

OH (99 : 1) 75%

rLi, J.,Wang,S.,Hu, J.,Chen,W. TL 40,196l(1999). 'Li, T., Cui,W., Liu,J.,Zhao,J.,Wang,Z. CC 139(2000). 3oshiki,T., Kiriyama,T., Tsuchida,K., Takai,K. CL334 (2O0O). aBandini,M.,Cozzi, P.G.,Morganti,S.,Umani-Ronchi, A. fZ 40, 1997(1999).

Titanium(Il) halide-copper. Reductive couplings,t Aliphatic and aromatic aldehydes undergo reductive dimerization on exposureto TiBr2-Cu. pHydroxy carbonyl compounds.2 Aldol and Reformatsky reactions involving debrominative enolization of cr-bromoketones and cr-bromo thioesters with TiCl2-Cu-r-BuCN are readily achieved.Acceptors are limited to aliphatic aldehydes becausepinacol formation by aromatic aldehydespredominatesunder the conditions. rMukaiyama,T., Kagayama, A., Igarashi,K. Cf 336(2000). 2Mukaiyama, T., Kagayama, A., Igarashi,K., Shiina,I. CL ll57 (1999).

Titanium(IV) iodide. Reductions. Chemoselectivereduction of sulfoxides to sulfidesr and a-diketones to a-ketols2employs the title reagentin MeCN at 0'. Aldehydes are dimerized to give l,2-diols (dl- >> meso-)on exposureto TiIa, with or without addingCu.r'a Aldol reactions,5 Methoxyallene oxide forms a titanium enolate on treatment with TiIa. Addition of aldehydesor acetalscompletes the aldol reactions.

o /\

Tict4 +

OMe

RcHo

o o H ,\^. OVe

,//Y'oMe

+

\

NHCOOMe

AUylic displacements. In R pronucleophileson treatment\r'lth I Aldol reactians. A high &E

reaction mediatedby titaniumrl\-r chiral ct-hydroxy acids, :rsymmetrx In conjunctionwith PhrP.rr-P( roalkyl ketones with aldehydes...1 the ketone by (i-PrO)oTi in the \lct

Ph

Fo*

(

t

)

H

rKise, N., Ueda,N. JOC 64,751I r 199 :Poli, G.. Giambastiani.G.. Mordrnr..|" 'Mahrwald, R. OL2,4011 (2000r {Shen,Y., Zhang,Y., Zhou, Y JCS,P i '

fi r-nium tetrrisopropondc

tl::r-r./olldines from iminesis readily ) : .::: 'rti rlrr-hydrobenzoins contains Z: l \!EDA. and PbCll. Note rhat an r.J ::,,m TiCl.,.Mn, Me.SiCl, and a S . : . . : :h l s e . ' t

OH l ' P h - -P: ' ' h

= ( l

:

)-

Shimizu,M., Shibuya,K., Hayakawa,R. SZ 1437 (2000). Hayakawa, R., Sahara,T., Shimizu, M. TL 41,7939 (2C0,O). \lukaiyama, T., Yoshimura, N., Igarashi, K. CZ 838 (2000). 'Hayakawa,R., Shimizu,M. CL724 (2000). ' Hayakawa, R., Shimizu, M. OL 2, 4079 (2000).

Titaniumtetraisopropoxide. 13,3 I 1-3I 3; 14,311-312;15,322;16,339;17,347-348; lE, 363-364;19, 346-347; 20, 381-382 pAmino acid derivatives. (l-PrO)aTiplays a critical role in the Mannich-type condensation.l

oH 39

1)

r

*

\orrae

)

i-Pr2NLi/ THF

\"oo""

-70"

COOMe

NHCOOMe

{r

di:

DJ

431

.-

NHCOOMe

lqqT{1999).

.i)dc-hydesundergo reductive

.{r'r(\rmatskyreactionsinvolving

s ::..1 cr-bromo thioesters with r( ,::i lrmited to aliphatic aldehydes ' P : , : :nlnatesunderthe conditions. {- :e99).

t\-.:r'. t() sulfides'and a-diketonesto ler-. ir. are dimerized to give l,2-diols H::: (-u.'{

Allylic displacements. In Pd(0)-catalyzed reaction, titanates generated from the pronucleophileson treatment with (i-PrO)oTi serve adequately.2 Aldol reactions. A high degree of syn-diastereoselectivityis exhibited in the aldol reaction mediated by titanium(IV) alkoxides in the presence of ct-hydroxy acids. With chiral a-hydroxy acids, asymmetric induction is observed.r In conjunction with PhrP, (i-PrO)aTi promotes condensationof bromomethyl perfluoroalkyl ketones with aldehydes.Allylic alcohols are obtained owing to the reducibility of the ketone by (l-PrO)aTi in the Meerwein-Ponndorf fashion.a

Ph

Fo*

(

Br

Ph - Ph3P (i-PrO)aTi --;"-

FaC

r :::.!ntumenolateon treatmentwith l-.: . r.'actions.

