asymmetric transfer hydrogenation of unsymmetricalbenzils with m, p-substituents was conducted with a substrate/catalyst molar ratio of 100 at 40 °C for 24 h to produce (S,S)-hydrobenzoins in good yields (76.2% to 97.1%) with high diastereomeric (syn/anti = 10.8 to 29.7/1) and enantiomeric purities (86.1%ee syn to 98.9%ee syn). Unfortunately, the unsymmetricalbenzils with the o-substituents such as electron-donating