Polymer-immobilized catalysis has many advantages such as easy recovery and reuse of catalyst. We prepared three novel chiral 1,1＇-bi-2-naphthol-Ti coordination polymers with properly designed ligands and Ti（O^ipr）...Polymer-immobilized catalysis has many advantages such as easy recovery and reuse of catalyst. We prepared three novel chiral 1,1＇-bi-2-naphthol-Ti coordination polymers with properly designed ligands and Ti（O^ipr）4 under mild conditions. The prepared polymers exhibited good activity and excellent enantioselectivity （over 99%ee） in catalyzing the asymmetric oxidation of sulfides. The bridge linker in the polymer and the reaction solvent noticeably affected the enantioseleetivity. The chiral coordination polymer was very stable and easy to separate from catalyzed reaction systems, with no significant loss of activity or enantioselectivity after reuse for at least ten times. These findings suggest a promising type of catalysts for synthesizing the widely used sulfoxides by asymmetrically oxidizing sulfides.展开更多
Immobilizing chiral 1,1＇-bi-2-naphthol （BINOL） in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic...Immobilizing chiral 1,1＇-bi-2-naphthol （BINOL） in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic asymmetric oxidation of sulfide to sulfoxide exhibited good activity （up to 60% yield） and high enantioselectivity （up to 89% ee）. The immobilized chiral catalyst was very stable and could be readily reused for over 5 times without significant loss of catalytic activity and enantioselectivity.展开更多
This work reported a convenient method for the preparation of enantiomerically pure 6-aryl-2,2＇-dihydroxy-1, l＇- binaphthyl derivatives starting from the commercially available （R）-2,2＇-hydroxy-l, l＇-binaphthyl ...This work reported a convenient method for the preparation of enantiomerically pure 6-aryl-2,2＇-dihydroxy-1, l＇- binaphthyl derivatives starting from the commercially available （R）-2,2＇-hydroxy-l, l＇-binaphthyl [（R）-I] via bromi- nation, hydrolysis and Suzuki cross coupling reaction. This novel synthetie method was characterized with high re- gioselectivity, simple operation, mild reaction conditions, and excellent yield （up to 73%）. On the other hand, we synthesized the target unknown compounds, which were confirmed by IR, 1H NMR, 13C NMR, MS and elementary analysis.展开更多
基金the Natural Science Foundation of Chongqing Science and Technology Committee (No.2007BB4442)the Science and Technology Research Project of Chongqing Education Commission (No.KJ070402)
文摘Polymer-immobilized catalysis has many advantages such as easy recovery and reuse of catalyst. We prepared three novel chiral 1,1＇-bi-2-naphthol-Ti coordination polymers with properly designed ligands and Ti（O^ipr）4 under mild conditions. The prepared polymers exhibited good activity and excellent enantioselectivity （over 99%ee） in catalyzing the asymmetric oxidation of sulfides. The bridge linker in the polymer and the reaction solvent noticeably affected the enantioseleetivity. The chiral coordination polymer was very stable and easy to separate from catalyzed reaction systems, with no significant loss of activity or enantioselectivity after reuse for at least ten times. These findings suggest a promising type of catalysts for synthesizing the widely used sulfoxides by asymmetrically oxidizing sulfides.
文摘Immobilizing chiral 1,1＇-bi-2-naphthol （BINOL） in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic asymmetric oxidation of sulfide to sulfoxide exhibited good activity （up to 60% yield） and high enantioselectivity （up to 89% ee）. The immobilized chiral catalyst was very stable and could be readily reused for over 5 times without significant loss of catalytic activity and enantioselectivity.
文摘This work reported a convenient method for the preparation of enantiomerically pure 6-aryl-2,2＇-dihydroxy-1, l＇- binaphthyl derivatives starting from the commercially available （R）-2,2＇-hydroxy-l, l＇-binaphthyl [（R）-I] via bromi- nation, hydrolysis and Suzuki cross coupling reaction. This novel synthetie method was characterized with high re- gioselectivity, simple operation, mild reaction conditions, and excellent yield （up to 73%）. On the other hand, we synthesized the target unknown compounds, which were confirmed by IR, 1H NMR, 13C NMR, MS and elementary analysis.
