The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodol...The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodology to achieve oxy-, thio-, and seleno-trifluoromethylation remains elusive yet highly desirable. In this study, we report a triarylamine-catalyzed three-component vicinal chalcogen-trifluoromethylation of alkenes under blue light irradiation without the need of transition metal catalyst. This reaction is broadly applicable to oxy, thio, and seleno nucleophiles, facilitating modular access to a diverse array of β-trifluoromethyl alcohols, ethers, thioethers, thiocyanates, and selenocyanates with good yields and predictable regioselectivities (61 examples). Additionally, we demonstrate its application in the late-stage modification of natural products and pharmaceutical compounds. Preliminary mechanistic studies suggest that a catalytic electron donor-acceptor (EDA) complex between triarylamine and the Umemoto reagent is key to enabling the radical/polar crossover process.展开更多
The direct difunctionalization of alkenes serves as one of the most straightforward strategies toward complex nitrogen-containing compounds.The existing approach is extensively promoted by using C/Xcentered radicals a...The direct difunctionalization of alkenes serves as one of the most straightforward strategies toward complex nitrogen-containing compounds.The existing approach is extensively promoted by using C/Xcentered radicals and N-nucleophiles to conduct 1,2-difunctional amination/azolization of alkenes.In contrast,2,1-difunctional amination/azolization of alkenes by using nitrogen-centered radicals(NCRs) and nucleophiles still remains rarely underexplored.It is possibly due to the highly active electron properties of NCRs and the relatively poor nucleophilicity of aromatic NCRs to be trapped by arylalkenes.Herein,we demonstrate an unprecedented 2,1-hydroxazolization reactions of arylalkenes through electrochemically enabled addition of NCRs from azoles and nucleophiles(NuH) in high yields and with high regioselectivity.This conversion is characterized by the fact that neither metal catalysts nor external chemical oxidants are required.This electrochemical oxidation synthesis method can also be applied for a broad range of NuH including pyridine hydrofluoride,ammonia,water,alcohols,and acids which enables the formation of C-N and C-X(X=F/N/O) bonds in one-pot fashion to furnish efficient fluoroamination,diamination and oxoamination of alkenes.展开更多
The hydroformylation of olefins,known as the"oxo reaction",involves the use of syngas(CO/H_(2))to produce aldehyde with an additional carbon atom.However,side reactions such as the isomerization or hydrogena...The hydroformylation of olefins,known as the"oxo reaction",involves the use of syngas(CO/H_(2))to produce aldehyde with an additional carbon atom.However,side reactions such as the isomerization or hydrogenation of olefins often result in unexpected products and other by-products.Recent efforts in developing efficient ligands represent the most effective approach to addressing these challenges.In this study,we described a Bis-OPNN phosphorus ligand facilitated Rh-catalyzed hydroformylation with a high degree of linear selectivity across various olefins.Under mild conditions,a broad range of olefins were efficiently converted into linear aldehydes with high yields and excellent regioselectivity.The protocol also showed impressive functional group tolerance and was successfully applied to modify drugs and natural products,including the total synthesis of(±)-crispine A.Preliminary mechanistic studies revealed that this Bis-OPNN phosphorus ligand anchoring the rhodium catalyst is crucial for controlling the linear selectivity.展开更多
Herein,we describe a nickel-catalyzed reductive decarboxylative difluoromethylation reaction of alkenes using inexpensive and easy-to-handle difluoroacetic anhydride(DFAA)/pyridine N-oxide reagent system.A variety of ...Herein,we describe a nickel-catalyzed reductive decarboxylative difluoromethylation reaction of alkenes using inexpensive and easy-to-handle difluoroacetic anhydride(DFAA)/pyridine N-oxide reagent system.A variety of C(sp^(3))-CF_(2)H containing compounds were prepared through a hydrodifluoromethylation process.Besides,various gem–difluoroalkenes bearing CF_(2)H group were synthesized via defluorinative reductive cross-coupling process from trifluoromethyl-substituted alkenes using this new reaction system.Difluoroacetic anhydride has been then extended to other common alkyl anhydrides,and the corresponding hydroalkylation and defluoroalkylation processes have been successfully achieved.This method features broad substrate scope,good functional group tolerance as well as high efficiency.展开更多
