 The stoichiometric asymmetric reduction of ketones has long been known, but a practical catalytic version was introduced by Noyori et al.While the BINAP-Ru dicarboxylate could only efficiently catalyze the hydrogenation of olefins, the BINAP-Ru dihalide could catalyze both the hydrogenation of olefins and the hydrogenation of functionalized C=O bond.Even though the BINAP-Ru dihalide catalyst could reduce functionalized ketones, the hydrogenation of simple ketones has remained a challenge.