Highly efficient chiral PNNP ligand for asymmetric transfer hydrogenation of aromatic ketones in water

Chiral PNNP ligand II and [IrHCl2(COD)]2 were applied for the first time in the asymmetric transfer hydrogenation of aromatic ketones with HCOONa in water, giving the corresponding optical alcohols in high yield and excellent enantioselectivity (up to 99% ee). Particularly, the reduction of propiophenone proceeded smoothly at a substrate to catalyst molar ratio of 8000, without compromising the ee values obtained.