A copper-catalyzed three-component reaction of alkenes,cycloketone oximes and DABCO·(SO_(2))_(2) is de-veloped,which provides a convenient route for the synthesis of diverse(E)-cyanoalkylsulfonyl alkenes in moder...A copper-catalyzed three-component reaction of alkenes,cycloketone oximes and DABCO·(SO_(2))_(2) is de-veloped,which provides a convenient route for the synthesis of diverse(E)-cyanoalkylsulfonyl alkenes in moderate to good yields with excellent regio-and stereoselectivity.A broad substrate scope with ex-cellent functional group tolerance is observed.A plausible radical pathway is proposed,which involves copper-catalyzed ring-opening C–C bond cleavage of O-acyl oxime and insertion of sulfur dioxide.During the reaction process,cyanoalkyl radical and cyanoalkylsulfonyl radical are the key intermediates.展开更多
β-Chiral sulfones are structural motifs widely found in natural products and bioactive molecules, while also serving as important intermediates for the synthesis of valuable chiral scaffolds. In contrast to the rapid...β-Chiral sulfones are structural motifs widely found in natural products and bioactive molecules, while also serving as important intermediates for the synthesis of valuable chiral scaffolds. In contrast to the rapid growth of sulfur dioxide insertion chemistry over the last decade, enantioselective catalytic variants for accessing β-chiral sulfones, especially those bearing a quaternary carbon stereocenter, remain rare. Herein, we report an enantioselective copper/bisoxazoline catalyzed oxysulfonylation of alkenes to yield isoxazolinyl-containing β-chiral sulfones bearing quaternary carbon stereocenters with moderate to excellent yields and up to 96:4 er. The advantage and irreplaceability of this sulfur dioxide insertion catalytic system have been demonstrated by achieving transformations clearly unavailable with the previously reported sulfonyl chloride system. Additionally,the recoverability of the new-developed bisoxazoline ligand L9 and its reusability without any erosion of the catalytic activity and enantioselectivity further demonstrate the usefulness of the protocol.展开更多
基金support from the National Natural Science Foundation of China (No. 21871053)the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang (No. 2019R01005)the Open Research Fund of School of Chemistry and Chemical Engineering, Henan Normal University (No. 2020ZD04) is gratefully acknowledged
文摘A copper-catalyzed three-component reaction of alkenes,cycloketone oximes and DABCO·(SO_(2))_(2) is de-veloped,which provides a convenient route for the synthesis of diverse(E)-cyanoalkylsulfonyl alkenes in moderate to good yields with excellent regio-and stereoselectivity.A broad substrate scope with ex-cellent functional group tolerance is observed.A plausible radical pathway is proposed,which involves copper-catalyzed ring-opening C–C bond cleavage of O-acyl oxime and insertion of sulfur dioxide.During the reaction process,cyanoalkyl radical and cyanoalkylsulfonyl radical are the key intermediates.
基金supported by the National Natural Science Foundation of China(22171206)the Natural Science Foundation of Zhejiang Province(Z23B020002,LY22B020003,)+1 种基金the Open Foundation of Hunan Provincial Key Laboratory of Controllable Preparation and Functional Application of Fine Polymers(E22307)the Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University(2020ZD04)。
文摘β-Chiral sulfones are structural motifs widely found in natural products and bioactive molecules, while also serving as important intermediates for the synthesis of valuable chiral scaffolds. In contrast to the rapid growth of sulfur dioxide insertion chemistry over the last decade, enantioselective catalytic variants for accessing β-chiral sulfones, especially those bearing a quaternary carbon stereocenter, remain rare. Herein, we report an enantioselective copper/bisoxazoline catalyzed oxysulfonylation of alkenes to yield isoxazolinyl-containing β-chiral sulfones bearing quaternary carbon stereocenters with moderate to excellent yields and up to 96:4 er. The advantage and irreplaceability of this sulfur dioxide insertion catalytic system have been demonstrated by achieving transformations clearly unavailable with the previously reported sulfonyl chloride system. Additionally,the recoverability of the new-developed bisoxazoline ligand L9 and its reusability without any erosion of the catalytic activity and enantioselectivity further demonstrate the usefulness of the protocol.
