Visible light‐driven carboxylation with CO_(2) have emerged as a sustainable and powerful way to transfer waste to treasure.However,it is still challenging for aryl fluorides due to the low reactivities of both C(sp2...Visible light‐driven carboxylation with CO_(2) have emerged as a sustainable and powerful way to transfer waste to treasure.However,it is still challenging for aryl fluorides due to the low reactivities of both C(sp2)−F bonds and CO_(2).Herein,we report the first photocatalytic carboxylation of aryl C−F bonds with CO_(2).The visible‐light photoredox catalysis enables selective carboxylation of strong C(sp2)−F bonds in diverse polyluoroarenes,such as penta‐,tetra‐,and tri‐fluoroarenes under mild conditions,providing a facile access to a series of important polyfluoroaryl carboxylic acids with good yields.In contrast to previous reports of direct capture of polyfluoroaryl radicals,mechanistic studies suggest that the reduction of fleeting polyfluoroaryl radicals into polyfluoroaryl anions might be involved in this transformation,which may open a new avenue for photocatalytic functionalization of aryl C−F bonds.展开更多
A nickel-catalyzed reductive cross-coupling reactions between polyfluoroarenes and alkyl electrophiles is reported to access substituted fluoroarenes through chelation-assisted C–F activation.Diverse primary and seco...A nickel-catalyzed reductive cross-coupling reactions between polyfluoroarenes and alkyl electrophiles is reported to access substituted fluoroarenes through chelation-assisted C–F activation.Diverse primary and secondary alkyl(pseudo)halides can be employed to couple with polyfluoroarenes,showing excellent regioselectivity.Furthermore,the nickel-catalyzed asymmetric cross-coupling of polyfluoroarenes with racemic alkyl halides is preliminarily explored.In addition,the practicability of the title transformation is also demonstrated by total synthesis of losmapimod and an analog as key steps.The developed method exhibits many advantages,including economic catalytic systems,commercially available alkyl electrophiles,and lack of sensitive organometallic reagents.展开更多
An effective and facile method for preparation of partially fluorinated aromatics via Nickel catalyzed, chelation-assisted ortho selective hydrodefluorination of polyfluoroames with triethylsilane has been developed, ...An effective and facile method for preparation of partially fluorinated aromatics via Nickel catalyzed, chelation-assisted ortho selective hydrodefluorination of polyfluoroames with triethylsilane has been developed, in which N-containing heterocycles were used as directing groups. The advantage of this protocol is its simple catalytic system with use of inexpensive and readily available NiCl2·6H2O as a catalyst.展开更多
文摘Visible light‐driven carboxylation with CO_(2) have emerged as a sustainable and powerful way to transfer waste to treasure.However,it is still challenging for aryl fluorides due to the low reactivities of both C(sp2)−F bonds and CO_(2).Herein,we report the first photocatalytic carboxylation of aryl C−F bonds with CO_(2).The visible‐light photoredox catalysis enables selective carboxylation of strong C(sp2)−F bonds in diverse polyluoroarenes,such as penta‐,tetra‐,and tri‐fluoroarenes under mild conditions,providing a facile access to a series of important polyfluoroaryl carboxylic acids with good yields.In contrast to previous reports of direct capture of polyfluoroaryl radicals,mechanistic studies suggest that the reduction of fleeting polyfluoroaryl radicals into polyfluoroaryl anions might be involved in this transformation,which may open a new avenue for photocatalytic functionalization of aryl C−F bonds.
基金the National Natural Science Foundation of China (Nos. 22025104, 21972064 and 21901111)the National Natural Science Foundation of Jiangsu Province (No. BK20170632)+2 种基金the Excellent Youth Foundation of Jiangsu Scientific Committee (No. BK20180007)the “Innovation & Entrepreneurship Talents Plan” of Jiangsu Provincethe Fundamental Research Funds for the Central Universities for their financial support
文摘A nickel-catalyzed reductive cross-coupling reactions between polyfluoroarenes and alkyl electrophiles is reported to access substituted fluoroarenes through chelation-assisted C–F activation.Diverse primary and secondary alkyl(pseudo)halides can be employed to couple with polyfluoroarenes,showing excellent regioselectivity.Furthermore,the nickel-catalyzed asymmetric cross-coupling of polyfluoroarenes with racemic alkyl halides is preliminarily explored.In addition,the practicability of the title transformation is also demonstrated by total synthesis of losmapimod and an analog as key steps.The developed method exhibits many advantages,including economic catalytic systems,commercially available alkyl electrophiles,and lack of sensitive organometallic reagents.
文摘An effective and facile method for preparation of partially fluorinated aromatics via Nickel catalyzed, chelation-assisted ortho selective hydrodefluorination of polyfluoroames with triethylsilane has been developed, in which N-containing heterocycles were used as directing groups. The advantage of this protocol is its simple catalytic system with use of inexpensive and readily available NiCl2·6H2O as a catalyst.