Catalytic electron donor-acceptor(EDA) complex photochemistry has recently emerged as a popular and sustainable alternative to photoredox synthetic methods. Yet, the catalytic EDA strategy is still in its infancy for ...Catalytic electron donor-acceptor(EDA) complex photochemistry has recently emerged as a popular and sustainable alternative to photoredox synthetic methods. Yet, the catalytic EDA strategy is still in its infancy for organic synthesis due to the challenges of designing novel catalytic paradigm and expanding the substrate and reaction scope. Here, we disclose a catalytic EDA/Cu cooperative strategy by employing Na I as a catalytic donor for copper-catalyzed radical asymmetric carbocyanation. A diverse range of synthetically useful chiral benzyl nitriles are produced with high enantioselectivities. This synergetic EDA/copper catalysis enables the decarboxylative cyanation without request of any photoredox catalysts, further expanding the synthetic potential of catalytic EDA chemistry in organic synthesis.展开更多
Here we present a highly efficient protocol utilizing nickel-hydride hydrogen atom transfer catalysis for the regio-and enantioselective hydrofluorination of internal alkenes.This method efficiently assembles a wide a...Here we present a highly efficient protocol utilizing nickel-hydride hydrogen atom transfer catalysis for the regio-and enantioselective hydrofluorination of internal alkenes.This method efficiently assembles a wide array of enantioenrichedβ-fluoro amides with excellent regio-and enantioselectivity from internal unactivated alkenes.Mechanistic investigations suggest that this transformation proceeds via a NiHhydrogen atom transfer to alkene,followed by a stereoselective fluorine atom transfer process.The weak coordination effect of the tethered amide group is identified as a crucial factor governing the observed regio-and enantioselectivity.展开更多
The accompanied forge of C(sp^(3))–S and C(sp^(3))–C(sp^(3))bonds across alkene frameworks serves as a potent strategy to construct biologically important compounds.Here,we report a metal-free,photochemically mediat...The accompanied forge of C(sp^(3))–S and C(sp^(3))–C(sp^(3))bonds across alkene frameworks serves as a potent strategy to construct biologically important compounds.Here,we report a metal-free,photochemically mediated fluoroalkyl-mono/disulfuration of unactivated alkenes with high efficiency and high selectivity.A wide range of terminal and internal alkenes are good coupling partners,affording the expected products in moderate to good yields(>90 examples).The exceedingly mild reaction conditions,exceptional functional group tolerance,broad substrate scope,and the potential for late-stage modifications of pharmaceutical molecules highlight the utility of this method in the preparation of privileged motifs from readily available disulfides,tetrasulfides,and diselenides.Mechanistic studies suggest that a secondary alkyl radical intermediate undergoes efficient homolytic substitution with disulfides,facilitating the modular synthesis of a diverse array of unsymmetrical thioethers.展开更多
An efficient and E-selective monoisomerization of 1-alkenes is developed with a bis(phosphine)-based PCP-type Co complex as the catalyst.The protocol provides an atom-economical approach to trans-2-alkenes with high r...An efficient and E-selective monoisomerization of 1-alkenes is developed with a bis(phosphine)-based PCP-type Co complex as the catalyst.The protocol provides an atom-economical approach to trans-2-alkenes with high regio-and stereoselectivity,featuring mild conditions and wide substrate scope.Mechanistic investigation supports a cobalt-hydride pathway involving reversible alkene insertion/β-H elimination,and the step ofβ-H elimination at the allylic position is likely the rate-determining step.展开更多
