Photoelectrocatalysis(PEC)is extensively applied in diverse redox reactions.However,the traditional oxygen evolution reaction(OER)occurring at the(photo)anode is hindered by high thermodynamic demands and sluggish kin...Photoelectrocatalysis(PEC)is extensively applied in diverse redox reactions.However,the traditional oxygen evolution reaction(OER)occurring at the(photo)anode is hindered by high thermodynamic demands and sluggish kinetics,resulting in excessive energy consumption and limited economic value of the O2 produced,thereby impeding the practical application of PEC reactions.To overcome these limitations,advanced anodic-cathodic coupling systems,as an emerging energy conversion technology,have garnered significant research interest.These systems substitute OER with lower potential,valuable oxidation reactions,significantly enhancing energy conversion efficiency,yielding high-value chemicals,while reducing energy consumption and environmental pollution.More importantly,by designing and optimizing photoelectrodes to generate sufficient photovoltage under illumination,meeting the thermodynamic and kinetic potential requirements of the reactions,and by tuning the voltage to match the current densities of the cathode and anode,coupling reactions can be achieved under bias-free conditions.In this review,we provide an overview of the mechanisms of PEC coupling reactions and summarize photoelectrode catalysts along with their synthesis methods.We further explore advanced catalyst modification strategies and highlight the latest development in advanced PEC coupling systems,including photocathodic CO_(2)reduction,nitrate reduction,oxygen reduction,enzyme activation,coupled with photoanodic organic oxidation,biomass oxidation,and pollutant degradation.Additionally,advanced in situ characterization techniques for elucidating reaction mechanisms are discussed.Finally,we propose the challenges in catalyst design,reaction systems,and large-scale applications,while offering future perspectives for PEC coupling system.This work underscores the tremendous potential of PEC coupling systems in energy conversion and environmental remediation,and provides valuable insights for the future design of such coupling systems.展开更多
By using a newly developed 4-hydroxy picolinohydrazide as the ligand,Cu-catalyzed coupling of(hetero)aryl chlorides with sodium aryl sulfonates proceeded smoothly at 130℃to give a series of biarylsulfones in 53%~96%y...By using a newly developed 4-hydroxy picolinohydrazide as the ligand,Cu-catalyzed coupling of(hetero)aryl chlorides with sodium aryl sulfonates proceeded smoothly at 130℃to give a series of biarylsulfones in 53%~96%yields.This represents the first metal-catalyzed coupling reaction of(hetero)aryl chlorides with sodium aryl sulfonates.Aryl and heteroaryl chlorides bearing either electron-donating or electron-withdrawing groups were applicable for this coupling reaction.展开更多
The system,Pd（OAc）_2/imidazolium salts（L_2）,was found as an efficient catalyst in the Heck coupling reaction of olefins with aryl halides and Suzuki reactions of various aryl halides with aryl boronic acids under ...The system,Pd（OAc）_2/imidazolium salts（L_2）,was found as an efficient catalyst in the Heck coupling reaction of olefins with aryl halides and Suzuki reactions of various aryl halides with aryl boronic acids under aerobic condition.This catalytic system demonstrates great tolerance to a wide range of groups on all substrates of aryl halides,alkenes and aryl boronic acids.展开更多
Polyanilines(PANIs) can be easily prepared from the available and cheap anilines via the oxidative polymerization reactions. Owing to the coordination of nitrogen in the material with metals, PANIs are widely used as ...Polyanilines(PANIs) can be easily prepared from the available and cheap anilines via the oxidative polymerization reactions. Owing to the coordination of nitrogen in the material with metals, PANIs are widely used as the support of nano metal catalysts. In comparison with inorganic supports, the nano metals on PANIs were firmly anchored via the coordination bond so that they are not easily to lose during the reaction process. Moreover, since PANIs are versatile materials and their chemical features can be adjusted by introducing functional groups onto the monomers, the catalytic activities of the prepared catalysts are tunable. During the past decade, PANIs-supported nano metal catalysts have been widely applied in a variety of coupling reactions. This review aims to summarize the recent advances and give a perspective.展开更多
