Asymmetric additions of thioglycolates and N-Boc aldimines catalyzed by a bifunctional tertiary-amine squaramide.

A highly enantioselective asymmetric addition reaction of thioglycolates and N-Boc aldimines was promoted by a bifunctional tertiary-amine squaramide catalyst. As a result, a number of chiral N,S-acetal derivatives were efficiently synthesized with good enantioselectivities.