β-Amino sulfides hold significant biological importance,motivating the development of several methods for sulfenylamination of alkenes.However,these methods often involve a three-component system with limited alkene ...β-Amino sulfides hold significant biological importance,motivating the development of several methods for sulfenylamination of alkenes.However,these methods often involve a three-component system with limited alkene substrate range.In this study,we present a pioneering two-component approach utilizing readily accessible sulfenamides as efficient difunctionalization reagents.Key to its success is the careful selection of a suitable photosensitizer,which enables precise modulation of sulfenamides by promoting unprecedented energy transfer rather than traditional single-electron oxidation.This novel strategy leads to the concurrent formation of N-and S-radical species,ensuring high regioselectivity for both electronneutral and electron-deficient alkenes.As a result,a wide range of valuableβ-amino sulfides,including those with congested amine groups,can be readily synthesized.These findings highlight the potential of this method for the efficient synthesis of diverse functionalizedβ-amino sulfides.展开更多
A highly site-selective intermolecular trifluoromethylimination of activated and unactivated olefins was reported under transition-metal-and photosensitizer-free conditions.This newly developed strategy provides strai...A highly site-selective intermolecular trifluoromethylimination of activated and unactivated olefins was reported under transition-metal-and photosensitizer-free conditions.This newly developed strategy provides straightforward and efficient access to diverse value-added vicinal trifluoromethyl amines without resorting to the pre-functionalized reagents.Mechanistic experiments demonstrate that the approach proceeded through CF_(3)and iminyl two-radicals process,which were generated directly from commercially available benzophenone imine in a novel electron-donor mode via a SET process activated by the bifunctional hypervalent iodine reagents.The synthetic potential of the protocols was further showcased via the condensation/amination sequential cascade,and transformations to accessβ-CF_(3)primary amines.展开更多
A photoredox-catalyzed cascade carbon/carboxylation of activated alkenes with malonates acetals and CO_(2) has been achieved,leading to a range of functionalized 1,1,3-tricarboxylates in good efficiency under mild rea...A photoredox-catalyzed cascade carbon/carboxylation of activated alkenes with malonates acetals and CO_(2) has been achieved,leading to a range of functionalized 1,1,3-tricarboxylates in good efficiency under mild reaction conditions.This reaction provides a facile and sustainable method for the synthesis of tricarboxylates by using CO_(2) as the carboxylic source.展开更多
The hydrothiolations of alkynes/alkenes with thiols is an atom-economic and thus attractive method for the constructions of C‒S bonds.Here Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposites with varied Ir_(2)S_(3)loadings were o...The hydrothiolations of alkynes/alkenes with thiols is an atom-economic and thus attractive method for the constructions of C‒S bonds.Here Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposites with varied Ir_(2)S_(3)loadings were obtained by one-pot solvothermal method from ZnCl_(2),InCl_(3)and thioacetamide with IrCl_(3).The loading of Ir_(2)S_(3)on the surface of ZnIn_(2)S_(4)promoted the hydrothiolations of alkenes and alkynes,with an optimum performance observed over 0.5 mol%Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposite.Based on the studies on the performance of several other cocatalysts(MoS2,NiS and Pd)loaded ZnIn_(2)S_(4)and the EIS analyses,it was proposed that the superior performance over Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposite can be ascribed to an improved efficiency on the photogeneration of the thiyl radicals by loading Ir_(2)S_(3)as well as its inactivity for photocatalytic hydrogen evolution,a side reaction in the light initiated hydrothiolation reaction over ZnIn_(2)S_(4).This study not only demonstrates an efficient and green strategy to synthesize thiolated products under visible light based on semiconductor photocatalysis,but also provides some guidances for the design and development of photocatalytic systems for light induced organic syntheses.展开更多
The dibromination of alkenes and alkynes with bromosuccinimide and sodium bromide catalyzed by FeBr_3 under mild conditions has been developed.The trans-dibromo compounds were exclusively obtained with excellent yields.
