Highly active and stable magnetic copper catalysts were successfully achieved by magnetic induced Stober method and subsequent hydrothermal reaction with copper ions in alkaline condition.The high content of Cu2+as we...Highly active and stable magnetic copper catalysts were successfully achieved by magnetic induced Stober method and subsequent hydrothermal reaction with copper ions in alkaline condition.The high content of Cu2+as well as the unique structures of hierarchical copper silicate in the as-prepared catalysts endowed their outstanding catalytic performance.Efficient decarboxylative A3-coupling of a-keto acid,amine and alkyne was realized with the low Fe3 O4@CuSiO3 loading.A range of propargylamines were produced in good to excellent yields under solvent-free condition.Moreover,the catalyst can be easily separated from the final organic product with an external magnet.Also,this kind of catalyst could be recycled up to six times while maintaining its activity.展开更多
An assembly of Keggin polyoxomolybdate and organic substrate （Hbipy）3[PM01204o] （1, bipy = 2,2＇- bipyridine） was synthesized and characterized by elemental analysis, infrared spectrum, and single- crystal X-ray a...An assembly of Keggin polyoxomolybdate and organic substrate （Hbipy）3[PM01204o] （1, bipy = 2,2＇- bipyridine） was synthesized and characterized by elemental analysis, infrared spectrum, and single- crystal X-ray analysis. The ligand bipy of compound 1 was generated by a decarboxylation coupling reaction of H2pdc （H2pdc = pyridine-2,6-dicarboxylic acid） in situ under hydrothermal reaction conditions and the control experiments illustrate that La（NO3）3 or Ce（NO3）3, which does not appear in the final structure, is necessary for the decarboxylation coupling reaction. Moreover, compound 1 displays strong photoluminescence property in the solid state at room temperature.展开更多
In this study,the preparation of economical Cu-based catalysts for Pd-free coupling and oxidation reactions was demonstrated.For the preparation of the Cu-based catalyst,first,a Cu-BTC MOF was prepared under ambient c...In this study,the preparation of economical Cu-based catalysts for Pd-free coupling and oxidation reactions was demonstrated.For the preparation of the Cu-based catalyst,first,a Cu-BTC MOF was prepared under ambient conditions.The Cu-BTC MOF was then carbonized in N_(2) to obtain Cu-Cu_(2)O-supported carbon materials.Moreover,the Cu-Cu_(2)O-supported carbon material was subjected to heating in O_(2) to obtain the CuO-Cu_(2)O-supported carbon material.Formation of Cu-BTC-MOF,Cu-Cu_(2)O,and CuO-Cu_(2)O was confirmed via powder X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).The amount and types of carbon present in the catalyst were confirmed using thermogravimetric analysis and Raman spectroscopy,respectively.The textural properties of the materials were determined using N_(2)-sorption measurement.The morphology,porosity,and elemental composition were confirmed via the scanning and transmission electron microscopy images.The Cu-Cu_(2)O-supported carbon material successfully catalyzed the Sonogashira cross-coupling(C-C cross-coupling reaction),Ullmann amination(C-N coupling reaction),and A^(3) coupling(decarboxylative C-C and C-N coupling)reactions;moreover,the CuO-Cu_(2)O-supported carbon material successfully oxidized diphenylmethane in O_(2) at 1 atm.The catalysts were found to be stable and recyclable.Heterogeneity of the reaction was confirmed via the CS_(2) poisoning and hot-filtration tests.The presence of the optimum amount and the suitable oxidation state of Cu in the stable nanoporous carbon matrix having graphitic conducting nature were responsible for the excellent activity and recyclability.The results demonstrate that the applications of these Cu-based catalysts can be extended to several catalytic reactions that are known to be catalyzed using Pd and other costly metals.展开更多
A copper-catalyzed decarboxylative oxidative coupling of α,β-unsaturated carboxylic acids with non-cyclic ethers is developed.This method provides a new approach for C(sp^3)–H bond functionalization of non-cyclic e...A copper-catalyzed decarboxylative oxidative coupling of α,β-unsaturated carboxylic acids with non-cyclic ethers is developed.This method provides a new approach for C(sp^3)–H bond functionalization of non-cyclic ethers. Mechanism study shows the reaction involves a radical process.展开更多