OH

-J*

3Me

syn : anti 3 0 : 7 0 9 2 : 8

no additive + (i-PrO)4Ti

\/-oli'

FsC

90To

'Kise, N., Ueda,N. JOC 64,7511 (1999). zPoli, G., Giambastiani, G., Mordini, A. JOC 64,2962 (1999). rMahrwald, R. OL2,4011 (2000). aShen,Y., Zhang,Y., Zhou, Y. JCS(P1) [r59 0999).

Titanocenebis(triethyl phosphite)

Titanocenebis(triethyl phosphite).20, 383 Desulfurativealkylationand acylation. Titanocene bis(triethylphosphite)promotes desulfurative alkylationof allylic sulfides(dithioacetals) with r-alkylhalides.r

tn-Yt) sJ

?tn Ph#spn

.

The cycloelimination is also ap apparently involving the releasr ol

Z;),.

Cp2TiIP(OEt)3]2

?' -ZYPn

Phs-^ Y'\ // ,Sph N-Bn ll

-

rHF 25"-^

PhS-(,./

.N-An

\--l

72Yo

Ph 73o/o

c RCH(SPh)CH:CHSPhI become liiJ(l $ith Cp2Ti[P(OEt)1],and Mg. hc' kctones.2Conjugated dienes and

-.-

rTakeda, T., Nozaki,N., Saeki,N., Fujiwara,T' TL 40' 5353(1999). 2Takeda, T., Taguchi,H., Fujiwara,T. TL 41,65 (2O0O). 3Takeda, T., Takagi,Y., Saeki,N., Fujiwara,T. TL 41,837'7(2O0O). 4Rahim,M.A., Fujiwara,T., Takeda,T. 5L1029(1999). sRahim,M.A., Fujiwara,T., Takeda,T. T 56,'163(2000). 6Fujiwara,T., Kato,Y.,Takeda,T. H 52,147(2000).

Titanocene dicarbonyl. 19, 347-348; 20, 384 Intramolecular ene reaction.t Enynes and dienynes undergo this cycloisomerization in the presenceof Cp2Ti(CO),

'*T)

-

.

\"'K

\

/

-' cooEt I ::.::r.lorms alcohols to nitriles t::r ..ic' rS activator and acetone

|.:.. l: .

S TL40,7355(1999).

nnane. r.:::: Sn-Li exchange(with BuLi), t::,philes. The (trimethylsilyl)r :::ric afterward.

OH - BF".OEI, BurSnH I - o^.1-r.r.^r.r-OH cH2ct2 I R

Aromatic aldehydes bearing an o-alkenyl substituent is reduced selectively when MejAl is added.3This selectivityis a manifestof chelativeactivation. Reductive amination,a A method for the conversion of carbonyl compounds to amines is by reaction with BujSnH and ammonium salts (derived from pnmary or secondaryamines) in DMF at room temperature. Hydrostannylation,s Regioselective hydrostannylation of several types of alkynes (to yield mainly ct-stannyl derivatives) is catalyzed by a molybdenum complex. rKamimura, K., Wada,M. TL 40,9059(1999). 2ooi,T.,Uraguchi, D., Morikawa,J.,Maruoka,K. OL2,2015(2000). rAsao,N., Shimada, T.,Yamamoto, Y. TL 41,9533(2000). aSuwa, T., Sugiyama, 8., Shibata, I., Baba,A. SL 556(2000). 5Kazmaier, U.,Schauss, D.,Pohlmann, M. OLl,l0l7 (1999).

Tributyltin hydrid*2,2' -azobis(isobutyronitrile). 19,353-357 ; 20, 391-394 D efunctionalizations. Heteroarenesulfonyl groups are reductively severed without affecting a geminal c-F bond.r A clean deoxygenation of alcohols via reduction of the corresponding thionocarbonatescalls for binding the tin hydride to a polymer and using trimethoxysilane to recycle the spent reagent.2 A method for synthesis of chiral cyclohexene derivatives from 4-substituted cyclohexyl halides involves derivatization to the Grignard reagent, reaction with menthyl (S)-2-bromophenylsulfinate, and then treatment with Bu:SnH, AIBN, and methylaluminum diphenoxide with irradiation by a sun lamp.3

n

Tributyltin hydride-2,2' -azobis(isobutyronitrile)

Amidoyl radicals uue generated from electron-richalkenesuch as enol deriraure.