CuI/ethylene diamine/K2CO3/dioxane is shown to be a useful system for the cross coupling reactions of various aryl iodides and bromides with aryl and alkyl alkynes. Compared to the conventional Sonogashira reactions, ...CuI/ethylene diamine/K2CO3/dioxane is shown to be a useful system for the cross coupling reactions of various aryl iodides and bromides with aryl and alkyl alkynes. Compared to the conventional Sonogashira reactions, the new procedure is free of palladium and phosphines.展开更多
To achieve the resource utilization of solid waste phosphogypsum(PG)and tackle the problem of utilizing potassium feldspar(PF),a coupled synergistic process between PG and PF is proposed in this paper.The study invest...To achieve the resource utilization of solid waste phosphogypsum(PG)and tackle the problem of utilizing potassium feldspar(PF),a coupled synergistic process between PG and PF is proposed in this paper.The study investigates the features of P and F in PG,and explores the decomposition of PF using hydrofluoric acid(HF)in the sulfuric acid system for K leaching and leaching of P and F in PG.The impact factors such as sulfuric acid concentration,reaction temperature,reaction time,material ratio(PG/PF),liquid–solid ratio,PF particle size,and PF calcination temperature on the leaching of P and K is systematically investigated in this paper.The results show that under optimal conditions,the leaching rate of K and P reach more than 93%and 96%,respectively.Kinetics study using shrinking core model(SCM)indicates two significant stages with internal diffusion predominantly controlling the leaching of K.The apparent activation energies of these two stages are 11.92 kJ·mol^(-1)and 11.55 kJ·mol^(-1),respectively.展开更多
Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)holds great promise in green energy conversion and storage.However,for current CO_(2) electrolyzers that rely on the oxygen evolution reaction,a large portion of the...Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)holds great promise in green energy conversion and storage.However,for current CO_(2) electrolyzers that rely on the oxygen evolution reaction,a large portion of the input energy is"wasted"at the anode due to the high overpotential requirement and the recovery of low-value oxygen.To make efficient use of the electricity during electrolysis,coupling CO_(2)RR with anodic alternatives that have low energy demands and/or profitable returns with high-value products is then promising.Herein,we review the latest advances in paired systems for simultaneous CO_(2) reduction and anode valorization.We start with the cases integrating CO_(2)RR with concurrent alternative oxidation,such as inorganic oxidation using chloride,sulfide,ammonia and urea,and organic oxidation using alcohols,aldehydes and primary amines.The paired systems that couple CO_(2)RR with on-site oxidative upgrading of CO_(2)-reduced chemicals are also introduced.The coupling mechanism,electrochemical performance and economic viability of these co-electrolysis systems are discussed.Thereby,we then point out the mismatch issues between the cathodic and anodic reactions regrading catalyst ability,electrolyte solution and reactant supply that will challenge the applications of these paired electrolysis systems.Opportunities to address these issues are further proposed,providing some guidance for future research.展开更多
Palladium(Pd)‐based catalysts are essential to drive high‐performance Suzuki coupling reactions,which are powerful tools for the synthesis of functional organic compounds.Herein,we developed a solution‐rapid‐annea...Palladium(Pd)‐based catalysts are essential to drive high‐performance Suzuki coupling reactions,which are powerful tools for the synthesis of functional organic compounds.Herein,we developed a solution‐rapid‐annealing process to stabilize nitrogen‐mesoporous carbon supported Pd single‐atom/cluster(Pd/NMC)material,which provided a catalyst with superior performance for Suzuki coupling reactions.In comparison with commercial palladium/carbon(Pd/C)catalysts,the Pd/NMC catalyst exhibited significantly boosted activity(100%selectivity and 95%yield)and excellent stability(almost no decay in activity after 10 reuse cycles)for the Suzuki coupling reactions of chlorobenzenes,together with superior yield and excellent selectivity in the fields of the board scope of the reactants.Moreover,our newly developed rapid annealing process of precursor solutions is applied as a generalized method to stabilize metal clusters(e.g.Pd,Pt,Ru),opening new possibilities in the construction of efficient highly dispersed metal atom and sub‐nanometer cluster catalysts with high performance.展开更多
