Well-Defined Triflylamide-Tethered Arene−Ru(Tsdpen) Complexes for Catalytic Asymmetric Hydrogenation of Ketones

Well-defined triflylamide-tethered arene−Ru(Tsdpen) complexes have been developed as highly efficient catalysts for the asymmetric hydrogenation of ketones, in which the suitable carbon chain length of the tether is responsible for the activation of H2 as well as the stereochemical outcome of the reaction. The asymmetric hydrogenation of aromatic ketones with the tethered complex with a C4 side chain gave the corresponding secondary alcohols with 91−98% ee, while the shorter congeners with a C2 or C3 side chain provided unsatisfactory results in terms of reactivity and selectivity.