An efficient route for the palladium-catalyzed reductive aminocarbonylation of olefins with nitroarenes was developed using carbon monoxide(CO)as both reductant and carbonyl source,which enables facile access to amide...An efficient route for the palladium-catalyzed reductive aminocarbonylation of olefins with nitroarenes was developed using carbon monoxide(CO)as both reductant and carbonyl source,which enables facile access to amides with excellent regioselectivity and broad substrate scope.It is found that the counter anions of the Pd catalyst precursors significantly affect the reaction chemoselectivity and amide regioselectivity.Branched amides were mainly obtained with K2PdCl4 as the metal catalyst,and phosphine ligands had no influence on the regioselectivity but affected the catalytic reactivity.However,phosphine ligands had significant effects on aminocarbonylation regioselectivity when Pd(CH3CN)4(OTf)2 was used;monodentate phosphines tended to form branched amides,and bidentate phosphines mainly formed linear amides.Trapping experiments,primary kinetic studies,and control reactions with all possible N-species reduced from nitroarene indicated that the catalytic synthesis of branched and linear amides produced nitrene(further converted to enamide)and aniline,respectively,different from the previous ligand-controlled regioselective synthesis of amides via the aminocarbonylation of olefins with amines.Furthermore,the proposed synthesis route could be applied in the synthesis of gram-scale propanil under mild conditions.展开更多
A series of metal chlorides supported solid catalysts were prepared by simple wet impregnation method. Their catalytic performances for Friedel-Crafts acylation of toluene with benzoyl chloride were evaluated and the ...A series of metal chlorides supported solid catalysts were prepared by simple wet impregnation method. Their catalytic performances for Friedel-Crafts acylation of toluene with benzoyl chloride were evaluated and the excellent results were obtained over FeC13/SiO2. These catalysts were characterized by BET, NH3-TPD and FT-IR of pyridine adsorption to clarify the structure-activity relationship. It was found that FeC13/SiO2 has larger pore size and pore volume than other catalysts, which increased the accessibility of the catalyst. In addition, FeC13/SiO2 ex- hibited higher molar ratio of Lewis acid sites and Brtpnsted acid sites, which might be another reason for the in- crease of toluene conversion. Furthermore, the reaction parameters, including temperature, time and molar ratio, were optimized. Under the optimized conditions, 91.2% conversion and 82.0% selectivity were obtained. Mean- while, the generality of the catalyst was demonstrated by the acylations of alkyl substituted aromatics. Finally, the catalyst was reused for four runs with slight loss in catalytic activity, which attributed to the drain of the active component.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
Based on the polycondensation of bifunctional 2,2′-diamino-4,4′-bithiazole(DABT) and trifunctional 1,3,5-benzenetricarbonyl trichloride (BTC),a novel hyperbranched aromatic polyamide PBD was synthesized with excelle...Based on the polycondensation of bifunctional 2,2′-diamino-4,4′-bithiazole(DABT) and trifunctional 1,3,5-benzenetricarbonyl trichloride (BTC),a novel hyperbranched aromatic polyamide PBD was synthesized with excellent solubility and good thermal stability.The structure of the polymer was confirmed by FT-IR and 1H NMR spectrum.The calculated degree of branching of our product was 52%.By exploring the influence of several different solvent systems,the yield of the polymer increased in the solvent system of DMAc/LiCl.Two kinds of metal complexes were obtained by chelation of the polyamide with Cu2+ and Ni2+,and the metal contents of the complexes were determined by complexometric titration.The magnetic behaviors of the complexes were examined as a function of magnetic field strength at 5 K,and as a function of temperature (5–300 K) at a magnetic field strength of 2.4 × 106 A/m.The results indicated that the complexes were soft ferromagnetic materials with Curie-Weiss temperature at 102 K and 53 K,respectively.展开更多
A new radical-mediated method for the synthesis of 1-(2-(1,2-diarylvinyl)phenyl)ethan-1-ones by the redox hydroarylation of o-(hydroxyalkyl)arylalkynes with arylsulfonyl chlorides is described. This visible light cata...A new radical-mediated method for the synthesis of 1-(2-(1,2-diarylvinyl)phenyl)ethan-1-ones by the redox hydroarylation of o-(hydroxyalkyl)arylalkynes with arylsulfonyl chlorides is described. This visible light catalysis method proceeds via a sequence of the radical addition of aryl group across the C?C triple bond, protonation and redox reaction, and represents a new redox transformation reaction directed by a neighboring hydroxyl group.展开更多
An efficient approach for the synthesis of N-arylated amides was developed via copper(Ⅱ) triflate-catalyzed direct oxidation of(aryl)methylamines to primary arylamides by air and subsequent N-arylation by diaryliodon...An efficient approach for the synthesis of N-arylated amides was developed via copper(Ⅱ) triflate-catalyzed direct oxidation of(aryl)methylamines to primary arylamides by air and subsequent N-arylation by diaryliodonium salts. Various substituted benzylamines could be applied in the reaction, providing a series of N-arylated amides in moderate to good yields. This method showed convenient, practical, and environment friendly advantages.展开更多
