The combination of a zinc phthalocyanine(ZnPc)catalyst and a stoichiometric amount of dimethyl formamide(DMF)provided a simple route to formamide derivatives from amines,CO2,and hydrosilanes under mild conditions.We d...The combination of a zinc phthalocyanine(ZnPc)catalyst and a stoichiometric amount of dimethyl formamide(DMF)provided a simple route to formamide derivatives from amines,CO2,and hydrosilanes under mild conditions.We deduced that formation of an active zinc‐hydrogen(Zn‐H)species promoted hydride transfer from the hydrosilane to CO2.The cooperative activation of the Lewis acidic ZnPc by strongly polar DMF,led to formation of activated amines and hydrosilanes,which promoted the chemical reduction of CO2.Consequently,the binary ZnPc/DMF catalytic system showed excellent yields and superior chemoselectivity,representing a simple and sustainable pathway for the reductive transformation of CO2into valuable chemicals as an alternative to conventional halogen‐containing process.展开更多
Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated ...Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated for the case of selective alkylarene oxidation by molecular oxygen.The proposed catalytic system consists of two widely available components:N-hydroxyphthalimide(NHPI,a homogeneous organocatalyst for free-radical chain reactions)and nanosized TiO_(2)(heterogeneous UV-active photoredox catalyst).The interaction of NHPI with TiO_(2) allows for a shift from UV to visible light photoredox activity and generation of phthalimide-N-oxyl(PINO)radicals that diffuse into the solution where NHPI/PINO-catalyzed free-radical chain reaction can proceed without the additional light input providing a fundamental increase in energy efficiency.The NHPI/TiO_(2) ratio controls the selectivity of oxidation affording preferential formation of hydroperoxide or ketone from alkylarene.展开更多
Nano‐catalysis plays a vital role in the chemical transformations and significantly impacts the booming modern chemical industry.The rapid technological enhancements have resulted in serious energy and environmental ...Nano‐catalysis plays a vital role in the chemical transformations and significantly impacts the booming modern chemical industry.The rapid technological enhancements have resulted in serious energy and environmental issues,which are currently spurring the exploration of the novel nano‐catalysts in diverse fields.In order to develop the efficient nano‐catalysts,it is essential to understand their fundamental physicochemical properties,including the coordination structures of the active centers and substrate‐adsorbate interactions.Subsequently,the nano‐catalyst design with precise manipulation at the atomic level can be attained.In this account,we have summarized our extensive investigation of the factors impacting nano‐catalysis,along with the synthetic strategies developed to prepare the nano‐catalysts for applications in electrocatalysis,photocatalysis and thermocatalysis.Finally,a brief conclusion and future research directions on nano‐catalysis have also been presented.展开更多
Selective oxidation with molecular oxygen as the sole oxidant under mild conditions is of crucialimportance for the long‐term sustainable exploitation of available feedstocks and the formation ofrequired intermediate...Selective oxidation with molecular oxygen as the sole oxidant under mild conditions is of crucialimportance for the long‐term sustainable exploitation of available feedstocks and the formation ofrequired intermediates for organic synthesis and industrial processes.Among the developed oxidationprotocols,innovative strategies using hydroxyimide organocatalysts in combination with metallicor metal‐free cocatalysts have attracted much attention because of the good activities andselectivities of such catalysts in the oxo functionalization of hydrocarbons.This method is based onthe reaction using N‐hydroxyphthalimide,which was first reported by Ishii’s group in the1990s.Although the important and wide‐ranging applications of such catalysts have been summarizedrecently,there are no reviews that focus solely on oxidation strategies using multi‐nitroxy organocatalysts,which have interesting properties and high reactivities.This review covers the concisesynthetic methods and mechanistic profiles of known multi‐nitroxy organocatalysts and summarizessignificant advances in their use in efficient aerobic oxidation.Based on a combination of experimentaland theoretical results,guidelines for the future rational design of multi‐nitroxy organocatalystsare proposed,and the properties of various model multi‐nitroxy organocatalysts are predicted.The present overview of the advantages,limitations,and potential applications of multi‐nitroxyorganocatalysts can provide useful tools for researchers in the field of selective oxidation.展开更多
