Chlorotrimethylsilane promoted asymmetric Michael reaction of chiral enamines of α-alkyl β-keto esters

By the promotion of chlorotrimethylsilane, asymmetric Michael reaction of the chiral enamines (2) of α-alkyl β-keto esters (1) with methyl vinyl ketone and ethyl acrylate proceeded to afford, after hydrolysis, either enantiomer of the corresponding adducts (4) in a good enantioselectivity.