Highly Diastereo- and Enantioselective Rh-Catalyzed Hydrogenation of Tetrasubstituted Dehydroamino Acid Esters: Access to Chiral α-Amino Acid Derivatives

Rh-(R,S_P)-JosiPhos complex-catalyzed highly enantioselective hydrogenation of tetrasubstituted dehydroamino acid esters has been achieved, furnishing the chiral β-cyclic and β-branched α-amino acid esters in high yields (92-98%) with high diastereo- and enantioselectivities (>99:1 dr, up to 99% ee). This method provided an efficient strategy to nonsymmetrically chiral β-cyclic and β-branched α-amino acid esters under mild conditions.