Reactions of Tin(IV) Enolates Obtained from <i>O</i>-Stannyl Ketyls under Neutral Free Radical Conditions
作者:Eric J. Enholm、Paul E. Whitley、Yongping Xie
DOI:10.1021/jo960639e
日期:1996.1.1
Under mild and neutral free radical conditions, an alpha,beta-unsaturated ketone reacted with tributyltin hydride to produce an intermediate resonance-stabilized allylic O-stannyl ketyl. Upon subsequent hydrogen atom abstraction, a tin(IV) enolate was afforded which could be quenched with a variety of electrophiles and form new carbon-carbon bonds. Aldehydes react to produce aldol-type products and both intramolecular and intermolecular carbonyl addition reactions were investigated using this strategy. Using similar methodology, the tin(TV) enolate could be quenched in the presence of HMPA with various alkyl halides and alpha,beta-unsaturated carbonyl compounds (Michael accepters) to yield alkylated products in good yields. These reactions represent a very mild regioselective alternative to metal enolate formation which usually requires strong bases such as LDA or strongly reductive dissolving metal conditions to achieve success. New carbon skeletons for natural product synthesis can be readily constructed using this chemically neutral approach.
Aldol reactions with a .alpha.-trimethylsilyl ketones. Dual roles of the trimethylsilyl group for regiospecific generation of enolate equivalents
作者:Tan Inoue、Toshio Sato、Isao Kuwajima
DOI:10.1021/jo00198a017
日期:1984.11
Dual roles of trimethylsilyl group for specific generation of enolates from β-ketoalkyltrimethylsilanes. Regiospecific preparation of two types of acyclic aldols
作者:Isao Kuwajima、Tan Inoue、Toshio Sato
DOI:10.1016/s0040-4039(01)85762-2
日期:1978.1
INOUE, TAN;SATO, TOSHIO;KUWAJIMA, ISAO, J. ORG. CHEM., 1984, 49, N 24, 4671-4674