""n\,\ \.',\*

fl? g^,*^."pn Group-transfer reactinns. A.Si- or P-linked aryl group separatedby five bonds to a carbon radical has the tendency to migrate to the carbon center.This reaction pattern can be exploited in a synthesisof 2-hydroxyalkylbiaryls from 2-bromobenzyl alcohols.a'5

R I

(Yo'\,

O ll- nr

Reductive cyclization, The Bu,Sn ensuingcarbonradicalsare liableto crch system.rr

[f\ao' %Ar

KF / H:O

A"lsi

BnOOC-N

\r This process is also applicable to arylation of secondaryaliphatic radicals,6and a carbon radical generated from O-S bond homolysis followed by radical transfer can be trapped.T

ar-l

OH

I I

w-'/

Cyclizations. Bromoarenes form radc cyclization routes to aporphines-indoldll

Ph

-\,.\ l

o-SAr

N-OBn

alkaloids.rl

Bu3SnH- AIBN/ PhH ;

,"\a"\

)-oe

R Bu3SnH- AIBN

%e,.

ph " P h- ^ r ' M"rsi'"''o I

oR

*

MeO

M&-y',

70o/o h eussnft-nlen

o

PhH

tl

'

o

----.t:-\ t / | l( |

fi-A.^on

L-J

MeO R

Bu3SnH- AIBN + PhMe r

I

MeO'\

*-./ R-\

R

R R 1,2-Migration of an acyl group to a nitrogen radical generatedfrom a-azido-B-keto estersto form amides(lactams)dis a pathway not observedin ionic reactions.

MeO MeO

t

I

r

A

r-"

MreoolNs

Bu3SnH- AIBN PhH

Bu3snH - AIBN PhMe

l

['/l€O\

rrc'

A

MeOOC 70To

MeO

R

Tritnvltiriydride-f2'-rtoDHisotrqmilrl"t

Ll

A m i d o y l r a d i c a | S a r e g e n e r a t e d f r o m a m i d o y l s e lqe n i d e s . I n t h e p r e s e n c e o f a n

electron-rich alkene such as enol derivative, addition occurs 3':S.H - AIBN + r,teAJl0Ph )2 \-

fl8

nv PhH

r. -' jl .eparatedbY five bondsto a e:-. - jnt!'r. This reaction pattern can 5 alcohols.a .'.hromobenzyl I :'

q^,*ot"pn

*

oR Aoa

o o o R ll il l

Bu3SnH- AIBN PhH A

ruVon

o

Reductivecyclization.TheBulSnradicaladdstoo.alkylaldoximesandthe groupr0 or conjugated ensuing carbon radicals are liable to cyclization with a carbonyl system.ll

K

I \'/-oH ...^Ar

t.

Bu3SnH-AIBN

BnOOC-N

\r

a#

PhH

\2,,

u 'NHBn

N-OBn 56lo

.1n aliphaticradicals,6and a car* cd by radical transfer can be

a. 1.

in synthesis,including cyclizations. Bromoarenesform radicals that can be exploited protoberberine-pavine and cyclization routes to aporphines-indolo[2,1-a]isoquinolines'r2 alkaloids.rl Ph

lr

\,\ -

MeO

MeO

0o/o Bu3SnH- AIBN

MeO :

I

- - .

PhMe A

R

MeO MeO R

i

MeO

R

K

T , il' l=3"" -.,1 eeneratedfrom ct-azido-p-keto rt'. ..'.1in ionic reactions. f:

*"oY)a\ ".o'YY

,a-\_ /-NH

ooc

70o/o

ftr Meo,\< OMe

""o6('l.fo Bu3snH.A,BN ^ PhN''!e veo'V\--l%orrre R=Me,cooR-620/o

Tributyltin hydride-2,2'-azobis(isobutyronitrile)

Ring closure is expected for a radical precursor set with an unsaturation four bonds away when such a compound is treated with BujSnH-AIBN. The versatility of such cyclizations is derived from allowance of many varieties of substitution patterns and heteroatomsbetween the reactive centers. Furthermore, as shown in a synthesisof 2,4-disubstitutedpyrrolidines,radiastereoselectivitymay be controlled in

Bu3SnH AIBN / PhH I

(

certain cases.

