Synthesis of alpha,beta-diamino acid derivatives via asymmetric Mannich reactions of glycine imino esters catalyzed by a chiral phosphoramidite silver complex

摘要

AgOTf phosphoramidite complexes efficiently catalyze the enantioselective Mannich-type reaction between benzophenone-imine glycine methyl ester and N-tosyl aldimines in the absence of a base. The corresponding syn-adducts, which are the direct precursors of alpha,beta-diamino acids, are obtained with moderate to good syn-diastereoselectivities (up to 9:1) and high enantioselectivities (up to 99% ee). (C) 2014 Elsevier Ltd. All rights reserved.