New Method for Preparation of erythro-β-Hydroxyamino Acids using Catalytic Asymmetric Hydrogenation

Abstract

Catalytic asymmetric hydrogenation is one of the most efficient and useful methods to obtain a variety of chiral products with high optical purity. Generally, the asymmetric hydrogenation through dynamic kinetic resolution developed by Noyori et al can be utilized for chirally labile linear α-amino β-keto esters to afford syn β-hydroxyamino acids with high diastereo- and enantioselectivities. However it is difficult to directly obtain anti (erythro) β-hydroxy amino acids using their protocol. We report here direct anti selective hydrogenation of α-amino β-keto ester derivatives with high stereoselectivities via dynamic kinetic resolution using chiral RuCl₂(binap) catalyst.