Phse) Ph._,\N,

Bu3snH-ArBN ai' rnr/*) ;;;*

a

R

. rnr/*)J

R

R

R=H 38 R = P(O)Phz 1

a,-.'\--

1

24

Bu:*

SiMe2Ph _\_ -SiMes

AlBri + r

"y-sultams,16 Basedon this method,expedientaccessto conjugatedexocyclic dienes,15 indoles.lTand ct-oximino-ry-lactonesr8 has beendevised. Also notable is the formation of a h 7,7-diyne.22 OH

/--\

pcPh3

fB,

( X . N -o_(

- AIBN Bu3SnH PhMe A

efi"

n

A

80%

The regioselectivity of cyclization through bond formation at either the ct- or r' B-position of a pyrrole dependson the electronic nature of the N-substituent.

ueo'y'-yt' l l V*Ao

R ,,N'.

A process involving cyclization-fra3l clopropanes23is a radical alternative to d 2-aminocyclooctenenitrile is formed in 56(

RN-1

Meolz\rA2 Bu3snH-ArBN \--l l + l l l l + Phi/e a \,A1rAo

Meo

NC

{^

SEM

SEM R=Me R = COOMe

43% 15Yo

-' LY^

Br

n=1.2.4 32o/o

Tandem cyclization is valued for synthetic efficiency. As illustrated, approachesto the BCD-ring segment of steroids2{)and a precursor of (*)-paniculatine2r are worth mentioning.

rWnuk, S.F.,Rios, J.M., Khan, J., Hsu. \'.-L ,l( 2Boussagnet,P., Delmond, B., Dumartin. G . R sImboden,C., Villar, F., Renaud,P. Ol l. 871 r aClive,D.L.J., Kang, S. ZZ 41, 1315 (2ffir sStuder,A., Bossart,M., Vasella,T. OL 2.9t5 t

Tfibutyltin hydride-2,2,-azobis(isobutyronitrile)

r .: r\tth an unsaturationfour r 11.- \nH AIBN. The versatility : - : " . \ a r i e t i e so f s u b s t i t u t i o n

Bu35nH

: : . i . . : t h r ' r m o r ea.s S h O w ni n a ) - : , , i r i l t \ m a y b e c o n t r o l l e idn

p

J

h

/

A I B N/ P h H A

74To \

SiMe2Ph

$*, K

SiMe2Ph

'.,.-\,,,".

1 24

Bu3SnH

SiMeq +

AIBN/ PhH A

d - ' . r e l r c d i e n e s , r1s- s u l t a m s , l 6

82o

(+)_paniculatine

Also notable is the formation of a bicyclo[3.1.1]heptaneskeleton from an acyclic 1.7-divne.22 OH

,^'vN \ l o\

Bu3SnH AIBN/ PhH

80%

Pi..,

A

Br > 85a/o

lltr)n at either the cr- or . ' . \ ' - s u b s t i t u e n t .I e

A process involving cyclization-fragmentationof 2-(o-bromoalkyl)-l,l-dicyanocycfopropanes23is a radical alternative to the Thorpe-Ziegler reaction of dinitriles. Thus, 2-aminocyclooctenenitrile is formed in 56Vo yield.

s

MeO

. I

\

-

il

Br

PhH ^

lH, I

NC_Yz\

L+4"

n=1.2.4

I

t

Bu"SnH- AIBN

32Yo

\. rllustrated,approachesto - -paniculatine2l are worth

rWnuk,S.F.,Rios,J.M., Khan,J.,Hsu,y-L. JOC 65,4t6g(2OOO). 2Boussagnet, P, Delmond,B., Dumartin,G.,pereyre, M.TL41,3377(ZOOO). 3lmboden, p. OL l,873 (1999). C.,Mllar,F.,Renaud, 4clive,D.L.J.,Kang,S. TL4t, l3t5 exn). sStuder, A., Bossart, M., Vasella, T. OL2,gg5 eOO}).

Tticarbonyl(pentamethylcyclopentadienyl)rhenium

oAmrein,S., Bossan,M., Vasella,T., Studer,A. JOC 65,4281 (2000). TPetrovic,G., Cekovic, Z. OL2,3'/69 '2OOU. sBenati,L., Nanni, D., Sangiorgi,C., Spagnolo,P.JOC 9,7836 (1999). 'Keck, G.8., Grier, M.C. SL 165'1(1999'). roNaito, T., Nakagawa, K., Nakamura, T., Kasei, A., Ninomiya, I., Kiguchi, T. JOC 64,2003 (Iggg). lrNaito, T., Fukumoto,D., Takebayashi,K., Kiguchi, T. H 51,489 (1999). r2Orito,K., Uchiito, S., Satoh,Y, Tatsuzawa,T., Harada,R., Tokuda,M. OL2,307 (2000). r3Orito,K., Satoh,Y, Nishizawa,H., Harada,R., Tokuda, M. OL2,2535 eO}U. raBesev,M., Engman,L. OL 2, 1589 (2000). r5Sha,C.-K., Zhan,Z.-P.,Wang, F.-S. OL2,20ll (2000). r6leit, S.M., Paquette,L.A. IOC 64,9225 (1999). rTTokuyama,H., Yamashita,T., Reding, M.T., Kaburagi, Y., Fukuyama, T. JACS l2l,37gl (Iggg). r8Clive,D.L.J., Subedi,R. CC 231 Q000\. leEscolano,C., Jones,K. TL 41,8951 (2000). 2oTomida,S., Doi, T., Takahashi,T. TL 40,2363 (1999). 2rSha,C.-K., Lee, F.-K., Chang,C.-J.JACS 121,9875 (1999). 2zBogen,S., Fensterbank,L., Malacria,M. JOC 64,819 (1999). 2rCurran,D.P..Liu. W. SL I l7 (1999).

