10.1021/jp106405s.s001 Linmin Ye Linmin Ye Haiqiang Lin Haiqiang Lin Hancheng Zhou Hancheng Zhou Youzhu Yuan Youzhu Yuan Support and Size Effects of Ruthenium Catalysts with a Chiral Modifier for Asymmetric Hydrogenation of Aromatic Ketones American Chemical Society 2010 achiral modifier triphenylphosphine hydrogenation Ru nanoparticle diameter TPP 2O 6.2 nm nanoparticle diameter ee value Aromatic KetonesA series NH N 2 physisorption CO catalyst transmission electron microscopy oxide spectroscopy 2010-11-25 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Support_and_Size_Effects_of_Ruthenium_Catalysts_with_a_Chiral_Modifier_for_Asymmetric_Hydrogenation_of_Aromatic_Ketones/2709835 A series of supported Ru catalysts with achiral modifier triphenylphosphine (TPP) and chiral modifier (1<i>R</i>,2<i>R</i>)-1,2-diphenylethylenediamine [(1<i>R</i>,2<i>R</i>)-DPEN] were employed for the asymmetric hydrogenation of aromatic ketones. The textural and structural properties of the catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, N<sub>2</sub> physisorption, transmission electron microscopy, CO<sub>2</sub> and NH<sub>3</sub> temperature-programmed desorptions, inductively coupled plasma atomic emission spectrometry, and ultraviolet−visible spectroscopy. Studies revealed that the enantiomeric excess (ee) followed this order according to the oxide supports used: MgO > γ-Al<sub>2</sub>O<sub>3</sub> > CeO<sub>2</sub> ≫ ZnO > SiO<sub>2</sub>, which was correlated with their surface basicity. Moreover, the highest ee value and intrinsic activity for the asymmetric hydrogenation of acetophenone were attained over the catalyst with a mean Ru nanoparticle diameter of 4.4 nm, while those for the asymmetric hydrogenation of 1-acetonaphthone were obtained over a catalyst with 6.2 nm nanoparticle diameter. The catalyst system consisting of Ru/MgO, TPP, and (1<i>R</i>,2<i>R</i>)-DPEN did not show a significant decrease in ee value after several recycles. The results indicate that there is a size matching effect between the Ru particles and the substrates, besides the acid/base influence of the oxide supports on the reaction.