Synthesis of ortho-phenyl substituted MeO-BIPHEP ligand and its application in Rh-catalyzed asymmetric hydrogenation

Abstract A new BIPHEP-type ligand with phenyl groups at the 3,3′-positions, o -Ph-MeO-BIPHEP 3 was prepared. This ligand afforded excellent enantioselectivities when used in the Rh-catalyzed asymmetric hydrogenation of α-dehydroamino acid derivatives. The strong influence of o -phenyl groups of the ligand on the enantioselectivities of the reaction has been demonstrated by a comparison with its parent ligand MeO-BIPHEP.