Sm/TiCl4 system could well integrate the high reactivity of samarium（Ⅱ） and high deoxygenation capacity of low valent titanium within one system. In this paper, the intermolecular and intramolecular reductive coupl...Sm/TiCl4 system could well integrate the high reactivity of samarium（Ⅱ） and high deoxygenation capacity of low valent titanium within one system. In this paper, the intermolecular and intramolecular reductive coupling reactions of ketones with esters mediated by metallic samarium （Sm） and a catalytic amount of titanium tetrachloride （TiCl4） were successfully developed. A series of substituted ketones and cyclic β-keto-esters were prepared in moderate to good yields under reflux and neutral conditions.展开更多
Pinacol coupling reactions catalyzed by active zinc revealed high activity and extensive suitability. The efficiency of the reaction was improved apparently owing to decreasing reductive potential of zinc. In addition...Pinacol coupling reactions catalyzed by active zinc revealed high activity and extensive suitability. The efficiency of the reaction was improved apparently owing to decreasing reductive potential of zinc. In addition, the results indicated that the zinc activity has a direct relation to the coupling reactivity compared to untreated zinc or other general active zinc.展开更多
An efficient synthetic protocol for the 1,4-diaryl-1,4-dihydropyridines was developed via the domino four-component reaction of arylamine,acetylenedicarboxylate,aromatic aldehyde and ethyl acetoacetate.The reaction me...An efficient synthetic protocol for the 1,4-diaryl-1,4-dihydropyridines was developed via the domino four-component reaction of arylamine,acetylenedicarboxylate,aromatic aldehyde and ethyl acetoacetate.The reaction mechanism involves the formation of β-enamino ester and its sequential Michael addition to arylidene acetoacetate.展开更多
Due to the increasing demand for the sustainability of modern organic chemistry, the development of green and powerful methods for C-C and C-B bond formation is highly desired. Among them, the transition-metal-free co...Due to the increasing demand for the sustainability of modern organic chemistry, the development of green and powerful methods for C-C and C-B bond formation is highly desired. Among them, the transition-metal-free coupling reactions of gem–diborylalkanes emerge as one valuable tool for organic chemists in the last decade. The review covers selected representative examples. A comparison of these reactions with transition-metal-catalyzed reactions is provided. The recent example of α-boryl radical formation from gem–diborylalkanes is also briefly discussed.展开更多
The chemistry of acetaldehyde (CH3CHO) adsorbed on the anatase TiO2(001)-(1×4) surface has been investigated by temperature-programmed desorption (TPD) method. Our experimental results provide the direct evidence...The chemistry of acetaldehyde (CH3CHO) adsorbed on the anatase TiO2(001)-(1×4) surface has been investigated by temperature-programmed desorption (TPD) method. Our experimental results provide the direct evidence that the perfect lattice sites on the anatase TiO2(001)-(1×4) surface are quite inert for the reaction of CH3CHO, but the reduced defect sites on the surface are active for the thermally driven reductive carbon-carbon coupling reactions of CH3CHO to produce 2-butanone and butene. We propose that the coupling reactions of CH3CHO on the anatase TiO2(001)-(1×4) surface should undergo through the adsorption of paired CH3CHO molecules at the reduced defect sites, since the existing reduced Ti pairs provide the suitable adsorption sites.展开更多
Binaphthalene-core phosphepine compounds with axial chirality belong to an important class of organocatalysts and ligands used in catalytic asymmetric synthesis.However,the number and application of these compounds ha...Binaphthalene-core phosphepine compounds with axial chirality belong to an important class of organocatalysts and ligands used in catalytic asymmetric synthesis.However,the number and application of these compounds have been limited due to the lack of efficient synthetic methods currently available to researchers.Herein,a simple and efficient palladium-catalyzed C—P cross-coupling reaction of enantiopure(R)-1 with a variety of aryl and heteroaryl halides is reported.The reaction provides access to a series of chiral binaphthalene-core phosphepine compounds using Pd(OAc)2/dippf as a catalyst,which allows most products to be formed in moderate to high yields(40%~92%)with excellent ee values(90%~99%ee).展开更多