Ttibutyltin hydride-triethylborane.15,333;16,350;17, 363-364;18,372; 20, 394 Cyclization,t Addition of BujSnH to B-allenyl-O-benzoyl oximes also causes cyclization.

)c"1

.

Bu3SnH- Et3B

\-N

SnBu"

\/Y

,n ,l\

|

!n P(

be'

t't">1, BulsnH-ArBN

'-;;;;*

+A Ph'

82Yo Radical additian.

rChen,H., Hartwig,J.F.ACIEE3t. -r,r9 Trichloroacetonitrile.

Hydroxyl protection.t Alcol reaction. Three sets of conditions I using DBU in MeOH, TsOH.H;( Zn-NHaCl in refluxing ethanol. Acid chlorides.: Sensitire rr treatment with Ph3P-CI.CCN ar roc

rYu,B., Yu,H., Hui,Y.,Han.X. Sl 75-r, rJang,D.O.,Park,D.J.,Kim, J. Il $. 5 TFichloronitromethane.

Dissulfides,t Treatment of r disulfides. ,l-Nitrosothiols are rhe rrr

bst 7 1o/o

\ /:c
("

cH2ct2

H O I

\.'^-o \J/ \

o'---o 75%

Isomerization. The Baylis-Hillman adducts from aromatic aldehydes and acrylic esters undergo stereoselective isomerization to (E)-2-hydoxymethylcinnamicesters.2 Adducts derived from o-nitroaraldehydes behave differently due to intervention of an intramolecular redox reaction, leading eventually to N-oxides of 4-hydroxyquinoline-3carboxylicesters.3

Trifluoromethyl a-aminoalkyl L.rc TFAA-pyridine on N-substituteda-amino r Rearrangemenf. 2-Pynolidinemetherr expansion to give piperidin-3-ols.a Carbory less carbon by TFA-TFAA-NaNO:.

Ttifl uoroaceticanhydride,TFAA

r,: ,,\\'gen), Et,rB promotes radical o:r3'unds is effected.aRegioselective r. :::r t() a carbon radical center.s r:r .licomplishedwith RCHO.b ^'

ll

rt

F

l-1

'

"

\

+>( H

),,,OH

/

Ph 35 : 15) 44%

tf. .::. .rlkvl residueon reactionwith a g , ' . - :r r c l d s . T Ir .\ JOCU,803 (1999). x. : : ., 1999). F k,'.1 1899(2000).

Simmons-Smith reactian,4 A dramatic acceleration of the cyclopropanation by CF.TCOOHis probably due to formation of a more reactive speciesCFTCOOZnCH2I. rBouzide, A., Sauve, G.TL40,2883(1999). 2Kim,H.S.,Kim, T.Y.,Lee,K.Y.,Chung,Y.M.,Lee,H.J.,Kim, J.N.TL41,2613(2000). rKim, J.N.,Kim, T.Y, Lee,K.Y, Kim, H.S.,Kim, T.Y OL2,343 (2000). aYang,Z., Lorenz,J.C.,Shi,Y. 74 39,8621(1998).

Tiifl uoroacetic anhydride, TFAA. 18, 376-37 7 ; 19, 361; 20, 396-397 Dehydration. Endocyclic enecarbamates are prepared from the coresponding lactams via reduction and subsequentdehydration with TFAA-2,6-lutidine.l Regiochemically divergent lactonization processes of a hydroxynaphthoquinone derivativeinducedby TFAA and MerSiOTf are observed.2

)

cF3cooH

tL

I lt. .r75-376;20' 395-396 rr,,\ure to CF.TCOOH effectsthe ' .c. whileretaining the Primary

k'

OPMB

^ :

'v

l

,

/^o

--1 7 5o/o

:: rromatic aldehYdesand acrylic . i -hrdoxymethylcinnamic esters'2 i of an intervention to due :jrcntly -,,rides \ 4-hydroxyquinoline-3of t,'

a-aminoalkyl ketones,l The Dakin-West reaction using Trifluoromethyl TFAA-pyridine on N-substitutedd-amino acids affords the fluorinated ketones. Rearrangemenf. 2-Pyrrolidinemethanol derivatives undergo stereoselective ring expansionto give piperidin-3-ols.aCarboxylic acids are convertedto nitriless with one less carbon by TFA-TFAA-NaNO2.

