catalyze the enantioselective aldol reaction of aldehydes with ketene silyl acetals in DMF at roomtemperature. The platinum(II) complex-catalyzed the enantioselective aldol reaction of aldehydes with 1-methoxy-2-methyl-(1-trimethylsilyloxy)propene gave the corresponding aldols in high yields with enantioselectivity up to 92%. With 5 mol % loading of the complexes, the enantioselective aldol reaction of aldehydes
Reaction of silylketene acetals with acryloyl and mono substituted acryloyl chlorides.
作者:Gérard Rousseau、Luis Blanco
DOI:10.1016/s0040-4039(00)98988-3
日期:1985.1
The reaction of silylketene acetals with acryloyl, methacryloyl and crotonyl chlorides gave, after addition of methanol, mainly substituted glutaric esters, probably via a (2 + 2) cycloaddition.
In the presence of 20 mol% of a chiral (acyloxy)borane (CAB) complex prepared from BH3·THF and a chiral mono-O-acylated tartaric acid, achiral silyl enol ethers or ketenesilylacetals react with achiral aldehydes to afford the corresponding aldol-type adducts in good yields with high enantio- and diastereoselectivities. Furthermore, the reactivity of aldol-type reactions can be improved without reducing
Highly selective, kinetically controlled enolate formation using lithium dialkylamides in the presence of trimethylchlorosilane
作者:E.J. Corey、Andrew W. Gross
DOI:10.1016/s0040-4039(00)99920-9
日期:1984.1
The deprotonation of ketones and esters with lithium dialkylamides in the presence of trimethylchlorosilane leads to enhanced selectivity for the kinetically generated enolate. Lithium -octyl--butylamide is shown to be superior to lithiumdiisopropylamide in the regio-selective generation of enolates and in the stereoselective formation of enolates.