An efficient route to synthesize the heteroaryl-substituted 1,8-naphthyridine derivatives was described. Eight 2-heteroaryl- and 2,7-diheteroaryl-1,8-naphthyridine derivatives were obtained through palladium-catalyzed...An efficient route to synthesize the heteroaryl-substituted 1,8-naphthyridine derivatives was described. Eight 2-heteroaryl- and 2,7-diheteroaryl-1,8-naphthyridine derivatives were obtained through palladium-catalyzed C-N-coupling reactions of chloronaphthyridines with imidazole, benzimidazole, morpholine, 3,5-dimethylpyrazole, and phthalimide in moderate to good yields.展开更多
Dehydrogenation of ethylbenzene （EB） to styrene （ST） in the presence of CO2, in which EB dehydrogenation is coupled with the reverse water-gas shift （RWGS）, was investigated extensively through both theoretical ...Dehydrogenation of ethylbenzene （EB） to styrene （ST） in the presence of CO2, in which EB dehydrogenation is coupled with the reverse water-gas shift （RWGS）, was investigated extensively through both theoretical analysis and experimental characterization. The reaction coupling proved to be superior to the single dehydrogenation in several respects. Thermodynamic analysis suggests that equilibrium conversion of EB can be improved greatly by reaction coupling due to the simultaneous elimination of the hydrogen produced from dehydrogenation. Catalytic tests proved that iron and vanadium supported on activated carbon or Al2O3 with certain promoters are potential catalysts for this coupling process. The catalysts of iron and vanadium are different in the reaction mechanism, although ST yield is always associated with CO2 conversion over various catalysts. The two-step pathway plays an important role in the coupling process over Fe/Al2O3, while the one-step pathway dominates the reaction over V/Al2O3. Coke deposition and deep reduction of active components are the major causes of catalyst deactivation. CO2 can alleviate the catalyst deactivation effectively through preserving the active species at high valence in the coupling process, though it can not suppress the coke deposition.展开更多
Three types of ligands have been developed for copper-catalyzed Ullmann cross coupling reaction of bromaminic acid with amines in aqueous solution. Ligands with large steric hindrance and strong electron-donating capa...Three types of ligands have been developed for copper-catalyzed Ullmann cross coupling reaction of bromaminic acid with amines in aqueous solution. Ligands with large steric hindrance and strong electron-donating capacity were beneficial to the reaction. UV–Vis and CV analyses demonstrated that these ligands had strong coordination with copper(I), implying the effect of ligand coordination ability on the stability and catalytic activity of catalytic system.展开更多
Combining microwave radiation with photocatalytic systems is a promising method to inhibit photogenerated electron-hole recombination and enhance the photocatalytic reaction performance. In this study, we have designe...Combining microwave radiation with photocatalytic systems is a promising method to inhibit photogenerated electron-hole recombination and enhance the photocatalytic reaction performance. In this study, we have designed Pd/Pb TiO3 catalysts that can use both microwave fields and photocatalysis. Benefiting from the synergistic effect of microwave field and UV light, the Pb TiO3 crystals convert thermal energy into electrical energy via the pyroelectricity effect, generating positive and negative charges(q+ and q-), while Pd nanoparticles significantly improve the quantum efficiency of the photocatalytic process. The composite catalyst significantly enhances the reaction rate and selectivity of the model Suzuki coupling reaction performed with bromobenzene. Microwave fields can directly act on chemical systems, promoting or changing various chemical reactions in unique ways.展开更多
A convenient and efficient method for the preparation of α-substituted β-amino acids has been developed by reacting compound 2 with various boric acid/borate 3 through Suzuki coupling reaction,which gave multiple st...A convenient and efficient method for the preparation of α-substituted β-amino acids has been developed by reacting compound 2 with various boric acid/borate 3 through Suzuki coupling reaction,which gave multiple structure types of substituted Ni（II） complexes 4 in high yields.Hydrogenation and hydrolysis of complexes 4 led to the corresponding α-substituted β-amino acids.展开更多