The electrooxidative[3+2]annulation of amidines with 2-arylideneindane-1,3-diones or 4-alkylidene pyrazolones is reported using NaI as a redox catalyst and electrolyte under constant current electrolysis in an undivid...The electrooxidative[3+2]annulation of amidines with 2-arylideneindane-1,3-diones or 4-alkylidene pyrazolones is reported using NaI as a redox catalyst and electrolyte under constant current electrolysis in an undivided cell.The current strategy features excellent functional group tolerance,simple operation,and mild conditions,thus providing an environmentally benign and efficient access to spiroimidazolines in moderate to good yields.展开更多
Carbon-carbon double bond functional groups are often protected through a popular bromination/debromination method because of their reactivity. An ultrasonic-enhanced stereoselective debromination of vic-dibromides wi...Carbon-carbon double bond functional groups are often protected through a popular bromination/debromination method because of their reactivity. An ultrasonic-enhanced stereoselective debromination of vic-dibromides with metallic zinc powder in aqueous media has been developed, which generates E-alkenes with excellent yields. The reactivity of vic-dibromides decreases in the order of 1,2-dibromo-1,2-diphenylethane>1,2-dibromo-1-phenylethane>1,2-dibromo-1,2-dialkylethane.展开更多
Photoredox-catalyzed hydrodifluoromethylation of alkenes has become an effective method to introduce difluoromethyl group into organic molecules.As the reported methods involve either photocatalysts or superstoichiome...Photoredox-catalyzed hydrodifluoromethylation of alkenes has become an effective method to introduce difluoromethyl group into organic molecules.As the reported methods involve either photocatalysts or superstoichiometric amounts of additives,we herein describe a simple alternative without using photocatalyst or additive for the hydrodifluoromethylation of alkenes,through photoactivation of difluoromethyltriphenylphosphonium iodide salt.Mechanistic studies shed light on how the transformation takes place.展开更多
A nickel-catalyzed direct hydromonofluoromethylation of unactivated olefins with industrial raw fluoroiodomethane is developed,furnishing various primary alkyl fluorides in a step-economic manner.The key factor to suc...A nickel-catalyzed direct hydromonofluoromethylation of unactivated olefins with industrial raw fluoroiodomethane is developed,furnishing various primary alkyl fluorides in a step-economic manner.The key factor to success is the use of pyridine-oxazoline as ligand and(MeO)_(2)MeSiH as the hydrogen source.This transformation demonstrates high efficiency,mild conditions,good functional-group compatibility and great potential in the drug discovery.展开更多
Difunctionalization of alkenes have developed into an important type of reactions for rapidly and efficiently assemble complex molecules.While extensive advancements have been achieved by the assistance of transition ...Difunctionalization of alkenes have developed into an important type of reactions for rapidly and efficiently assemble complex molecules.While extensive advancements have been achieved by the assistance of transition metal catalysis,the employment of cheap,abundant aryl chlorides as coupling partner is still a challenging task in this field.Herein,we report our first achievement in 1,1-difunctionalization of alkenes with aryl chlorides as coupling partners.The success is predominantly ascribed to the judicious selection of 1,2-diamine ligand.This study provides an efficient protocol for the synthesis of secondary benzyl boronates from easily accessible feedstock chemicals.Furthermore,the distinguished features of this method include excellent 1,1-regio-and chemoselectivity,good functional group tolerance and easily-operational catalytic reaction conditions.展开更多
The addition reactions of alkenes and alkynes to the H-terminated GaN （0001） surface with a Ga dangling-bond have been studied employing periodic density functional theory （PDFT） calculations. Detailed information...The addition reactions of alkenes and alkynes to the H-terminated GaN （0001） surface with a Ga dangling-bond have been studied employing periodic density functional theory （PDFT） calculations. Detailed information on the reaction pathways of these alkenes and alkynes with H-GaN （0001） surface is provided, which indicates that the reactions contain two steps separated by the metastable intermediates： elementary addition reaction and H-abstraction process. From the energy curves, the reactions are clearly viable in the cases of ethene, styrene and phenylacetylene; while for ethyne, the H-abstraction barrier is higher than the desorption barrier of the intermediate, so the adsorbed C2H2 in intermediate is more likely to be desorbed back into the gas phase than to form a stable adsorbed species. Furthermore, it is obvious that for either alkenes or alkynes, the systems substituted by phenyl have more stable intermediates because π conjugation could improve their stabilities.展开更多
A Zn/NH4Cl system was exploited at room temperature to promote the Michael addition reaction of various primary and secondary amines with α,β-unsaturated esters,nitriles,amides,and ketones to give the corresponding ...A Zn/NH4Cl system was exploited at room temperature to promote the Michael addition reaction of various primary and secondary amines with α,β-unsaturated esters,nitriles,amides,and ketones to give the corresponding saturated amines under the mild condition in high yield.展开更多
基金the financial support provided by the National Natural Science Foundation of China(22361142832,92156025,22271212)the Science and Technology Project of Hebei Education Department Foundation(BJ2025192)We would like to thank Dr.Guosheng Ding,Dr.Kongying Zhu,and Dr.Xiaojuan Deng at the Analysis and Testing Center of Tianjin University for their assistance with NMR testing and analysis.
