Asymmetric Hydrogenation of Bicyclic Ketones Catalyzed by BINAP/IPHAN−Ru(II) Complex

Hydrogenation of 3-quinuclidinone and bicyclo[2.2.2]octan-2-one with a combined catalyst system of RuCl₂[(S)-binap][(R)-iphan] and t-C₄H₉OK in 2-propanol afforded the chiral alcohols in 97−98% ee. 2-Diphenylmethyl-3-quinuclidinone was hydrogenated with the same catalyst to the cis alcohol with perfect diastereo- and enantioselectivity. The reaction of unsymmetrical ketones with a bicyclo[2.2.1] or -[2.2.2] skeleton gave the corresponding alcohols with high stereoselectivity.