Diastereoselectivity in the preparation of β-silylesters from αβ-unsaturated esters and amides attached to chiral auxiliaries

Abstract

The conjugate addition of the phenyldimethylsilyl-cuprate reagent to cinnamate and crotonate esters and amides of various known chiral auxilaries is diastereoselective, making available β-silylesters of high enantiomeric excess; the sense of the diastereoselectivity is anomalously different from established precedent in the case of silyl-cuprate addition to the cinnamate ester (1, R = Ph, R*=d).