文摘The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodology to achieve oxy-, thio-, and seleno-trifluoromethylation remains elusive yet highly desirable. In this study, we report a triarylamine-catalyzed three-component vicinal chalcogen-trifluoromethylation of alkenes under blue light irradiation without the need of transition metal catalyst. This reaction is broadly applicable to oxy, thio, and seleno nucleophiles, facilitating modular access to a diverse array of β-trifluoromethyl alcohols, ethers, thioethers, thiocyanates, and selenocyanates with good yields and predictable regioselectivities (61 examples). Additionally, we demonstrate its application in the late-stage modification of natural products and pharmaceutical compounds. Preliminary mechanistic studies suggest that a catalytic electron donor-acceptor (EDA) complex between triarylamine and the Umemoto reagent is key to enabling the radical/polar crossover process.
基金the National Science Foundation of China(No.22071058)the Fundamental Research Funds for the Central Universities for financial support。
文摘The direct difunctionalization of alkenes serves as one of the most straightforward strategies toward complex nitrogen-containing compounds.The existing approach is extensively promoted by using C/Xcentered radicals and N-nucleophiles to conduct 1,2-difunctional amination/azolization of alkenes.In contrast,2,1-difunctional amination/azolization of alkenes by using nitrogen-centered radicals(NCRs) and nucleophiles still remains rarely underexplored.It is possibly due to the highly active electron properties of NCRs and the relatively poor nucleophilicity of aromatic NCRs to be trapped by arylalkenes.Herein,we demonstrate an unprecedented 2,1-hydroxazolization reactions of arylalkenes through electrochemically enabled addition of NCRs from azoles and nucleophiles(NuH) in high yields and with high regioselectivity.This conversion is characterized by the fact that neither metal catalysts nor external chemical oxidants are required.This electrochemical oxidation synthesis method can also be applied for a broad range of NuH including pyridine hydrofluoride,ammonia,water,alcohols,and acids which enables the formation of C-N and C-X(X=F/N/O) bonds in one-pot fashion to furnish efficient fluoroamination,diamination and oxoamination of alkenes.
基金financial support from the National Key Research and Development Program of China(No.2021YFF0600704).
文摘The hydroformylation of olefins,known as the"oxo reaction",involves the use of syngas(CO/H_(2))to produce aldehyde with an additional carbon atom.However,side reactions such as the isomerization or hydrogenation of olefins often result in unexpected products and other by-products.Recent efforts in developing efficient ligands represent the most effective approach to addressing these challenges.In this study,we described a Bis-OPNN phosphorus ligand facilitated Rh-catalyzed hydroformylation with a high degree of linear selectivity across various olefins.Under mild conditions,a broad range of olefins were efficiently converted into linear aldehydes with high yields and excellent regioselectivity.The protocol also showed impressive functional group tolerance and was successfully applied to modify drugs and natural products,including the total synthesis of(±)-crispine A.Preliminary mechanistic studies revealed that this Bis-OPNN phosphorus ligand anchoring the rhodium catalyst is crucial for controlling the linear selectivity.