Tiifluoromethanesulfonic acid (triflic acid)

Tr-rrr

Nitrodeboration.. lpso-substitution of arylboronic acids to give nitroarenes is accomplishedwith TFAA and NHaNOj. Reductive functionalization of (arylseleninyl)acetates.T when the pummerertype rearrangementof PhSe(o)CH2cooR is carried out in the presenceof a reactive silane (e.g.,

Dealkylation,5 Protodemethylation r! r ethyl group in the following reaction seqrrd

allylsilanes,MeqSiNs)carbon chain homologationor functionalizationof the estersresults. rOliveira,D.F.,Miranda,P.C.M.L., Correia,C.R.D.JOC 64,6646Oggg). 2Qabaja, G.,Perchellet, 8.M.,Perchellet, I.-P.TL4l, 3007(2000). 3Kawase, M., Hirabayashi, M., Kumakura, H., Saito,S.,Yamamoto, K. CpB 48,I l4 (2000). aCossy, J.,Dumas,C.,Pardo,D.G.EJOC 1693(l9gg). sSmushkevich, Y.I., Smushkevich, V.Y, Usorov,M.I. "/CR(S/tj2'l (lggg). 6Salzbrunn, S.,Simon,J.,Prakash, G.K.S.,Petasis, N.A.,Olah,G.A.Sa 14g5(2000). TShimada, y.ZZ 41,4637(2OOO). K., Kikuta,Y.,Koganebuchi, H., Yonezawa, F.,Aoyagi,S.,Takikawa, N-(T[ifl uoroacetyl)succinimide. Trifluoroacetylation.t Alcohols, phenols, and amines are acylated by the title reagent(14 examples,83-997a). rKatritzky, A.R.,Jang,B., Qiu,G., Zhang,Z.S 55 (1999). 21212-Triflioroethyl

carbamates. ureas,t The carbamates RNHCooCH2cFs are obtained by an electrochemical reaction of primary amides (RCoNHr) in cFjcH2oH. They undergo aminolysis to afford unsymmetrical ureas. rMatsumura, Y, Satoh,Y.,Onomura, O.,Maki.T. JOC 65.1549(2000). Tlifluoromethanesulfonic acid (triflic acid). 14, 323-324;15,339; 18,377;19, 362-363:20,398-399 Allylation.t Triflic acid is capableof catalyzingthe reactionof allyltributylstannane with aldehydes(not ketones) in water. Michael reaction.2 For conducting a Michael reaction of g-ketoesters with conjugated esters and ketones at room temperature under solvent-free conditions, triflic acid is useful. cyclizations. A stereocontrolled synthesis of trisubstituted tetrahydropyrans by condensationof homoallylic alcohols with aldehydesis developed.3Treatmentof rHp ethers derived from unsaturatedalcohols with triflic acid leads to oxygen heterocycles.a

CI".L,-O

cF:So:H'r"tb 65To

rhazinilam

I Loh, T.-p., Xu, J. TL 40, 2431 (1999). 2Kotsuki, H., Arimura, K., Ohishi, T., Maruzasr RrCloninger,M.J., Oveman,L.E. JACS l2l. l09l , I aDixon, D.J., Ley, S.V.,Tate,E.W ./CS(P/r 183 , I 5Johnson,J.A., Sames,D. JACS 122,6321 (?Vnl

T[ifl uoromethanesulfonic

anhydride

t triffc

15, 339-340; 16, 357-358; 18, 377 -37 8 : l).'. Nitrile oxide generation.t O-Silllaod precursors of nitrile oxides, by virnr of Tf2o-EtjN.

1,3,4-Oxadiazoles.2 Tf2O-pyridine rs : diacylhydrazines.

'Muri, D., Bode,J.W.,Carreira, E.M.OL 2. 5-t9r! 2Liras,S.,Allen,M.P.,Segelstein, B.E..tCgl. r_r: ,

Tfifluoromethanesulfonic anhydride (triflic anhydride)

.rcids to give nitroarenes rs

).:. tue\.

Dealkylation.s Protodemethylation is the key to functionalization of an unactivated ethyl group in the following reactionsequence.

