Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using iso...Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using isopropanol as hydrogen source.The reaction is easily scaled up in a gram-scale synthesis using 1 mol% nickel catalyst and it is applied to an asymmetric synthesis of(S)-rivastigmine.Building on this success,we achieved rare examples of asymmetric hydrogen borrowing reactions with arylamines using an Earth-abundant 3d metal,nickel.展开更多
In this study,electrochemical C-H carboxylation of benzylamines with CO_(2) was reported.This linear paired electrolysis system enables efficient and economical synthesis of value-added α-amino acids(α-AAs) under mi...In this study,electrochemical C-H carboxylation of benzylamines with CO_(2) was reported.This linear paired electrolysis system enables efficient and economical synthesis of value-added α-amino acids(α-AAs) under mild conditions.Various substituted benzylamines containing diverse functional groups and even highly reactive moieties,such as cyano,amide and alkene groups could be successfully transformed to the carboxylated products.Notably,this method proved to be applicable to the late-stage modification of biorelevant compounds,highlighting its potential for synthetic chemistry.Mechanistic studies such as radical trapping experiments,kinetic isotope effect(KIE) tests and cyclic voltammetry(CV) studies provided useful insight into this transformation.展开更多
Herein,we have developed a sustainable linear paired electrolysis strategy for the redox-neutral benzylation of N-heteroarenes with benzyl halides using solid ion resin as the recyclable electrolyte.This method suffic...Herein,we have developed a sustainable linear paired electrolysis strategy for the redox-neutral benzylation of N-heteroarenes with benzyl halides using solid ion resin as the recyclable electrolyte.This method sufficiently utilizes both cathodic and anodic reactions to produce a variety of benzylated Nheteroarenes,features high atom-and step-economy,excellent energy efficiency,operational simplicity,good functional group tolerance,mild conditions and no requirement of sacrifice reagent and base additive.Importantly,the inexpensive and commercially available solid ion resin electrolyte was validated in both gram-scale synthesis and electrolyte cycling experiment.We hope this strategy not only provides a sustainable synthetic strategy for benzylated compounds but also develops the further utilization of ion resin in electrosynthesis as well as linear paired electrolysis.展开更多
The direct deoxygenative homo-coupling of benzyl alcohols holds great promise to build up bibenzyl motifs in organic synthesis,yet it remains a grand challenge in selectivity and activity control.Herein,we first disco...The direct deoxygenative homo-coupling of benzyl alcohols holds great promise to build up bibenzyl motifs in organic synthesis,yet it remains a grand challenge in selectivity and activity control.Herein,we first discovered that iron carbide catalysts displayed high efficiency and selectivity in the catalytic deoxygenative homo-coupling of benzyl alcohols into bibenzyls using H_(2)as the reductant.Ir-promoted Fe0@Fe_(5)C_(2)gave the best performance among the investigated catalysts,and a broad scope of substrates with diverse functional groups could be smoothly converted into bibenzyls,with the yield up to 85%.In addition,in the presence of alkenes,three-component coupling reactions between alcohols and alkenes were also for the first time achieved to construct more complex multi-ring molecules.The radical-trapping experiment and FTIR measurements revealed the radical nature of the reaction and the significantly promoted C–O bond activation after carbonization,respectively.This work will provide guidelines for the rational design of efficient and selective catalysts for the alcohol-involved carbon-carbon coupling reactions.展开更多
Although bimetallic phosphide cocatalysts have attracted considerable interest in photocatalysis research owing to their advantageous thermodynamic characteristics,superstable and efficient cocatalysts have rarely bee...Although bimetallic phosphide cocatalysts have attracted considerable interest in photocatalysis research owing to their advantageous thermodynamic characteristics,superstable and efficient cocatalysts have rarely been produced through the modulation of their structure and composition.In this study,a series of bimetallic nickel-iron phosphide(Ni_(x)Fe_(2-x)P,where 0<x<2)cocatalysts with controllable structures and overpotentials were designed by adjusting the atomic ratio of Ni/Fe onto nonmetallic elemental red phosphorus(RP)for the photocatalytic selective oxidation of benzyl alcohol(BA)coupled with hydrogen production.The catalysts exhibited an outstanding photocatalytic activity for benzaldehyde and a high H_(2)yield.The RP regulated by bimetallic phosphide cocatalysts(Ni_(x)Fe_(2-x)P)demonstrated higher photocatalytic oxidation-reduction activity than that regulated by monometallic phosphide cocatalysts(Ni_(2)P and Fe2P).In particular,the RP regulated by Ni_(1.25)Fe_(0.75)P exhibited the best photocatalytic performance.In addition,experimental and theoretical calculations further illustrated that Ni_(1.25)Fe_(0.75)P,with the optimized electronic structure,possessed good electrical conductivity and provided strong adsorption and abundant active sites,thereby accelerating electron migration and lowering the reaction energy barrier of RP.This finding offers valuable insights into the rational design of highly effective cocatalysts aimed at optimizing the photocatalytic activity of composite photocatalysts.展开更多