An additive-free and environmentally friendly strategy has been realized for the construction of S-substituted isothioureas through visible-light-induced multicomponent reaction starting fromα-diazoesters,aryl isothi...An additive-free and environmentally friendly strategy has been realized for the construction of S-substituted isothioureas through visible-light-induced multicomponent reaction starting fromα-diazoesters,aryl isothiocyanates,amines and cyclic ethers.This methodology features simple operation,mild reaction conditions,favorable functional group tolerance,easily available starting materials and high efficiency.展开更多
文摘Photoelectrocatalysis(PEC)is extensively applied in diverse redox reactions.However,the traditional oxygen evolution reaction(OER)occurring at the(photo)anode is hindered by high thermodynamic demands and sluggish kinetics,resulting in excessive energy consumption and limited economic value of the O2 produced,thereby impeding the practical application of PEC reactions.To overcome these limitations,advanced anodic-cathodic coupling systems,as an emerging energy conversion technology,have garnered significant research interest.These systems substitute OER with lower potential,valuable oxidation reactions,significantly enhancing energy conversion efficiency,yielding high-value chemicals,while reducing energy consumption and environmental pollution.More importantly,by designing and optimizing photoelectrodes to generate sufficient photovoltage under illumination,meeting the thermodynamic and kinetic potential requirements of the reactions,and by tuning the voltage to match the current densities of the cathode and anode,coupling reactions can be achieved under bias-free conditions.In this review,we provide an overview of the mechanisms of PEC coupling reactions and summarize photoelectrode catalysts along with their synthesis methods.We further explore advanced catalyst modification strategies and highlight the latest development in advanced PEC coupling systems,including photocathodic CO_(2)reduction,nitrate reduction,oxygen reduction,enzyme activation,coupled with photoanodic organic oxidation,biomass oxidation,and pollutant degradation.Additionally,advanced in situ characterization techniques for elucidating reaction mechanisms are discussed.Finally,we propose the challenges in catalyst design,reaction systems,and large-scale applications,while offering future perspectives for PEC coupling system.This work underscores the tremendous potential of PEC coupling systems in energy conversion and environmental remediation,and provides valuable insights for the future design of such coupling systems.
文摘By using a newly developed 4-hydroxy picolinohydrazide as the ligand,Cu-catalyzed coupling of(hetero)aryl chlorides with sodium aryl sulfonates proceeded smoothly at 130℃to give a series of biarylsulfones in 53%~96%yields.This represents the first metal-catalyzed coupling reaction of(hetero)aryl chlorides with sodium aryl sulfonates.Aryl and heteroaryl chlorides bearing either electron-donating or electron-withdrawing groups were applicable for this coupling reaction.
基金the Research Council of University of Maragheh for financially support of this workM.B.thanks the Sharif University of Technology for funding of this work
文摘The system,Pd（OAc）_2/imidazolium salts（L_2）,was found as an efficient catalyst in the Heck coupling reaction of olefins with aryl halides and Suzuki reactions of various aryl halides with aryl boronic acids under aerobic condition.This catalytic system demonstrates great tolerance to a wide range of groups on all substrates of aryl halides,alkenes and aryl boronic acids.
基金the financial support by the Open Fund Project of Hubei Key Laboratory of Radiation Chemistry and Functional Materials (No. 2021KF07)the Research and Development Fund Project of Hubei University of Science and Technology (Nos. 2021ZX13, H2019004)Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘Polyanilines(PANIs) can be easily prepared from the available and cheap anilines via the oxidative polymerization reactions. Owing to the coordination of nitrogen in the material with metals, PANIs are widely used as the support of nano metal catalysts. In comparison with inorganic supports, the nano metals on PANIs were firmly anchored via the coordination bond so that they are not easily to lose during the reaction process. Moreover, since PANIs are versatile materials and their chemical features can be adjusted by introducing functional groups onto the monomers, the catalytic activities of the prepared catalysts are tunable. During the past decade, PANIs-supported nano metal catalysts have been widely applied in a variety of coupling reactions. This review aims to summarize the recent advances and give a perspective.