When the Pummerer-type

r. :r-c.\enceof a reactive silane (e.g., c:..,r.rlizationof the estersresults. !-:'

COOMe

1999).

l l

r:

K. CPB48.I 14(2000). cFlso3H

-_- re99). : h (. \.t1.1485(2000). S .

cH2ct2

Irliikawa,Y.TL41,4637QUn).

cFlcH'oH

a:r'.::',d\are acylated by the title

70"

I

I

I V

COOMe N

I ^r.irned by an electrochemical 1'. . undergoaminolysisto afford

.t.

_ rx)t.

. : : r 1 5 ,- 3 3 91;8 , 3 7 7 ; 1 9 , hr :J.icrionof allyltributylstannane :, --'.retion of B-ketoesterswith t"r-: ., )lvent-freeconditions,triflic

by u:...^.riruredtetrahydropyrans :. .:-'\!'loped.r Treatment of THP tr . .,.i.t()oxygenheterocycles.a

I Loh, T.-P., Xu, J. TL 40, 2431 (1999\. 2Kotsuki, H., Arimura, K., Ohishi, T., Maruzasa, R. JOC 64,37'10 (1999). 3Cloninger,M.J., Oveman,L.E. JACS l2l,lO92 (1999). aDixon, D.J., Ley, S.V.,Tate,E.W. JCS(PI) 1829 (2000). 5Johnson,J.A., Sames,D. JACS 122,6321 (2OOO).

Tiifluoromethanesulfonic

anhydride

(triflic

anhydride).

13, 324-325;14,324-326;

15, 339-3 40; 16,357-3 58; 18,371-37 8; 19, 363-365; 20, 399 Nitrile oxide generation.t O-Silylatedhydroxamicacids are identifiedas stable precursorsof nitrile oxides, by virtue of their susceptibilityto transformationby Tf2O-EtrN. 7,3,4-Oxadiazoles.2 Tf2O-pyridineis a mild reagentfor the cyclodehydration of diacylhydrazines. tMwi, D.,Bode,1.W.,Canetra, E.M.OLZ,i3g (2N0. 2Liras, 5., Allen,M.P.,Segelstein, B.E.SC30,437(2N|D.

(Tiifl uommethyl)trimet}ylsilane

Tlifluoromethanesulfonyl azide. Diazocarbonyl compounds.l The title reagent is particularly useful for the introduction of an ct-diazo group to cr-nitro carbonyl compounds.

IBlazejewski,J.-C.,Anselmi,8.. \'\'ilmshun rlshizaki,M., Hoshino,O. Z56. g8l-rrl[fJrr

rCharette, A.B., Wurz,R.P, Ollevier,T. JOC 65,9252(2O0O).

Tii-2-furanylgermanFtriethl'lborer Organotrul Defunctianalimtion.t with this reagentvia radical intermedrrc

3-(Tiifluoromethanesulfonyloxy)-3-trifluoromethylpropeniminium triflate. 2-Trifluoromethylquinolines.r Reagent 1 transforms arylamines into 2-trifluoromethylquinolines in one step.

G"',.

Me2N

rfo83% (1)

I Baraznenok, I.L., Nenajdenko, V.G.,Balenkov a, E.S.EJOC937(1999).

; )

I Ia

t 7

a"

if NaBH4is usedin conjunction. rNakamura. H., Shino\utr..ll T..Yorimitsu,

Tiiisobutylaluminum. 19, 367--16.q Reductive rearrangement Errcr enol ethers establishes a horrxrk ATCHTOC(=:CH2)Meto ArCH:CH :CH Carbocyclesare formed on subjecuq

Claisen realrangementfollowed br rod one step.3

2-(TFifluoromethanesulfonyloxy)vinyl aryliodonium trifl ates. Aryliodonium salts.t Unsymmetrical diaryliodonium triflates and aryl(a1kyny1)iodonium triflates are readily synthesizedfrom the title compounds by reaction with ArLi and alkynyllithium reagents,respectively.Ethylene is one ofthe byproducts. +

Ar-l-A/ Ar-l Tfo

i_

Tfo-

OTs

-a Ar-l:R Tfo-

rPirguliyev, N.Sh.,Brel,VK., Akhmedov, N.G.,Zefirov,N.S.S 81 (2000). S-TFifluoromethyldiarylsulfonium trifl ates. Trifluoromethylation. These reagents are prepared from ArS(O)CF.,. They donate the trifluoromethyl group to suitable nucleophiles (e.g., arenes).

rdu Roizel, B., Sollogoub,M., Pearce..{J - i rSollogoub,M., Mallet, J.-M., Sina1.P .{Clt 'Wang, W, Sollogoub,M., Sinay.P. ACIEE

rYang,J.-J.,Kirchmeier, R.L.,Shreeve, J.M.JOC 63,2656(1998).

