Enantioselective Synthesis of α-Hydroxy and α-Amino Phosphonates via Catalytic Asymmetric Hydrogenation

Cationic rhodium catalysts of the C 2 symmetric DuPHOS ( 1 ) and BPE ( 2 ) ligands have demonstrated the ability to asymmetrically hydrogenate a novel series of enol phosphonates ( 3 ) in good to excellent enantiomeric excess under mild conditions. Initial studies toward the catalytic asymmetric hydrogenation of enamido phosphonates ( 6 and 7 ) using the DuPHOS−Rh + catalysts are also reported.