A N,N'-dioxide-copper(II) complex as an efficient catalyst for the enantioselective and diastereoselective Mannich-type reaction of glycine Schiff bases with aldimines.

Mild mannered! A highly diastereo- and enantioselective Mannich-type reaction of glycine Schiff base 1 has been developed by using the N,N'-dioxide L-Cu(II) complex as a catalyst. Various optically active anti-alpha,beta-diamino acid esters were obtained in good yields with up to 96:4 d.r. and 97% ee. This straightforward method features a low catalyst loading and mild reaction conditions.