基金financial support from the National Natural Science Foundation of China(NSFC,No.21877067)Tsinghua-Peking Centre for Life Science。
文摘Herein,we describe a nickel-catalyzed reductive decarboxylative difluoromethylation reaction of alkenes using inexpensive and easy-to-handle difluoroacetic anhydride(DFAA)/pyridine N-oxide reagent system.A variety of C(sp^(3))-CF_(2)H containing compounds were prepared through a hydrodifluoromethylation process.Besides,various gem–difluoroalkenes bearing CF_(2)H group were synthesized via defluorinative reductive cross-coupling process from trifluoromethyl-substituted alkenes using this new reaction system.Difluoroacetic anhydride has been then extended to other common alkyl anhydrides,and the corresponding hydroalkylation and defluoroalkylation processes have been successfully achieved.This method features broad substrate scope,good functional group tolerance as well as high efficiency.
基金the National Natural Science Foundation of China (No. 22201087) for the financial support。
文摘Catalytic electron donor-acceptor(EDA) complex photochemistry has recently emerged as a popular and sustainable alternative to photoredox synthetic methods. Yet, the catalytic EDA strategy is still in its infancy for organic synthesis due to the challenges of designing novel catalytic paradigm and expanding the substrate and reaction scope. Here, we disclose a catalytic EDA/Cu cooperative strategy by employing Na I as a catalytic donor for copper-catalyzed radical asymmetric carbocyanation. A diverse range of synthetically useful chiral benzyl nitriles are produced with high enantioselectivities. This synergetic EDA/copper catalysis enables the decarboxylative cyanation without request of any photoredox catalysts, further expanding the synthetic potential of catalytic EDA chemistry in organic synthesis.
基金This research was made possible as a result of a generous grant from the Fundamental Research Funds for the Central Universities(Nos.2232024Y-01,2232024A-03)the National Science Fund for Excellent Young Scholars(No.22122101).
文摘Here we present a highly efficient protocol utilizing nickel-hydride hydrogen atom transfer catalysis for the regio-and enantioselective hydrofluorination of internal alkenes.This method efficiently assembles a wide array of enantioenrichedβ-fluoro amides with excellent regio-and enantioselectivity from internal unactivated alkenes.Mechanistic investigations suggest that this transformation proceeds via a NiHhydrogen atom transfer to alkene,followed by a stereoselective fluorine atom transfer process.The weak coordination effect of the tethered amide group is identified as a crucial factor governing the observed regio-and enantioselectivity.
文摘The accompanied forge of C(sp^(3))–S and C(sp^(3))–C(sp^(3))bonds across alkene frameworks serves as a potent strategy to construct biologically important compounds.Here,we report a metal-free,photochemically mediated fluoroalkyl-mono/disulfuration of unactivated alkenes with high efficiency and high selectivity.A wide range of terminal and internal alkenes are good coupling partners,affording the expected products in moderate to good yields(>90 examples).The exceedingly mild reaction conditions,exceptional functional group tolerance,broad substrate scope,and the potential for late-stage modifications of pharmaceutical molecules highlight the utility of this method in the preparation of privileged motifs from readily available disulfides,tetrasulfides,and diselenides.Mechanistic studies suggest that a secondary alkyl radical intermediate undergoes efficient homolytic substitution with disulfides,facilitating the modular synthesis of a diverse array of unsymmetrical thioethers.
文摘An efficient and E-selective monoisomerization of 1-alkenes is developed with a bis(phosphine)-based PCP-type Co complex as the catalyst.The protocol provides an atom-economical approach to trans-2-alkenes with high regio-and stereoselectivity,featuring mild conditions and wide substrate scope.Mechanistic investigation supports a cobalt-hydride pathway involving reversible alkene insertion/β-H elimination,and the step ofβ-H elimination at the allylic position is likely the rate-determining step.
