Copper hydride-catalyzed conjugate reduction-intermolecular aldol addition domino reactions were realized using α,β-unsaturated carboxylates as hydride acceptors and a silane as the reducing reagent. High diastereos...Copper hydride-catalyzed conjugate reduction-intermolecular aldol addition domino reactions were realized using α,β-unsaturated carboxylates as hydride acceptors and a silane as the reducing reagent. High diastereoselec- tivities were achieved with 4,5-bis（diphenylphosphino）-9,9-dimethylxanthene as the ligand and tert-butyl acrylate as the hydride acceptor.展开更多
Despite the paramount applications of organofluorine compounds in life and materials sciences,efficient strategies for stereoselectively constructing the C(sp^(3))-CF_(2)R bond at the stereogenic center remain limited...Despite the paramount applications of organofluorine compounds in life and materials sciences,efficient strategies for stereoselectively constructing the C(sp^(3))-CF_(2)R bond at the stereogenic center remain limited.Here,we report a copper-catalyzed hydrodifluoroallylation of cyclopropenes and alkenyl boronates with 3,3-difluoroallyl sulfonium salts(DFASs).The use of DFASs overcomes the previous challenge of suppressing the reduction of fluoroalkylating reagents with M-H species.The reaction provides an array of gem-difluoroallyl cyclopropanes and borylalkanes with high efficiency and stereoselectivity under mild reaction conditions.Using chiral phosphine ligand could provide gem-difluoroallyl borylalkanes with high enantioselectivities,paving a new way for the catalytic asymmetric fluoroalkylation with ubiquitous alkenes.The advantages of this protocol are synthetic convenience,high functional group tolerance,and the synthetic versatility of the resulting gem-difluoroallyl cyclopropanes and borylalkanes.The synthetic utility of this approach has also been demonstrated by the diversified transformations of the gem-difluoroallylated products and the rapid synthesis of bioactive molecule analogs.展开更多
Intramolecular conjugate reduction-aldol addition reactions of β＇-oxoalkyl a,fl-unsaturated carboxylates were performed in the presence of copper catalysts generated in situ from copper salts, phosphine ligands and ...Intramolecular conjugate reduction-aldol addition reactions of β＇-oxoalkyl a,fl-unsaturated carboxylates were performed in the presence of copper catalysts generated in situ from copper salts, phosphine ligands and silanes. Moderate to good yields and high diastereoselectivities were obtained in 15 min to 3 h using bis[（2-diphenyl- phosphino）phenyl] ether as the ligand.展开更多
文摘Copper hydride-catalyzed conjugate reduction-intermolecular aldol addition domino reactions were realized using α,β-unsaturated carboxylates as hydride acceptors and a silane as the reducing reagent. High diastereoselec- tivities were achieved with 4,5-bis（diphenylphosphino）-9,9-dimethylxanthene as the ligand and tert-butyl acrylate as the hydride acceptor.
基金Financial support for this work was provided by the National Key R&D Program of China(2021YFF0701700)the National Natural Science Foundation of China(21931013,22193072)the Science and Technology Committee of Shanghai Municipality(22JC1403500,21XD1404400).
文摘Despite the paramount applications of organofluorine compounds in life and materials sciences,efficient strategies for stereoselectively constructing the C(sp^(3))-CF_(2)R bond at the stereogenic center remain limited.Here,we report a copper-catalyzed hydrodifluoroallylation of cyclopropenes and alkenyl boronates with 3,3-difluoroallyl sulfonium salts(DFASs).The use of DFASs overcomes the previous challenge of suppressing the reduction of fluoroalkylating reagents with M-H species.The reaction provides an array of gem-difluoroallyl cyclopropanes and borylalkanes with high efficiency and stereoselectivity under mild reaction conditions.Using chiral phosphine ligand could provide gem-difluoroallyl borylalkanes with high enantioselectivities,paving a new way for the catalytic asymmetric fluoroalkylation with ubiquitous alkenes.The advantages of this protocol are synthetic convenience,high functional group tolerance,and the synthetic versatility of the resulting gem-difluoroallyl cyclopropanes and borylalkanes.The synthetic utility of this approach has also been demonstrated by the diversified transformations of the gem-difluoroallylated products and the rapid synthesis of bioactive molecule analogs.
基金We are grateful to the National Natural Science Foundation of China for financial support （No. 20972020）.
文摘Intramolecular conjugate reduction-aldol addition reactions of β＇-oxoalkyl a,fl-unsaturated carboxylates were performed in the presence of copper catalysts generated in situ from copper salts, phosphine ligands and silanes. Moderate to good yields and high diastereoselectivities were obtained in 15 min to 3 h using bis[（2-diphenyl- phosphino）phenyl] ether as the ligand.