文摘An efficient route for the palladium-catalyzed reductive aminocarbonylation of olefins with nitroarenes was developed using carbon monoxide(CO)as both reductant and carbonyl source,which enables facile access to amides with excellent regioselectivity and broad substrate scope.It is found that the counter anions of the Pd catalyst precursors significantly affect the reaction chemoselectivity and amide regioselectivity.Branched amides were mainly obtained with K2PdCl4 as the metal catalyst,and phosphine ligands had no influence on the regioselectivity but affected the catalytic reactivity.However,phosphine ligands had significant effects on aminocarbonylation regioselectivity when Pd(CH3CN)4(OTf)2 was used;monodentate phosphines tended to form branched amides,and bidentate phosphines mainly formed linear amides.Trapping experiments,primary kinetic studies,and control reactions with all possible N-species reduced from nitroarene indicated that the catalytic synthesis of branched and linear amides produced nitrene(further converted to enamide)and aniline,respectively,different from the previous ligand-controlled regioselective synthesis of amides via the aminocarbonylation of olefins with amines.Furthermore,the proposed synthesis route could be applied in the synthesis of gram-scale propanil under mild conditions.
基金Supported by the National Basic Research Program of China("973"Program,No.21476163)
文摘A series of metal chlorides supported solid catalysts were prepared by simple wet impregnation method. Their catalytic performances for Friedel-Crafts acylation of toluene with benzoyl chloride were evaluated and the excellent results were obtained over FeC13/SiO2. These catalysts were characterized by BET, NH3-TPD and FT-IR of pyridine adsorption to clarify the structure-activity relationship. It was found that FeC13/SiO2 has larger pore size and pore volume than other catalysts, which increased the accessibility of the catalyst. In addition, FeC13/SiO2 ex- hibited higher molar ratio of Lewis acid sites and Brtpnsted acid sites, which might be another reason for the in- crease of toluene conversion. Furthermore, the reaction parameters, including temperature, time and molar ratio, were optimized. Under the optimized conditions, 91.2% conversion and 82.0% selectivity were obtained. Mean- while, the generality of the catalyst was demonstrated by the acylations of alkyl substituted aromatics. Finally, the catalyst was reused for four runs with slight loss in catalytic activity, which attributed to the drain of the active component.
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 National Natural Science Foundation of China (20674071)the National Basic Research Program of China (973 Program,2005CB623800)
文摘Based on the polycondensation of bifunctional 2,2′-diamino-4,4′-bithiazole(DABT) and trifunctional 1,3,5-benzenetricarbonyl trichloride (BTC),a novel hyperbranched aromatic polyamide PBD was synthesized with excellent solubility and good thermal stability.The structure of the polymer was confirmed by FT-IR and 1H NMR spectrum.The calculated degree of branching of our product was 52%.By exploring the influence of several different solvent systems,the yield of the polymer increased in the solvent system of DMAc/LiCl.Two kinds of metal complexes were obtained by chelation of the polyamide with Cu2+ and Ni2+,and the metal contents of the complexes were determined by complexometric titration.The magnetic behaviors of the complexes were examined as a function of magnetic field strength at 5 K,and as a function of temperature (5–300 K) at a magnetic field strength of 2.4 × 106 A/m.The results indicated that the complexes were soft ferromagnetic materials with Curie-Weiss temperature at 102 K and 53 K,respectively.
基金supported by the National Natural Science Foundation of China(2140204621172060+1 种基金21472039)the Fundamental Research Funds for the Central Universities
文摘A new radical-mediated method for the synthesis of 1-(2-(1,2-diarylvinyl)phenyl)ethan-1-ones by the redox hydroarylation of o-(hydroxyalkyl)arylalkynes with arylsulfonyl chlorides is described. This visible light catalysis method proceeds via a sequence of the radical addition of aryl group across the C?C triple bond, protonation and redox reaction, and represents a new redox transformation reaction directed by a neighboring hydroxyl group.
基金This work was financially supported by the National Nature Science Foundation of China(21272069,20672035)the Fundamental Reearch Funds for the Central Universities and Key Laboratory of Organofluorine Chemistry,Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences.
文摘An efficient approach for the synthesis of N-arylated amides was developed via copper(Ⅱ) triflate-catalyzed direct oxidation of(aryl)methylamines to primary arylamides by air and subsequent N-arylation by diaryliodonium salts. Various substituted benzylamines could be applied in the reaction, providing a series of N-arylated amides in moderate to good yields. This method showed convenient, practical, and environment friendly advantages.