文摘CuI/ethylene diamine/K2CO3/dioxane is shown to be a useful system for the cross coupling reactions of various aryl iodides and bromides with aryl and alkyl alkynes. Compared to the conventional Sonogashira reactions, the new procedure is free of palladium and phosphines.
基金jointly supported by the National Key Research and Development Program of China (2019YFC1905800)the National Key Research & Development Program of China (2018YFC1903500)+4 种基金the commercial project by Beijing Zhong Dian Hua Yuan Environment Protection Technology Co., Ltd. (E01211200005)the Regional key projects of the science and technology service network program (STS program) of the Chinese Academy of Sciences (KFJ-STS-QYZD-153)the Ningbo Science and Technology Innovation Key Projects (2020Z099, 2022Z028)the Ningbo Municipal Commonweal Key Program (2019C10033)the support of Mineral Resources Analytical and Testing Center, Institute of Process Engineering, Chinese Academy of Science
文摘To achieve the resource utilization of solid waste phosphogypsum(PG)and tackle the problem of utilizing potassium feldspar(PF),a coupled synergistic process between PG and PF is proposed in this paper.The study investigates the features of P and F in PG,and explores the decomposition of PF using hydrofluoric acid(HF)in the sulfuric acid system for K leaching and leaching of P and F in PG.The impact factors such as sulfuric acid concentration,reaction temperature,reaction time,material ratio(PG/PF),liquid–solid ratio,PF particle size,and PF calcination temperature on the leaching of P and K is systematically investigated in this paper.The results show that under optimal conditions,the leaching rate of K and P reach more than 93%and 96%,respectively.Kinetics study using shrinking core model(SCM)indicates two significant stages with internal diffusion predominantly controlling the leaching of K.The apparent activation energies of these two stages are 11.92 kJ·mol^(-1)and 11.55 kJ·mol^(-1),respectively.
基金financially supported by the National Natural Science Foundation of China(22002084,22072081)the China Postdoctoral Science Foundation(2020M683420)+1 种基金the Fundamental Research Funds for the Central Universities(GK202103111)the 111 Project(B21005)。
文摘Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)holds great promise in green energy conversion and storage.However,for current CO_(2) electrolyzers that rely on the oxygen evolution reaction,a large portion of the input energy is"wasted"at the anode due to the high overpotential requirement and the recovery of low-value oxygen.To make efficient use of the electricity during electrolysis,coupling CO_(2)RR with anodic alternatives that have low energy demands and/or profitable returns with high-value products is then promising.Herein,we review the latest advances in paired systems for simultaneous CO_(2) reduction and anode valorization.We start with the cases integrating CO_(2)RR with concurrent alternative oxidation,such as inorganic oxidation using chloride,sulfide,ammonia and urea,and organic oxidation using alcohols,aldehydes and primary amines.The paired systems that couple CO_(2)RR with on-site oxidative upgrading of CO_(2)-reduced chemicals are also introduced.The coupling mechanism,electrochemical performance and economic viability of these co-electrolysis systems are discussed.Thereby,we then point out the mismatch issues between the cathodic and anodic reactions regrading catalyst ability,electrolyte solution and reactant supply that will challenge the applications of these paired electrolysis systems.Opportunities to address these issues are further proposed,providing some guidance for future research.
文摘Palladium(Pd)‐based catalysts are essential to drive high‐performance Suzuki coupling reactions,which are powerful tools for the synthesis of functional organic compounds.Herein,we developed a solution‐rapid‐annealing process to stabilize nitrogen‐mesoporous carbon supported Pd single‐atom/cluster(Pd/NMC)material,which provided a catalyst with superior performance for Suzuki coupling reactions.In comparison with commercial palladium/carbon(Pd/C)catalysts,the Pd/NMC catalyst exhibited significantly boosted activity(100%selectivity and 95%yield)and excellent stability(almost no decay in activity after 10 reuse cycles)for the Suzuki coupling reactions of chlorobenzenes,together with superior yield and excellent selectivity in the fields of the board scope of the reactants.Moreover,our newly developed rapid annealing process of precursor solutions is applied as a generalized method to stabilize metal clusters(e.g.Pd,Pt,Ru),opening new possibilities in the construction of efficient highly dispersed metal atom and sub‐nanometer cluster catalysts with high performance.
