Diastereo- and enantioselective hydrogenation of α-amino-β-keto ester hydrochlorides catalyzed by an iridium complex with MeO-BIPHEP and NaBArF: catalytic cycle and five-membered chelation mechanism of asymmetric hydrogenation.

The development of Ir-catalyzed asymmetric hydrogenation of α-amino-β-keto ester hydrochlorides is described. This reaction proceeds through a dynamic kinetic resolution to produce anti-β-hydroxy-α-amino acid esters in a high diastereo- and enantioselective manner. Mechanistic studies have revealed that this unique asymmetric hydrogenation proceeds through reduction of the ketone moiety via the five-membered transition state involving the chelation between the oxygen of the ketone and the nitrogen of the amine function.

Catalytic asymmetric hydrogenation of alpha-amino-beta-keto ester hydrochlorides using homogeneous chiral nickel-bisphosphine complexes through DKR.

Homogeneous chiral nickel-bisphosphine complexes catalyze the asymmetric hydrogenation of alpha-amino-beta-keto ester hydrochlorides through dynamic kinetic resolution to efficiently afford anti-beta-hydroxy-alpha-amino esters with high diastereo- and enantioselectivities.