TiO_2 nanoparticles（TiO_2 NPs） worked as an efficient heterogeneous catalyst in a one-pot,three-component,and solvent free Mannich reaction;producing variousβ-aminocarbonyls in good yields,and with good stereoselec...TiO_2 nanoparticles（TiO_2 NPs） worked as an efficient heterogeneous catalyst in a one-pot,three-component,and solvent free Mannich reaction;producing variousβ-aminocarbonyls in good yields,and with good stereoselectivities.The catalyst was easily separated from the reaction mixture and was recycled four times with no significant loss of its catalytic activity.展开更多
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
The discovery of a rearrangement reaction of 5-amino-1-arylaminocarbonyl-1,2,triazole(pyrszole)to 5-arylureylene-1,2,4-trazole and the mechanism for thisrearrangement reaction are presented. The rearrangement reaction...The discovery of a rearrangement reaction of 5-amino-1-arylaminocarbonyl-1,2,triazole(pyrszole)to 5-arylureylene-1,2,4-trazole and the mechanism for thisrearrangement reaction are presented. The rearrangement reaction could be attributed to athermodynamic energy preference leading to the predominant formation of 5-aryluretjlene1,2,4-triazole,as shown by molecular mechanics calculation with MMX Program.展开更多
α,β-Unsaturated primary amides are important intermediates and building blocks in organic synthesis.Herein,we report a ligand-free iron-catalyzed hydroaminocarbonylation of alkynes using NH_(4)HCO_(3)as the ammonia ...α,β-Unsaturated primary amides are important intermediates and building blocks in organic synthesis.Herein,we report a ligand-free iron-catalyzed hydroaminocarbonylation of alkynes using NH_(4)HCO_(3)as the ammonia source,enabling the highly efficient and regioselective synthesis of linearα,β-unsaturated primary amides.Various aromatic and aliphatic alkynes are transformed into the desired linearα,β-unsaturated primary amides in good to excellent yields.Further studies show that using NH_(4)HCO_(3)as the ammonia source is key to obtain good yields and selectivity.The utility of this route is demonstrated with the synthesis of linearα,β-unsaturated amides including vanilloid receptor-1 antagonist TRPV-1.展开更多
Catalytic four-component radical carbonylation of unactivated alkenes has recently been recognized as a robust protocol for rapid construction of various structurally diverse carbonyl compounds.Given the significance ...Catalytic four-component radical carbonylation of unactivated alkenes has recently been recognized as a robust protocol for rapid construction of various structurally diverse carbonyl compounds.Given the significance of fluorine-containing groups,this reaction class has been extensively applied to assembly of a variety of perfluoroalkyl carboxylic acid derivatives by transition metal catalysis.Herein,we report a visible-light-driven radical relay 1,2-perfluoroalkylation aminocarbonylation of unactivated alkenes using CO gas as carbonyl source and 4CzIPN as organic photocatalyst.A wide range of alkenes and amines were well tolerated,providing the valuableβ-perfluoroalkylated amides with generally good yields and high chemoselectivity.展开更多
A regioselective C-C bond cleavage/aminocarbonylation cascade is presented. In recent years, tremendous progress has been made in the alkoxyl radical-mediated C-C bond cleavage of unstrained monocarbocycles. In contra...A regioselective C-C bond cleavage/aminocarbonylation cascade is presented. In recent years, tremendous progress has been made in the alkoxyl radical-mediated C-C bond cleavage of unstrained monocarbocycles. In contrast, the deconstruction and functionalization of bicyclic skeletons has been less developed and has mainly focused on the ring expansion process. Inspired by the aromatization-driven C-C bond cleavage, here we demonstrate a ring-opening/aminocarbonylation cascade under copper catalysis, in which the formation of a stable γ-lactam or succinimide skeleton reverses the selectivity of C-C cleavage. Remarkably, the photo and thermal assistance is not required when the succinimide skeleton is formed during the ring opening process. DFT calculations revealed that this unexpected ring-opening process is thermodynamically and kinetically favourable.展开更多
Carbonylation reactions,crucial for carbonyl group incorporation,struggle with the inherent complexity of achieving selective mono-or double-carbonylation on single substrates,often due to competing reaction pathways....Carbonylation reactions,crucial for carbonyl group incorporation,struggle with the inherent complexity of achieving selective mono-or double-carbonylation on single substrates,often due to competing reaction pathways.Herein,our study introduces a strategy employing palladium amides,harnessing their unique reactivity control,to direct the selective carbonylation of amines for the targeted synthesis of urea and oxamide derivatives.The palladium amide structure was elucidated using single-crystal X-ray diffraction.Controlled experiments and cyclic voltammetry studies further elucidate that the oxidation of palladium amide or its insertion into a carbonyl group diverges into distinct pathways.By employing sodium percarbonate as an eco-friendly oxidant and base,we have successfully constructed a switchable carbonylation system co-catalyzed by palladium and iodide under room temperature.The utilizing strategy in this study not only facilitates effective control over reaction selectivity but also mitigates the risk of explosions,a critical safety concern in traditional carbonylation methods.展开更多
文摘TiO_2 nanoparticles（TiO_2 NPs） worked as an efficient heterogeneous catalyst in a one-pot,three-component,and solvent free Mannich reaction;producing variousβ-aminocarbonyls in good yields,and with good stereoselectivities.The catalyst was easily separated from the reaction mixture and was recycled four times with no significant loss of its catalytic activity.
