Atropisomeric 5, 5′-linked biphenyl bisaminophosphine ligands 2 has been synthesized. The axial chirality of this type of ligands can be retained by macro-ring strain produced from 5, 5′-linkage of biphenyl even without 6, 6′-substituents on biphenyls. The Rh complex of bisaminophosphine 2a as a catalyst is effectively working in the asymmetric hydrogenation of methyl (Z)-2-acetamido-3-arylacrylates, however, for hydrogenation of arylenamide, the ...