A chiral ferrocene-tethered ruthenium diamine catalyst for asymmetric transfer hydrogenation of ketones†

A chiral ferrocene-tethered ruthenium diamine catalyst has been developed for asymmetric transfer hydrogenation of ketones, enabling asymmetric reduction of a wide range of ketones including aryl alkyl ketones and cyclic dialkyl ketones with excellent reactivities and enantioselectivities. Efficient dynamic kinetic resolution (DKR) of racemic α-substituted cyclic ketones was established, affording a series of cyclic chiral alcohols with two contiguous stereocenters in high yields and excellent enantio- and diastereoselectivity levels. The chiral ATH Ru catalyst was found to offer practicality, with a TON of up to 4000.