Highly Enantioselective, Catalytic Conjugate Addition of Cyanide to α,β-Unsaturated Imides

Abstract

(Salen)Al-Cl complex 1a catalyzes the asymmetric conjugate addition of hydrogen cyanide to alpha,beta-unsaturated imides in high yields and enantioselectivities. The cyanide adducts can readily be converted into a variety of useful chiral building blocks, including alpha-substituted-beta-amino acids and beta-substituted-gamma-aminobutyric acids. Mechanistic data obtained thus far point to a cooperative bimetallic mechanism for nucleophile and electrophile activation.