ASYMMETRIC SYNTHESIS OF PYROGLUTAMIC ACIDS via Ni(II) COMPLEX METHODOLOGY

Abstract

Michael addition reactions between nucleophilic glycine equivalents and α,β-unsaturated carboxylic acid derivatives represent the most methodologically concise and generalized approach to the family of sterically constrained heterocyclic amino acids. Such amino acids are of critical importance in the de novo peptide design and for elucidation of peptide/protein three-dimensional structure and its biological function/activity. This review summarizes key aspects of Michael addition reactions using Ni(II)-templated Schiff bases of glycine in various asymmetric versions placing chiral auxiliary on either Michael donor or acceptor or both.