基金financial support from the National Natural Science Foundation of China(Nos.22171072,21925103,and22301061)。
文摘β-Amino sulfides hold significant biological importance,motivating the development of several methods for sulfenylamination of alkenes.However,these methods often involve a three-component system with limited alkene substrate range.In this study,we present a pioneering two-component approach utilizing readily accessible sulfenamides as efficient difunctionalization reagents.Key to its success is the careful selection of a suitable photosensitizer,which enables precise modulation of sulfenamides by promoting unprecedented energy transfer rather than traditional single-electron oxidation.This novel strategy leads to the concurrent formation of N-and S-radical species,ensuring high regioselectivity for both electronneutral and electron-deficient alkenes.As a result,a wide range of valuableβ-amino sulfides,including those with congested amine groups,can be readily synthesized.These findings highlight the potential of this method for the efficient synthesis of diverse functionalizedβ-amino sulfides.
基金Financial support from the National Natural Science Foundation of China(Nos.22201239,22205192 and 22271244)the Hunan Provincial Natural Science Foundation of China(No.2022JJ40429)+2 种基金the Scientific Research Fund of Hunan Provincial Education Department(No.21B0130)the Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University(No.2022C02)the Process Intensification&Green Chemical Engineering Innovation Team Project of Hunan Province。
文摘A highly site-selective intermolecular trifluoromethylimination of activated and unactivated olefins was reported under transition-metal-and photosensitizer-free conditions.This newly developed strategy provides straightforward and efficient access to diverse value-added vicinal trifluoromethyl amines without resorting to the pre-functionalized reagents.Mechanistic experiments demonstrate that the approach proceeded through CF_(3)and iminyl two-radicals process,which were generated directly from commercially available benzophenone imine in a novel electron-donor mode via a SET process activated by the bifunctional hypervalent iodine reagents.The synthetic potential of the protocols was further showcased via the condensation/amination sequential cascade,and transformations to accessβ-CF_(3)primary amines.
文摘A photoredox-catalyzed cascade carbon/carboxylation of activated alkenes with malonates acetals and CO_(2) has been achieved,leading to a range of functionalized 1,1,3-tricarboxylates in good efficiency under mild reaction conditions.This reaction provides a facile and sustainable method for the synthesis of tricarboxylates by using CO_(2) as the carboxylic source.
文摘The hydrothiolations of alkynes/alkenes with thiols is an atom-economic and thus attractive method for the constructions of C‒S bonds.Here Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposites with varied Ir_(2)S_(3)loadings were obtained by one-pot solvothermal method from ZnCl_(2),InCl_(3)and thioacetamide with IrCl_(3).The loading of Ir_(2)S_(3)on the surface of ZnIn_(2)S_(4)promoted the hydrothiolations of alkenes and alkynes,with an optimum performance observed over 0.5 mol%Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposite.Based on the studies on the performance of several other cocatalysts(MoS2,NiS and Pd)loaded ZnIn_(2)S_(4)and the EIS analyses,it was proposed that the superior performance over Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposite can be ascribed to an improved efficiency on the photogeneration of the thiyl radicals by loading Ir_(2)S_(3)as well as its inactivity for photocatalytic hydrogen evolution,a side reaction in the light initiated hydrothiolation reaction over ZnIn_(2)S_(4).This study not only demonstrates an efficient and green strategy to synthesize thiolated products under visible light based on semiconductor photocatalysis,but also provides some guidances for the design and development of photocatalytic systems for light induced organic syntheses.
基金the financial support by Lishui University Opening Foundation for advanced talents
文摘The dibromination of alkenes and alkynes with bromosuccinimide and sodium bromide catalyzed by FeBr_3 under mild conditions has been developed.The trans-dibromo compounds were exclusively obtained with excellent yields.
基金the National Natural Science Foundation of China (No. 22078150)the Natural Science Foundation of Jiangsu Province, Frontier Project (No. BK20212003)
文摘The electrooxidative[3+2]annulation of amidines with 2-arylideneindane-1,3-diones or 4-alkylidene pyrazolones is reported using NaI as a redox catalyst and electrolyte under constant current electrolysis in an undivided cell.The current strategy features excellent functional group tolerance,simple operation,and mild conditions,thus providing an environmentally benign and efficient access to spiroimidazolines in moderate to good yields.
