Catalytic, Asymmetric Mannich-Type Reactions of α-Imino Esters Bearing Readily Removable Substituents on Nitrogen

Abstract
Catalytic, enantioselective Mannich-type reactions of α-imino esters bearing readily removable substituents on nitrogen are described. Several N-carbamate-protected α-imino esters, which are readily prepared from 2-bromoglycine esters using a polymer-supported amine, reacted with silicon enolates to afford the desired adducts in high yields with high enantioselectivity using a copper(II)−diamine complex. Easy deprotection of the product amine and transformation to free α-amino acid derivatives have also been demonstrated.
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