(Tiifl uoromethyl)trimethylsilane. I 5, 34 | ; 18, 378-37 9 ; 19, 366-367 ; 20, 400 Trifluoromethylation. Imines show similar reactivity as carbonyl compounds in accepting the MejSi and CF3 groups from MesSiCFj.r In the presenceof CsF of KF, the title reagentconverts l-alkynes to alkynyltrimethylsilanes.2

I -Ttiisopropylsiloxy- 1,2-propadicc Acrylic acid a-anian equivalcat the title compound with t-Buli rn Tl alkylated.Quenchingwith aldeh!desg

--15-, rStergiades, I.A.,Tius,M.A. JOC61.

1-T[iisopropylsiloxy-1,2-propadiene 451

:. particularly useful for the lr':la()Unds. ni

) lpnrpeniminium triflate. s: ::r\ arylamines into 2-trifluoro-

lBlazejewski, J.-C., Anselmi, E., Wilmshurst, M.P. TL 40, 5475 (1999). 2 l s h i z a k iM , . , H o s h i n o ,O . 2 5 6 , 8 8 1 3 ( 2 0 0 0 ) .

Tii-2-furanylgermanFtriethylborane. Defunctionalizatian.t Organobromides,iodides, and xanthatesare defunctionalized with this reagentvia radical intermediates.Only catalytic amount of the germaneis required if NaBH4is usedin conjunction. rNakamura, T.,Yorimitsu, H., Shinokubo, H., Oshima,K. SZ 1415(1999). Ttiisobutylaluminum. 19, 361-3 68 Reductive reanangemenf. Extension of the previously discovered reaction to enol ethers establishes a homologation route for alcohols, for examples., ATCH2OC(:CH2)Me to ATCH2CH2CH(OH )Me.I Carbocyclesare formed on subjectingunsaturatedS-, Se-, and C-glycosidesto r-Bu.1Al.2 Claisen rearrangementfollowed by reduction of the resulting ketones is accomplishedin

'_:-

.999).

one step.3

n triflates, triflatesand ary1(alkynyl)I::-:r le . npounds by reaction with ArLi r':: ,l the byproducts.

r

o-OH 57% + p_OH38%

:'-l:-A/ Tfoi-Bu3Al

Ar-l----E-R

BnO

).

OBn

96%

:000).

- i:i:lL'\

l

eno"')-ion

Tfo-

r.J rr()m ArS(O)CFj. They donate

._^\ t

rduRoizel,8., Sollogoub, M., Pearce, A.J.,Sinay,P CC 1507(2000). 2Sollogoub, M., Mallet,J.-M.,Sinay,P.ACIEE39,362(2000). rWang,W, Sollogoub,M., Sinay,P.ACIEE39,2466(2N0).

lw.

l-" 19.366-367;20,400 r1:.:l\ as carbonylcompounds in : I: rh!'presence of CsFof KF, the aa-

1-TFiisopropylsiloxy- 1,2-propadiene. Acrylic acid a-anion equivalent.t O + C Silyl migration occurs on treatment of the title compound with t-Bul-i in THF at -78'. The ensuing lithium enolate can be alkylated. Quenching with aldehydesgeneratesBaylis-Hillman adducts. rStergiades, I.A.,Tius,M.A. JOC 64,7457(1999).

Thimethylaluminun

T[iisopropylsilyl triflate. 20, 4Ol This reagent is a valuable component of [4 + 3] 2-(Triisopropylsi.lory)acroleinl by prepared from 2-methoxy-2-methyl-1,3-dioxan-5-one It is conveniently cycloadditions.

Diels-Alder reaction.u The Drelr-A stereoselectiveon using Me,Al to tether h each of which contains an allylic hydrorr 5

reaction with i-Pr:SiOTf-Et3N.

rKurosu.M. TL 41,591(2000). rAbe.N., Hanawa, \t \ H., Maruoka,K.. Sasalit. rSchneider. J.TL 4l' j04-1(lffrl C..Brauner, aBertozzi, F.,Olsson,R.,Frejd,T. OL 2. I lti '-lI

o

A

i-Pr3Si-/.\ i-Pr3SiOTf- Et3N

x;"

i

r'Yo

*;-

H

Silyl carbamates.2 Primary and secondary amines are protected as triisopropoxycarbonyl derivatives on consecutivetreatrnentwith carbon dioxide (EtrN--CH2Cl2,-78') and i-PqSiOTf. The silyl carbamatesare decomposedby BuaNF at ice temperature.

Ttimethyl orthoformate. Methyl 7,7-dimethoxyalkanmtcsHC(OMe)3-MeOH in the presenceof T