Carboxylate as a promising and valuable directing group has attracted a great deal of attention.However,employing it as a traceless direction group has rarely been reported.We developed the ruthenium-catalyzed amidati...Carboxylate as a promising and valuable directing group has attracted a great deal of attention.However,employing it as a traceless direction group has rarely been reported.We developed the ruthenium-catalyzed amidation of substituted benzoic acids with isocyanates via directed C–H functionalization followed by decarboxylation to afford the corresponding metasubstituted N-aryl benzamides,in which the carboxylate serves as a unique,removable directing group.Notably,this protocol can provide an efficient alternative to access meta-substituted N-aryl benzamides,which are much more difficult to prepare than ortho-substituted analogues.展开更多
A novel phthalocyanine, 2,9（10）,16（17）,23（24）-tetra（4-benzoyl）phenoxyphthalocyanine, and its complexes with Zn（Ⅱ）, Cu（Ⅱ）, Co（Ⅱ）, and Ni（Ⅱ） have been synthesized and characterized by a combination o...A novel phthalocyanine, 2,9（10）,16（17）,23（24）-tetra（4-benzoyl）phenoxyphthalocyanine, and its complexes with Zn（Ⅱ）, Cu（Ⅱ）, Co（Ⅱ）, and Ni（Ⅱ） have been synthesized and characterized by a combination of elemental analysis, IR, IH NMR, UV-vis spectroscopy and mass spectrometry. All of the materials are very soluble in common organic solvents such as dichloro- methane, chloroform, tetrahydrofuran, N,N-dimethylformamide and dimethyl sulfoxide. The Q band wavelengths of the com- plexes decrease in the order： Zn 〉 Cu 〉 Ni 〉 Co. Redox processes were observed at -1.06, -0.74, 0.51 and 0.98 V for the free phthalocyanine, at -0.72 and 1.04 V for the Co（Ⅱ） complex, at -1.24, -0.77, -0.24, 0.61 and 0,91 V for the Cu（Ⅱ） complex, and at -0.74 and 1.20 V for the Ni（Ⅱ） complex. The cyclic voltammograms of the phthalocyanine ring of the four species are similar, with reduction and oxidation couples each involving a one-electron transfer process.展开更多
基金supported by the National Natural Science Foundation of China (21676306,21425627)the National Key Research and Development Program of China (2016YFA0602900)+1 种基金the Natural Science Foundation of Guangdong Province (2016A030310211)the Characteristic Innovation Project (Natural Science) of Guangdong Colleges and Universities~~
文摘The combination of a zinc phthalocyanine(ZnPc)catalyst and a stoichiometric amount of dimethyl formamide(DMF)provided a simple route to formamide derivatives from amines,CO2,and hydrosilanes under mild conditions.We deduced that formation of an active zinc‐hydrogen(Zn‐H)species promoted hydride transfer from the hydrosilane to CO2.The cooperative activation of the Lewis acidic ZnPc by strongly polar DMF,led to formation of activated amines and hydrosilanes,which promoted the chemical reduction of CO2.Consequently,the binary ZnPc/DMF catalytic system showed excellent yields and superior chemoselectivity,representing a simple and sustainable pathway for the reductive transformation of CO2into valuable chemicals as an alternative to conventional halogen‐containing process.
文摘Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated for the case of selective alkylarene oxidation by molecular oxygen.The proposed catalytic system consists of two widely available components:N-hydroxyphthalimide(NHPI,a homogeneous organocatalyst for free-radical chain reactions)and nanosized TiO_(2)(heterogeneous UV-active photoredox catalyst).The interaction of NHPI with TiO_(2) allows for a shift from UV to visible light photoredox activity and generation of phthalimide-N-oxyl(PINO)radicals that diffuse into the solution where NHPI/PINO-catalyzed free-radical chain reaction can proceed without the additional light input providing a fundamental increase in energy efficiency.The NHPI/TiO_(2) ratio controls the selectivity of oxidation affording preferential formation of hydroperoxide or ketone from alkylarene.