基金Project (No. 2004C21032) supported by the Key Technologies R &D Program of Zhejiang Province, China
文摘Sm/TiCl4 system could well integrate the high reactivity of samarium（Ⅱ） and high deoxygenation capacity of low valent titanium within one system. In this paper, the intermolecular and intramolecular reductive coupling reactions of ketones with esters mediated by metallic samarium （Sm） and a catalytic amount of titanium tetrachloride （TiCl4） were successfully developed. A series of substituted ketones and cyclic β-keto-esters were prepared in moderate to good yields under reflux and neutral conditions.
基金supported by the National Natural Science Foundation of China(No.20472079)
文摘Pinacol coupling reactions catalyzed by active zinc revealed high activity and extensive suitability. The efficiency of the reaction was improved apparently owing to decreasing reductive potential of zinc. In addition, the results indicated that the zinc activity has a direct relation to the coupling reactivity compared to untreated zinc or other general active zinc.
基金Supported by the National Natural Science Foundation of China(No.20972132)the Fund of Key Laboratory of Environmental Resource and Material,Jiangsu Province,China
文摘An efficient synthetic protocol for the 1,4-diaryl-1,4-dihydropyridines was developed via the domino four-component reaction of arylamine,acetylenedicarboxylate,aromatic aldehyde and ethyl acetoacetate.The reaction mechanism involves the formation of β-enamino ester and its sequential Michael addition to arylidene acetoacetate.
基金financial support from the National Natural Science Foundation of China (No. 22101261)。
文摘Due to the increasing demand for the sustainability of modern organic chemistry, the development of green and powerful methods for C-C and C-B bond formation is highly desired. Among them, the transition-metal-free coupling reactions of gem–diborylalkanes emerge as one valuable tool for organic chemists in the last decade. The review covers selected representative examples. A comparison of these reactions with transition-metal-catalyzed reactions is provided. The recent example of α-boryl radical formation from gem–diborylalkanes is also briefly discussed.
基金supported by the Ministry of Science and Technology of China (No.2016YFA0200603)the National Natural Science Foundation of China (No.91421313 and No.21573207)Anhui Initiative in Quantum Information Technologies (AHY090300)
文摘The chemistry of acetaldehyde (CH3CHO) adsorbed on the anatase TiO2(001)-(1×4) surface has been investigated by temperature-programmed desorption (TPD) method. Our experimental results provide the direct evidence that the perfect lattice sites on the anatase TiO2(001)-(1×4) surface are quite inert for the reaction of CH3CHO, but the reduced defect sites on the surface are active for the thermally driven reductive carbon-carbon coupling reactions of CH3CHO to produce 2-butanone and butene. We propose that the coupling reactions of CH3CHO on the anatase TiO2(001)-(1×4) surface should undergo through the adsorption of paired CH3CHO molecules at the reduced defect sites, since the existing reduced Ti pairs provide the suitable adsorption sites.
文摘Binaphthalene-core phosphepine compounds with axial chirality belong to an important class of organocatalysts and ligands used in catalytic asymmetric synthesis.However,the number and application of these compounds have been limited due to the lack of efficient synthetic methods currently available to researchers.Herein,a simple and efficient palladium-catalyzed C—P cross-coupling reaction of enantiopure(R)-1 with a variety of aryl and heteroaryl halides is reported.The reaction provides access to a series of chiral binaphthalene-core phosphepine compounds using Pd(OAc)2/dippf as a catalyst,which allows most products to be formed in moderate to high yields(40%~92%)with excellent ee values(90%~99%ee).
基金the National Natural Science Foundation of China （no. 20572096） the Zhejiang Provincial Science Foundation （Grant R405066）.