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.
文摘The discovery of a rearrangement reaction of 5-amino-1-arylaminocarbonyl-1,2,triazole(pyrszole)to 5-arylureylene-1,2,4-trazole and the mechanism for thisrearrangement reaction are presented. The rearrangement reaction could be attributed to athermodynamic energy preference leading to the predominant formation of 5-aryluretjlene1,2,4-triazole,as shown by molecular mechanics calculation with MMX Program.
基金financial supports from the National Natural Science Foundation of China(Nos.21772035,22022204,22072167,21202206)Natural Science Foundation of Hunan Province(Nos.2021JJ40147)。
文摘α,β-Unsaturated primary amides are important intermediates and building blocks in organic synthesis.Herein,we report a ligand-free iron-catalyzed hydroaminocarbonylation of alkynes using NH_(4)HCO_(3)as the ammonia source,enabling the highly efficient and regioselective synthesis of linearα,β-unsaturated primary amides.Various aromatic and aliphatic alkynes are transformed into the desired linearα,β-unsaturated primary amides in good to excellent yields.Further studies show that using NH_(4)HCO_(3)as the ammonia source is key to obtain good yields and selectivity.The utility of this route is demonstrated with the synthesis of linearα,β-unsaturated amides including vanilloid receptor-1 antagonist TRPV-1.
基金the financial support from the National Natural Science Foundation of China(21971081,22171099,21820102003,91956201,22203034,and 92256301)the Double-Thousand Talents Plan of Jiangxi Province(jxsq2023102004)+1 种基金the Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University(2021YB02)and the Program of Introducing Talents of Discipline to Universities of China(111 Program,B17019).
文摘Catalytic four-component radical carbonylation of unactivated alkenes has recently been recognized as a robust protocol for rapid construction of various structurally diverse carbonyl compounds.Given the significance of fluorine-containing groups,this reaction class has been extensively applied to assembly of a variety of perfluoroalkyl carboxylic acid derivatives by transition metal catalysis.Herein,we report a visible-light-driven radical relay 1,2-perfluoroalkylation aminocarbonylation of unactivated alkenes using CO gas as carbonyl source and 4CzIPN as organic photocatalyst.A wide range of alkenes and amines were well tolerated,providing the valuableβ-perfluoroalkylated amides with generally good yields and high chemoselectivity.
基金supported by the National Natural Science Foundation of China (Nos. 22171220)the Fundamental Research Funds of the Central Universities (No. xtr072022003)。
文摘A regioselective C-C bond cleavage/aminocarbonylation cascade is presented. In recent years, tremendous progress has been made in the alkoxyl radical-mediated C-C bond cleavage of unstrained monocarbocycles. In contrast, the deconstruction and functionalization of bicyclic skeletons has been less developed and has mainly focused on the ring expansion process. Inspired by the aromatization-driven C-C bond cleavage, here we demonstrate a ring-opening/aminocarbonylation cascade under copper catalysis, in which the formation of a stable γ-lactam or succinimide skeleton reverses the selectivity of C-C cleavage. Remarkably, the photo and thermal assistance is not required when the succinimide skeleton is formed during the ring opening process. DFT calculations revealed that this unexpected ring-opening process is thermodynamically and kinetically favourable.
基金The National Key Research and Development Program of Ministry of Science and Technology(No.2022YFA1504602)Natural Science Foundation of Jiangsu Province(No.BK20211094)National Natural Science Foundation of China(No.22302214,21972152,U22B20137).
文摘Carbonylation reactions,crucial for carbonyl group incorporation,struggle with the inherent complexity of achieving selective mono-or double-carbonylation on single substrates,often due to competing reaction pathways.Herein,our study introduces a strategy employing palladium amides,harnessing their unique reactivity control,to direct the selective carbonylation of amines for the targeted synthesis of urea and oxamide derivatives.The palladium amide structure was elucidated using single-crystal X-ray diffraction.Controlled experiments and cyclic voltammetry studies further elucidate that the oxidation of palladium amide or its insertion into a carbonyl group diverges into distinct pathways.By employing sodium percarbonate as an eco-friendly oxidant and base,we have successfully constructed a switchable carbonylation system co-catalyzed by palladium and iodide under room temperature.The utilizing strategy in this study not only facilitates effective control over reaction selectivity but also mitigates the risk of explosions,a critical safety concern in traditional carbonylation methods.
