Stereoselective Lewis Base-Catalyzed Asymmetric Hydrosilylation of α-Acetamido-β-enamino Esters: Straightforward Approach for the Construction of α,β-Diamino Acid Derivatives

The Lewis base-organocatalyzed asymmetric hydrosilylation of alpha-acetamido-beta-enamino esters was investigated. Among various chiral Lewis base catalysts, a novel catalyst derived from L-serine was found to be the most efficient one which can promote the reaction to afford a series of alpha,beta-diamino acid derivatives with high yields (up to 99%), excellent enantioselectivities (up to 98% ee) and moderate diastereoselectivities (up to 80: 20 dr). The absolute configuration of one of the products was determined by the X-ray crystallographic analysis. In addition, the mechanism and the transition state of the reaction were proposed.