The N-formylation of amines with CO_(2)and hydrosilanes is an emerging yet important reaction in fine chemical industry.Herein,we have reported a methyltrioctylammonium cation(TOMA)stabilized Nb oxocluster catalyst th...The N-formylation of amines with CO_(2)and hydrosilanes is an emerging yet important reaction in fine chemical industry.Herein,we have reported a methyltrioctylammonium cation(TOMA)stabilized Nb oxocluster catalyst that can effectively realize two electron reduction of CO_(2)and form C-N bond simultaneously,leading to the corresponding formamides.The oxocluster catalyst exhibits excellent catalytic activity to transform secondary and primary amines into the corresponding formamides,with the conversion ranging from 81.5%to 99.2%under room temperature conditions.Furthermore,the Nb oxocluster catalyst shows the unique characteristics of ionic liquids,and it is highly robust and easy to be recycled for five times with negligible loss of catalytic activity.On the basis of the activity tests and structure characterization of Nb catalysts,it was found that TOMA cation played an important role in modulating the Nb oxocluster with high stability and uniform dispersion.The mechanism studies demonstrate that the formylation reaction proceeds through the formation of silyl formate intermediate rather than carbamate,and the Lewis base site of negative oxygen atoms from polyoxoniobate anions can exert a favorable impact on activation both CO_(2)and Si-H bond of PhSiH 3,allowing that N-formylation reaction proceed smoothly under very mild reaction conditions.展开更多
The selective conversion of CO_(2)and NH_(3)into valuable nitriles presents significant potential for CO_(2)utilization.In this study,we exploited the synergistic interplay between silicon and fluoride to augment the ...The selective conversion of CO_(2)and NH_(3)into valuable nitriles presents significant potential for CO_(2)utilization.In this study,we exploited the synergistic interplay between silicon and fluoride to augment the nickel-catalyzed reductive cyanation of aryl pseudohalides containing silyl groups,utilizing CO_(2)and NH_(3)as the CN source.Our methodology exhibited exceptional compatibility with diverse functional groups,such as alcohols,ketones,ethers,esters,nitriles,olefins,pyridines,and quinolines,among others,as demonstrated by the successful synthesis of 58 different nitriles.Notably,we achieved high yields in the preparation of bifunctionalized molecules,including intermediates for perampanel,derived from osilylaryl triflates,which are well-known as aryne precursors.Remarkably,no degradation of substrates or formation of aryne intermediates were observed.Mechanistic studies imply that the formation of pentacoordinated silyl isocyanate intermediates is crucial for the key C-C coupling step and the presence of vicinal silyl group in the substrate is beneficial to further make this step kinetically favorable.展开更多
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
Terminal monohaloalkenes are common synthetic fragments used in organic synthesis and are also found in many natural products.Their Z/E stereoisomers are difficult to physically separate,being a persistent difficulty ...Terminal monohaloalkenes are common synthetic fragments used in organic synthesis and are also found in many natural products.Their Z/E stereoisomers are difficult to physically separate,being a persistent difficulty for functional molecular design and synthesis.Herein,we report complementary hydride and hydrogen radical generation pathways to effectuate hydrodehalogenation and deuterodehalogenation of gem-dihaloalkenes,producing stereo-defined deuterated or nondeuterated(Z)-and(E)-terminal monofluoroalkenes and(E)-terminal monochloroalkenes.Our methods have broad substrate scopes and good functional group tolerance.Mechanistic studies and density functional theory calculations elucidate the stereoselectivity.展开更多
基金The authors are grateful for financial support from the National Natural Science Foundation of China(21773061,21978095).
文摘The N-formylation of amines with CO_(2)and hydrosilanes is an emerging yet important reaction in fine chemical industry.Herein,we have reported a methyltrioctylammonium cation(TOMA)stabilized Nb oxocluster catalyst that can effectively realize two electron reduction of CO_(2)and form C-N bond simultaneously,leading to the corresponding formamides.The oxocluster catalyst exhibits excellent catalytic activity to transform secondary and primary amines into the corresponding formamides,with the conversion ranging from 81.5%to 99.2%under room temperature conditions.Furthermore,the Nb oxocluster catalyst shows the unique characteristics of ionic liquids,and it is highly robust and easy to be recycled for five times with negligible loss of catalytic activity.On the basis of the activity tests and structure characterization of Nb catalysts,it was found that TOMA cation played an important role in modulating the Nb oxocluster with high stability and uniform dispersion.The mechanism studies demonstrate that the formylation reaction proceeds through the formation of silyl formate intermediate rather than carbamate,and the Lewis base site of negative oxygen atoms from polyoxoniobate anions can exert a favorable impact on activation both CO_(2)and Si-H bond of PhSiH 3,allowing that N-formylation reaction proceed smoothly under very mild reaction conditions.
基金the National Natural Science Foundation of China(Nos.22072167,22202218)the Jiangsu Natural Science Funds for Young Scholar(No.BK20211093)is greatly appreciated.
文摘The selective conversion of CO_(2)and NH_(3)into valuable nitriles presents significant potential for CO_(2)utilization.In this study,we exploited the synergistic interplay between silicon and fluoride to augment the nickel-catalyzed reductive cyanation of aryl pseudohalides containing silyl groups,utilizing CO_(2)and NH_(3)as the CN source.Our methodology exhibited exceptional compatibility with diverse functional groups,such as alcohols,ketones,ethers,esters,nitriles,olefins,pyridines,and quinolines,among others,as demonstrated by the successful synthesis of 58 different nitriles.Notably,we achieved high yields in the preparation of bifunctionalized molecules,including intermediates for perampanel,derived from osilylaryl triflates,which are well-known as aryne precursors.Remarkably,no degradation of substrates or formation of aryne intermediates were observed.Mechanistic studies imply that the formation of pentacoordinated silyl isocyanate intermediates is crucial for the key C-C coupling step and the presence of vicinal silyl group in the substrate is beneficial to further make this step kinetically favorable.
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.
基金support from the National Natural Science Foundation of China(grant nos.22293011 and 22371273)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(grant no.2023476)+1 种基金the National Science Foundation of Anhui Province(grant no.2208085J26)the New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘Terminal monohaloalkenes are common synthetic fragments used in organic synthesis and are also found in many natural products.Their Z/E stereoisomers are difficult to physically separate,being a persistent difficulty for functional molecular design and synthesis.Herein,we report complementary hydride and hydrogen radical generation pathways to effectuate hydrodehalogenation and deuterodehalogenation of gem-dihaloalkenes,producing stereo-defined deuterated or nondeuterated(Z)-and(E)-terminal monofluoroalkenes and(E)-terminal monochloroalkenes.Our methods have broad substrate scopes and good functional group tolerance.Mechanistic studies and density functional theory calculations elucidate the stereoselectivity.
