Transition-metal-catalyzed asymmetric reduction of prochiral ketones is one of the most intensive subjects in organic synthesis.[1, 2] Among a variety of systems for the catalytic reduction, ruthenium-catalyzed hydrogenation, and transfer hydrogenation of prochiral ketones have been developed and used as reliable synthetic methods to obtain reduced alcohols with a highto-excellent enantioselectivity.[1, 2] We have also reported the ...