Indenophenanthrenes have remained largely overlooked as photocatalysts because their intrinsically high exciton binding energies and low molar absorption coefficients restrict both light-harvesting efficiency and sing...Indenophenanthrenes have remained largely overlooked as photocatalysts because their intrinsically high exciton binding energies and low molar absorption coefficients restrict both light-harvesting efficiency and single-electron transfer(SET)capability.In this work,we introduce a twisted indenophenanthrene derivative that overcomes these long-standing limitations through intentional distortion of its π-conjugated framework.The resulting nonplanar geometry enhances light absorption and substantially decreases electron-hole pair binding energy,thereby enabling efficient photoinduced SET for the first time within this molecular family.This structurally engineered chromophore functions as a robust metal-free photoredox catalyst.Its catalytic performance was validated through a prototypical decarboxylative coupling reaction between α-amino acids and electron-deficient alkenes.Under mild visible-light irradiation,the catalyst delivers the desired C-C bond-forming products in high yields across a broad substrate scope.A wide range of natural and synthetic amino acids,as well as diverse alkene acceptors,are well tolerated,demonstrating the generality and versatility of this newly developed catalyst platform.Mechanistic studies comprising radical trapping,fluorescence quenching,Stern-Volmer analysis,and a series of control experiments collectively provide compelling evidence for an oxidative quenching pathway mediated by radical intermediates.Over-all,this study establishes a modular design principle for engineering the photophysical and electrochemical properties of purely organic photocatalysts through geometric twisting.By demonstrating that twisted indenophenanthrenes can mediate challenging redox transformations under mild,metal-free conditions,this work positions them as a promising new class of sustainable organic photoredox catalysts for advanced synthetic applications.展开更多
An efficient and eco-friendly carbon nitride nanosheet(NM-g-C3N4)-catalyzed decarboxylative coupling reaction of imidazo-fused heterocycles(i.e.,imidazo[1,2-a]pyridines,benzo[d]imidazo[2,1-b]thiazole)with N-phenylglyc...An efficient and eco-friendly carbon nitride nanosheet(NM-g-C3N4)-catalyzed decarboxylative coupling reaction of imidazo-fused heterocycles(i.e.,imidazo[1,2-a]pyridines,benzo[d]imidazo[2,1-b]thiazole)with N-phenylglycines in dimethyl carbonate(DMC)has been developed.The toxic solvents,external oxidants,and restricted reaction conditions could be effectively avoided in this powerful and sustainable protocol.Remarkably,NM-g-C3N4 could be straightforwardly recovered by simple centrifugation and recycled and reused at least 7 times without an obvious decrease in catalytic activity.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21601121,21305086)the Natural Science Foundation of Shanghai(No.18ZR1416400)+1 种基金support of the Shanghai University of Engineering Science(Nos.201810856017,A1-0601-19-01017)the Opening Project of Shanghai Key Laboratory of Chemical Biology for financial support。
文摘Highly active and stable magnetic copper catalysts were successfully achieved by magnetic induced Stober method and subsequent hydrothermal reaction with copper ions in alkaline condition.The high content of Cu2+as well as the unique structures of hierarchical copper silicate in the as-prepared catalysts endowed their outstanding catalytic performance.Efficient decarboxylative A3-coupling of a-keto acid,amine and alkyne was realized with the low Fe3 O4@CuSiO3 loading.A range of propargylamines were produced in good to excellent yields under solvent-free condition.Moreover,the catalyst can be easily separated from the final organic product with an external magnet.Also,this kind of catalyst could be recycled up to six times while maintaining its activity.
基金supported by the National Natural Science Foundation of China(Nos.21173021,21231002, 21276026,20801036,51002180)the 111 Project(No. B07012)the Program of Cooperation of the Beijing Education Commission(No.20091739006)
文摘An assembly of Keggin polyoxomolybdate and organic substrate （Hbipy）3[PM01204o] （1, bipy = 2,2＇- bipyridine） was synthesized and characterized by elemental analysis, infrared spectrum, and single- crystal X-ray analysis. The ligand bipy of compound 1 was generated by a decarboxylation coupling reaction of H2pdc （H2pdc = pyridine-2,6-dicarboxylic acid） in situ under hydrothermal reaction conditions and the control experiments illustrate that La（NO3）3 or Ce（NO3）3, which does not appear in the final structure, is necessary for the decarboxylation coupling reaction. Moreover, compound 1 displays strong photoluminescence property in the solid state at room temperature.
