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NH/π Attraction: A Role in Asymmetric Hydrogenation of Aromatic Ketones with Binap/1,2-Diamine-Ruthenium(II) Complexes



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Role model: Electrostatic NHeq/π attraction plays an important role in asymmetric hydrogenation of acetophenones catalyzed by chiral [RuX2(diphosphine)(1,2-diamine)] complexes. The relative rate of p-substituted ketones bears a Hammett linear relationship with ρ=1.03 but with a notable exception for the p-fluoro ketone. The enantioselectivity is enhanced by an electron-donating p substituent and is decreased by an electron donor.