文摘An efficient route to synthesize the heteroaryl-substituted 1,8-naphthyridine derivatives was described. Eight 2-heteroaryl- and 2,7-diheteroaryl-1,8-naphthyridine derivatives were obtained through palladium-catalyzed C-N-coupling reactions of chloronaphthyridines with imidazole, benzimidazole, morpholine, 3,5-dimethylpyrazole, and phthalimide in moderate to good yields.
基金The authors are grateful for the financial support of The Sate Key Fundamental Research Project and the Natural Science Foundation of China.
文摘Dehydrogenation of ethylbenzene （EB） to styrene （ST） in the presence of CO2, in which EB dehydrogenation is coupled with the reverse water-gas shift （RWGS）, was investigated extensively through both theoretical analysis and experimental characterization. The reaction coupling proved to be superior to the single dehydrogenation in several respects. Thermodynamic analysis suggests that equilibrium conversion of EB can be improved greatly by reaction coupling due to the simultaneous elimination of the hydrogen produced from dehydrogenation. Catalytic tests proved that iron and vanadium supported on activated carbon or Al2O3 with certain promoters are potential catalysts for this coupling process. The catalysts of iron and vanadium are different in the reaction mechanism, although ST yield is always associated with CO2 conversion over various catalysts. The two-step pathway plays an important role in the coupling process over Fe/Al2O3, while the one-step pathway dominates the reaction over V/Al2O3. Coke deposition and deep reduction of active components are the major causes of catalyst deactivation. CO2 can alleviate the catalyst deactivation effectively through preserving the active species at high valence in the coupling process, though it can not suppress the coke deposition.
基金Supported by the National Natural Science Foundation of China(21176038,21576044,21536002)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(21421005)the Dalian University of Technology Innovation Team(DUT2013TB07)
文摘Three types of ligands have been developed for copper-catalyzed Ullmann cross coupling reaction of bromaminic acid with amines in aqueous solution. Ligands with large steric hindrance and strong electron-donating capacity were beneficial to the reaction. UV–Vis and CV analyses demonstrated that these ligands had strong coordination with copper(I), implying the effect of ligand coordination ability on the stability and catalytic activity of catalytic system.
文摘Combining microwave radiation with photocatalytic systems is a promising method to inhibit photogenerated electron-hole recombination and enhance the photocatalytic reaction performance. In this study, we have designed Pd/Pb TiO3 catalysts that can use both microwave fields and photocatalysis. Benefiting from the synergistic effect of microwave field and UV light, the Pb TiO3 crystals convert thermal energy into electrical energy via the pyroelectricity effect, generating positive and negative charges(q+ and q-), while Pd nanoparticles significantly improve the quantum efficiency of the photocatalytic process. The composite catalyst significantly enhances the reaction rate and selectivity of the model Suzuki coupling reaction performed with bromobenzene. Microwave fields can directly act on chemical systems, promoting or changing various chemical reactions in unique ways.
基金National Basic Research Program of China (Grants No. 2009CB940903 and 2009CB918502)the National Natural Science Foundation of China (Grant No. 20721003 and 81025017)National S&T Major Projects (Grant No. 2012ZX09103-101-072).
文摘A convenient and efficient method for the preparation of α-substituted β-amino acids has been developed by reacting compound 2 with various boric acid/borate 3 through Suzuki coupling reaction,which gave multiple structure types of substituted Ni（II） complexes 4 in high yields.Hydrogenation and hydrolysis of complexes 4 led to the corresponding α-substituted β-amino acids.
基金financially supported by Natural Science Foundation of Shandong Province(No.ZR2021MB065)the major innovation fund of Shandong Province(No.2021ZDSYS_(2)3)the National Natural Science Foundation of China(Nos.21976105,22101237).
文摘An additive-free and environmentally friendly strategy has been realized for the construction of S-substituted isothioureas through visible-light-induced multicomponent reaction starting fromα-diazoesters,aryl isothiocyanates,amines and cyclic ethers.This methodology features simple operation,mild reaction conditions,favorable functional group tolerance,easily available starting materials and high efficiency.
