One-pot construction of multiple contiguous chiral centers using Michael addition of chiral amine.

Multiple contiguous chiral centers were constructed in one pot using three types of multistep reactions initiated with the Michael addition of N-benzyl-2(R)-methoxy-(+)-10-bornylamide to alpha,beta-unsaturated esters, i.e., asymmetric Michael-aldol reaction, double Michael addition, and double Michael-aldol reaction. The chiral 2-methoxy-10-bornyl group as well as the benzyl group on the amino group of the products in the Michael-aldol reaction could be easily cleaved by treatment with NIS (4 equiv), and beta-amino esters with multiple contiguous chiral centers were obtained in good yield. As an application, the beta-amino-beta'-hydroxy ester obtained in the asymmetric Michael-aldol reaction was converted to the beta-lactam derivative in good yield.