Enantioselective Conjugate Addition of Silylketene Acetals to β-Enamidomalonates. Synthesis of β-Amino Acid Derivatives

Abstract

[reaction: see text] Conjugate addition of silylketene acetals or enolsilanes to enamidomalonates proceeds with excellent chemical efficiency and good selectivity using Cu(OTf)2 and a chiral bisoxazoline. The effect of the Lewis acid, ligand, the N-acyl substituent, and the nucleophile on yield and selectivity for the addition product have been evaluated.