基金Supported by the National Natural Science Foundation of China(No.2 0 372 0 2 4 2 0 172 0 18) +2 种基金the Excellent ScientistFoundation of Anhui ProvinceChina(No.2 0 0 10 4 0 ) the Natural Science Foundation of the Educational Departm entof AnhuiProvince
文摘Carbon-carbon double bond functional groups are often protected through a popular bromination/debromination method because of their reactivity. An ultrasonic-enhanced stereoselective debromination of vic-dibromides with metallic zinc powder in aqueous media has been developed, which generates E-alkenes with excellent yields. The reactivity of vic-dibromides decreases in the order of 1,2-dibromo-1,2-diphenylethane>1,2-dibromo-1-phenylethane>1,2-dibromo-1,2-dialkylethane.
基金financial support from the National Natural Science Foundation of China(Nos.22001248 and 22173103)the Fundamental Research Funds for the Central Universities and the University of the Chinese Academy of Sciences。
文摘Photoredox-catalyzed hydrodifluoromethylation of alkenes has become an effective method to introduce difluoromethyl group into organic molecules.As the reported methods involve either photocatalysts or superstoichiometric amounts of additives,we herein describe a simple alternative without using photocatalyst or additive for the hydrodifluoromethylation of alkenes,through photoactivation of difluoromethyltriphenylphosphonium iodide salt.Mechanistic studies shed light on how the transformation takes place.
基金National Natural Science Foundation of China(No.21971228)for financial support。
文摘A nickel-catalyzed direct hydromonofluoromethylation of unactivated olefins with industrial raw fluoroiodomethane is developed,furnishing various primary alkyl fluorides in a step-economic manner.The key factor to success is the use of pyridine-oxazoline as ligand and(MeO)_(2)MeSiH as the hydrogen source.This transformation demonstrates high efficiency,mild conditions,good functional-group compatibility and great potential in the drug discovery.
基金supported by grants from the National Natural Science Foundation of China(No.22122107)the Fundamental Research Funds for Central Universities(No.2042021kf0190).
文摘Difunctionalization of alkenes have developed into an important type of reactions for rapidly and efficiently assemble complex molecules.While extensive advancements have been achieved by the assistance of transition metal catalysis,the employment of cheap,abundant aryl chlorides as coupling partner is still a challenging task in this field.Herein,we report our first achievement in 1,1-difunctionalization of alkenes with aryl chlorides as coupling partners.The success is predominantly ascribed to the judicious selection of 1,2-diamine ligand.This study provides an efficient protocol for the synthesis of secondary benzyl boronates from easily accessible feedstock chemicals.Furthermore,the distinguished features of this method include excellent 1,1-regio-and chemoselectivity,good functional group tolerance and easily-operational catalytic reaction conditions.
基金Supported by the National Natural Science Foundation of China (No 20673019)
文摘The addition reactions of alkenes and alkynes to the H-terminated GaN （0001） surface with a Ga dangling-bond have been studied employing periodic density functional theory （PDFT） calculations. Detailed information on the reaction pathways of these alkenes and alkynes with H-GaN （0001） surface is provided, which indicates that the reactions contain two steps separated by the metastable intermediates： elementary addition reaction and H-abstraction process. From the energy curves, the reactions are clearly viable in the cases of ethene, styrene and phenylacetylene; while for ethyne, the H-abstraction barrier is higher than the desorption barrier of the intermediate, so the adsorbed C2H2 in intermediate is more likely to be desorbed back into the gas phase than to form a stable adsorbed species. Furthermore, it is obvious that for either alkenes or alkynes, the systems substituted by phenyl have more stable intermediates because π conjugation could improve their stabilities.
基金Supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education,China
文摘A Zn/NH4Cl system was exploited at room temperature to promote the Michael addition reaction of various primary and secondary amines with α,β-unsaturated esters,nitriles,amides,and ketones to give the corresponding saturated amines under the mild condition in high yield.
