Asymmetric Hydrogenation of Ketones Catalyzed by Ruthenium Hydride Complexes of a Beta-aminophosphine Ligand Derived from Norephedrine GuoRongwei LoughAlan J. MorrisRobert H. SongDatong 2004 A series ruthenium complexes with the chiral P−N ligand (1<i>R,</i>2<i>R</i>)-PPh<sub>2</sub>CHPhCHMeNH<sub>2</sub> derived from (1<i>S,</i>2<i>R</i>)-norephedrine are synthesized starting from the complexes RuHCl(PPh<sub>3</sub>)<sub>3</sub> or RuHCl(P−P)(PPh<sub>3</sub>) (P−P= (<i>R</i>)-binap or (<i>S</i>)-binap). These are precatalysts for the efficient asymmetric hydrogenation of simple ketones. For the hydrogenation of acetophenone to 1-phenylethanol, the enantioselectivity observed can be related to the structure of the precatalysts determined by X-ray diffraction. This relationship breaks down for the hydrogenation of pinacolone.