Conjugate addition of O-silylatedketeneacetals to α,β-unsaturated carbonyl compounds in acetonitrile gave quantitative yields of the corresponding β-(alkoxycarbonyl)methyl O-silyl enolates . Site specific electrophilic substitutions of yielded the corresponding α-substituted β-(alkoxycarbonyl)-methylalkanones , , and .
Clay Montmorillonite: An Efficient, Heterogeneous Catalyst for Michael Reactions of Silyl Ketene Acetals and Silyl Enol Ethers with α,β-Unsaturated Carbonyl Compounds
作者:Motomitsu Kawai、Makoto Onaka、Yusuke Izumi
DOI:10.1246/bcsj.61.2157
日期:1988.6
The Michael addition of silyl ketene acetals to α,β-unsaturated esters (enoates) is investigated. The reaction is catalyzed by clay montmorillonite (solid acid) most effectively among various, homo...
Carbon-carbon bond formation catalyzed by lithium perchlorate in dichloromethane
作者:Manfred T. Reetz、David N.A. Fox
DOI:10.1016/s0040-4039(00)77505-8
日期:1993.2
perchlorate suspended in dichloromethane provides a mild and effective medium for Mukaiyama aldol reactions of aldehydes with silyl keteneacetal (1). 2-Cyclohexenone undergoes clean 1,4-addition under similar conditions. Catalyst activity is much higher in dichloromethane than in diethylether.
Lithium perchlorate catalyzed conjugate addition of o-silylated ketene acetals to hindered α,β-unsaturated carbonyl compounds at atmospheric pressure
作者:Paul A. Grieco、R.J. Cooke、Kenneth J. Henry、James M. VanderRoest
DOI:10.1016/s0040-4039(00)92276-7
日期:1991.1
O-Silylated ketene acetals undergo 1,4 conjugate addition to hindered α,β-unsaturated carbonyl systems at atmospheric pressure in the presence of lithium perchlorate.
Lithium Cobalt-Bis-Dicarbollide: A Novel Lewis Acid Catalyst for the Conjugate Addition of Silyl Ketene Acetals to Hindered .alpha.,.beta.-Unsaturated Carbonyl Compounds
作者:William J. DuBay、Paul A. Grieco、Lee J. Todd
DOI:10.1021/jo00102a009
日期:1994.11
The novel Lewis acid, lithium cobalt-bis-dicarbollide (1), in which the lithium ion is weakly coordinated to the Co(B9C2H11)(2)(1-)anion, is an effective, soluble catalyst for Mukaiyama-Michael reactions.