Highly efficient asymmetric transfer hydrogenation of ketones catalyzed by chiral 'roofed' cis-diamine-Ru(II) complex

A new type of chiral Ru(II) complex, prepared from a conformationally rigid, sterically bulky 'roofed' cis-diamine and [RuCl2(benzene)]2, functions as an efficient catalyst for the asymmetric transfer hydrogenation of a wide variety of aryl ketones, including sterically bulky ketones, when the reaction is conducted in the presence of 5HCO2H·2NEt3.