文摘In this study,the preparation of economical Cu-based catalysts for Pd-free coupling and oxidation reactions was demonstrated.For the preparation of the Cu-based catalyst,first,a Cu-BTC MOF was prepared under ambient conditions.The Cu-BTC MOF was then carbonized in N_(2) to obtain Cu-Cu_(2)O-supported carbon materials.Moreover,the Cu-Cu_(2)O-supported carbon material was subjected to heating in O_(2) to obtain the CuO-Cu_(2)O-supported carbon material.Formation of Cu-BTC-MOF,Cu-Cu_(2)O,and CuO-Cu_(2)O was confirmed via powder X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).The amount and types of carbon present in the catalyst were confirmed using thermogravimetric analysis and Raman spectroscopy,respectively.The textural properties of the materials were determined using N_(2)-sorption measurement.The morphology,porosity,and elemental composition were confirmed via the scanning and transmission electron microscopy images.The Cu-Cu_(2)O-supported carbon material successfully catalyzed the Sonogashira cross-coupling(C-C cross-coupling reaction),Ullmann amination(C-N coupling reaction),and A^(3) coupling(decarboxylative C-C and C-N coupling)reactions;moreover,the CuO-Cu_(2)O-supported carbon material successfully oxidized diphenylmethane in O_(2) at 1 atm.The catalysts were found to be stable and recyclable.Heterogeneity of the reaction was confirmed via the CS_(2) poisoning and hot-filtration tests.The presence of the optimum amount and the suitable oxidation state of Cu in the stable nanoporous carbon matrix having graphitic conducting nature were responsible for the excellent activity and recyclability.The results demonstrate that the applications of these Cu-based catalysts can be extended to several catalytic reactions that are known to be catalyzed using Pd and other costly metals.
基金supported by the National Natural Science Foundation of China (21572240)
文摘A copper-catalyzed decarboxylative oxidative coupling of α,β-unsaturated carboxylic acids with non-cyclic ethers is developed.This method provides a new approach for C(sp^3)–H bond functionalization of non-cyclic ethers. Mechanism study shows the reaction involves a radical process.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0540000)the National Natural Science Foundation of China(22271268)for financial support.
文摘Indenophenanthrenes have remained largely overlooked as photocatalysts because their intrinsically high exciton binding energies and low molar absorption coefficients restrict both light-harvesting efficiency and single-electron transfer(SET)capability.In this work,we introduce a twisted indenophenanthrene derivative that overcomes these long-standing limitations through intentional distortion of its π-conjugated framework.The resulting nonplanar geometry enhances light absorption and substantially decreases electron-hole pair binding energy,thereby enabling efficient photoinduced SET for the first time within this molecular family.This structurally engineered chromophore functions as a robust metal-free photoredox catalyst.Its catalytic performance was validated through a prototypical decarboxylative coupling reaction between α-amino acids and electron-deficient alkenes.Under mild visible-light irradiation,the catalyst delivers the desired C-C bond-forming products in high yields across a broad substrate scope.A wide range of natural and synthetic amino acids,as well as diverse alkene acceptors,are well tolerated,demonstrating the generality and versatility of this newly developed catalyst platform.Mechanistic studies comprising radical trapping,fluorescence quenching,Stern-Volmer analysis,and a series of control experiments collectively provide compelling evidence for an oxidative quenching pathway mediated by radical intermediates.Over-all,this study establishes a modular design principle for engineering the photophysical and electrochemical properties of purely organic photocatalysts through geometric twisting.By demonstrating that twisted indenophenanthrenes can mediate challenging redox transformations under mild,metal-free conditions,this work positions them as a promising new class of sustainable organic photoredox catalysts for advanced synthetic applications.
基金the financial support from the National Natural Science Foundation of China(Nos.21971224,22171249)the Natural Science Foundation of Henan Provinee,China(No.202300410375)the College Students'Innovation and Entre-preneurship Training Program of Zhengzhou University(No.2021cxcy197).
文摘An efficient and eco-friendly carbon nitride nanosheet(NM-g-C3N4)-catalyzed decarboxylative coupling reaction of imidazo-fused heterocycles(i.e.,imidazo[1,2-a]pyridines,benzo[d]imidazo[2,1-b]thiazole)with N-phenylglycines in dimethyl carbonate(DMC)has been developed.The toxic solvents,external oxidants,and restricted reaction conditions could be effectively avoided in this powerful and sustainable protocol.Remarkably,NM-g-C3N4 could be straightforwardly recovered by simple centrifugation and recycled and reused at least 7 times without an obvious decrease in catalytic activity.
