Regioselective hydrogenation of 2,3 pentanedione was investigated over poly ( N vinyl 2 pyrrolidone) stabilized platinum nanoclusters (PVP Pt) with metal cation as modifier. The results indicated that the addition of ...Regioselective hydrogenation of 2,3 pentanedione was investigated over poly ( N vinyl 2 pyrrolidone) stabilized platinum nanoclusters (PVP Pt) with metal cation as modifier. The results indicated that the addition of metal cations as well as the increase of solvent polarity could enhance the regioselectivity for 3 hydroxy 2 pentanone. The use of Sn 2+ could remarkably activate the hydrogenation reaction while the use of Ce 3+ decreased the reaction activity greatly. The modification effect was explained by the toxic effect of metal cations on the metal catalyst, the polarization effect of metal cations on the carbonyl group and the steric effect of the substrate itself.展开更多
Molybdenum (VI) complex, namely molybdenum dioxobis(2,4-pentanedione) [MoO2(acac)2] used as epoxidation catalyst species, was synthesized and characterized by elemental analysis and infrared spectrum. Polystyrene-supp...Molybdenum (VI) complex, namely molybdenum dioxobis(2,4-pentanedione) [MoO2(acac)2] used as epoxidation catalyst species, was synthesized and characterized by elemental analysis and infrared spectrum. Polystyrene-supported molybdenum dioxobis(2,4-pentanedione) [MoO2(acac)2] for synthesis of epoxycyclohexane was prepared by phase transfer catalysis method. Effects of various factors in synthesis of epoxycyclohexane by reaction of cyclohexene and t-BuOOH in the atmosphere of nitrogen catalyzed by polystyrene-supported MoO2(acac)2 were also investigated. Under the following conditions, n(cyclohexene):n(t-BuOOH)=3.5:l (based on 0.1 mol of t-BuOOH), volume of solvent -10ml, reaction temperature -80℃, reaction time -60min, and mass of molybdenum in the catalyst -2.30×0^(-3)g, the yield of epoxycyclohexane on the basis of t-BuOOH is over 99.5%, and the purity of epoxycyclohexane is about 99.9% by gas chromatogram(GC) analysis.展开更多
A new and efficient way was developed to carry out the reaction of acetylacetone with aryl iodides under the assistance of Cu（II） and 1, 1＇-trimethylene-2,2＇-biimidazole at 100℃. 3-Aryl-2,4-pentanediones were obt...A new and efficient way was developed to carry out the reaction of acetylacetone with aryl iodides under the assistance of Cu（II） and 1, 1＇-trimethylene-2,2＇-biimidazole at 100℃. 3-Aryl-2,4-pentanediones were obtained in excellent yields.展开更多
文摘Regioselective hydrogenation of 2,3 pentanedione was investigated over poly ( N vinyl 2 pyrrolidone) stabilized platinum nanoclusters (PVP Pt) with metal cation as modifier. The results indicated that the addition of metal cations as well as the increase of solvent polarity could enhance the regioselectivity for 3 hydroxy 2 pentanone. The use of Sn 2+ could remarkably activate the hydrogenation reaction while the use of Ce 3+ decreased the reaction activity greatly. The modification effect was explained by the toxic effect of metal cations on the metal catalyst, the polarization effect of metal cations on the carbonyl group and the steric effect of the substrate itself.
基金Supported by the Outstanding Personality Innovation Funds of Henan Province(No.0121001900).
文摘Molybdenum (VI) complex, namely molybdenum dioxobis(2,4-pentanedione) [MoO2(acac)2] used as epoxidation catalyst species, was synthesized and characterized by elemental analysis and infrared spectrum. Polystyrene-supported molybdenum dioxobis(2,4-pentanedione) [MoO2(acac)2] for synthesis of epoxycyclohexane was prepared by phase transfer catalysis method. Effects of various factors in synthesis of epoxycyclohexane by reaction of cyclohexene and t-BuOOH in the atmosphere of nitrogen catalyzed by polystyrene-supported MoO2(acac)2 were also investigated. Under the following conditions, n(cyclohexene):n(t-BuOOH)=3.5:l (based on 0.1 mol of t-BuOOH), volume of solvent -10ml, reaction temperature -80℃, reaction time -60min, and mass of molybdenum in the catalyst -2.30×0^(-3)g, the yield of epoxycyclohexane on the basis of t-BuOOH is over 99.5%, and the purity of epoxycyclohexane is about 99.9% by gas chromatogram(GC) analysis.
基金Project supported by tile National Natural Science Foundation of China （No. 20772088）.Acknowledgements We would like to thank good suggestions from Ma, Dawei of Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, China.
文摘A new and efficient way was developed to carry out the reaction of acetylacetone with aryl iodides under the assistance of Cu（II） and 1, 1＇-trimethylene-2,2＇-biimidazole at 100℃. 3-Aryl-2,4-pentanediones were obtained in excellent yields.