文摘Nano‐catalysis plays a vital role in the chemical transformations and significantly impacts the booming modern chemical industry.The rapid technological enhancements have resulted in serious energy and environmental issues,which are currently spurring the exploration of the novel nano‐catalysts in diverse fields.In order to develop the efficient nano‐catalysts,it is essential to understand their fundamental physicochemical properties,including the coordination structures of the active centers and substrate‐adsorbate interactions.Subsequently,the nano‐catalyst design with precise manipulation at the atomic level can be attained.In this account,we have summarized our extensive investigation of the factors impacting nano‐catalysis,along with the synthetic strategies developed to prepare the nano‐catalysts for applications in electrocatalysis,photocatalysis and thermocatalysis.Finally,a brief conclusion and future research directions on nano‐catalysis have also been presented.
基金supported by the China Postdoctoral Science Foundation (2014M551746)~~
文摘Selective oxidation with molecular oxygen as the sole oxidant under mild conditions is of crucialimportance for the long‐term sustainable exploitation of available feedstocks and the formation ofrequired intermediates for organic synthesis and industrial processes.Among the developed oxidationprotocols,innovative strategies using hydroxyimide organocatalysts in combination with metallicor metal‐free cocatalysts have attracted much attention because of the good activities andselectivities of such catalysts in the oxo functionalization of hydrocarbons.This method is based onthe reaction using N‐hydroxyphthalimide,which was first reported by Ishii’s group in the1990s.Although the important and wide‐ranging applications of such catalysts have been summarizedrecently,there are no reviews that focus solely on oxidation strategies using multi‐nitroxy organocatalysts,which have interesting properties and high reactivities.This review covers the concisesynthetic methods and mechanistic profiles of known multi‐nitroxy organocatalysts and summarizessignificant advances in their use in efficient aerobic oxidation.Based on a combination of experimentaland theoretical results,guidelines for the future rational design of multi‐nitroxy organocatalystsare proposed,and the properties of various model multi‐nitroxy organocatalysts are predicted.The present overview of the advantages,limitations,and potential applications of multi‐nitroxyorganocatalysts can provide useful tools for researchers in the field of selective oxidation.
基金supported by the National Natural Science Foundation of China(20906059,21272145)the Shaanxi Innovative Team of Key Science and Technology(2013KCT-17)+1 种基金the Fundamental Research Funds for the Central Universities(GK201503030,GK261001095)the 111 Project,and Canada Research Chair(to CJL)
文摘Carboxylate as a promising and valuable directing group has attracted a great deal of attention.However,employing it as a traceless direction group has rarely been reported.We developed the ruthenium-catalyzed amidation of substituted benzoic acids with isocyanates via directed C–H functionalization followed by decarboxylation to afford the corresponding metasubstituted N-aryl benzamides,in which the carboxylate serves as a unique,removable directing group.Notably,this protocol can provide an efficient alternative to access meta-substituted N-aryl benzamides,which are much more difficult to prepare than ortho-substituted analogues.
基金supported by the Application Foundation of the Science and Technology Office of Jilin Province (20080901)the Fundamental Research Funds for the Central Universities (09SSXT030)
文摘A novel phthalocyanine, 2,9（10）,16（17）,23（24）-tetra（4-benzoyl）phenoxyphthalocyanine, and its complexes with Zn（Ⅱ）, Cu（Ⅱ）, Co（Ⅱ）, and Ni（Ⅱ） have been synthesized and characterized by a combination of elemental analysis, IR, IH NMR, UV-vis spectroscopy and mass spectrometry. All of the materials are very soluble in common organic solvents such as dichloro- methane, chloroform, tetrahydrofuran, N,N-dimethylformamide and dimethyl sulfoxide. The Q band wavelengths of the com- plexes decrease in the order： Zn 〉 Cu 〉 Ni 〉 Co. Redox processes were observed at -1.06, -0.74, 0.51 and 0.98 V for the free phthalocyanine, at -0.72 and 1.04 V for the Co（Ⅱ） complex, at -1.24, -0.77, -0.24, 0.61 and 0,91 V for the Cu（Ⅱ） complex, and at -0.74 and 1.20 V for the Ni（Ⅱ） complex. The cyclic voltammograms of the phthalocyanine ring of the four species are similar, with reduction and oxidation couples each involving a one-electron transfer process.