A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized wi...A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized with high chemoselectivity under mild conditions.Moreover,the mild conditions by using air as the oxidant render the developed proto-col more ecofriendly and environmentally sustainable.展开更多
Ni_(2)CoS_(4)was prepared by the liquid‑phase method and applied to the benzyl alcohol electro‑oxidation reaction(BAOR),demonstrating excellent catalytic activity[with a current density of 271 mA·cm^(-2)at 1.40 V...Ni_(2)CoS_(4)was prepared by the liquid‑phase method and applied to the benzyl alcohol electro‑oxidation reaction(BAOR),demonstrating excellent catalytic activity[with a current density of 271 mA·cm^(-2)at 1.40 V(vs RHE)]and long‑term stability.The S‑anion effect can regulate the charge distribution on the catalyst surface,thereby enhancing the additional adsorption capacity of OH-at the Co sites.By combining material characterization and theoretical calculations,it can be observed that this process can increase the concentration of the OH^(*)intermediate,accelerate the activation process of the Ni site,and ultimately achieve an improvement in overall activity and stability.展开更多
The development of efficient photocatalysts for selective organic transformations under visible light remains a major challenge in sustainable chemistry.In this study,we present a straightforward solvothermal strategy...The development of efficient photocatalysts for selective organic transformations under visible light remains a major challenge in sustainable chemistry.In this study,we present a straightforward solvothermal strategy for fabricating a defect-engineered ZrO_(2)/UiO-66-NH_(2)hybrid material with abundant oxygen vacancies,enabling the visible-light-driven oxidation of benzyl alcohol to benzaldehyde.By optimizing the solvothermal treatment duration,the composite(UiO-66-NH_(2)-2h)achieves a 74.1%conversion of benzyl alcohol with>99%selectivity toward benzaldehyde under mild conditions,substantially out-performing pristine UiO-66-NH_(2).Structural and mechanistic studies reveal that the solvothermal process induces the in situ formation of ultrasmall,uniformly dispersed ZrO_(2)nanoparticles(~2.3 nm)within the MOF matrix,while simultaneously generating abundant oxygen vacancies,as confirmed by XPS,EPR,and HRTEM analyses.The defect-mediated electronic structure of the ZrO_(2)/UiO-66-NH_(2)hybrid enhances visible-light absorption,facilitates charge carrier separation,and pro-motes efficient activation of O_(2)into superoxide radicals(·O_(2)^(−)),the primary reactive species.Transient photocurrent measure-ments and electrochemical impedance spectroscopy further verify the improved charge separation efficiency.The synergistic interplay between oxygen vacancies and the intimate ZrO_(2)/UiO-66-NH_(2)interface provides a unique defect-mediated charge transfer pathway,distinguishing this system from conventional heterojunctions.This study demonstrates a facile,one-step approach to integrate defect engineering with interfacial hybridization in MOF-based photocatalysts,off ering a scalable route for solar-driven organic synthesis.展开更多
A biodegradable and green organic compound octadecyl dimethyl benzyl amm-onium chloride(ODBAC)was used as an efficient inhibitor for cold rolled steel(CRS)in phosphoric acid(H_(3)PO_(4)).The mechanism of adsorption an...A biodegradable and green organic compound octadecyl dimethyl benzyl amm-onium chloride(ODBAC)was used as an efficient inhibitor for cold rolled steel(CRS)in phosphoric acid(H_(3)PO_(4)).The mechanism of adsorption and film formation of ODBAC on CRS was studied through experimental and theoretical calculations.The weight loss method shows that the inhibition efficiency of ODBAC can reach 92.01%at a concentration of 10 mg·L^(-1).The adsorption of ODBAC on the CRS surface conforms to the Langmuir isotherm model,which is a mixed adsorption mainly based on physical adsorption.The X-ray photoelectron spectroscopy(XPS)and contact angle results confirmed the existence of the ODBAC film and steel surface's hydrophobicity has been significantly enhanced.Electrochemical test results reveal that the film's formation mainly inhibits the cathodic corrosion reaction and effectively increases the charge transfer resistance.Quantum chemical calculations have found that N18 in ODBAC and C24 and C25 on the benzene ring are the key active adsorption sites.Molecular dynamics simulation results indicate that ODBAC can sharply reduce the free fraction volume to 8%and inhibit the diffusion of corrosion particles,meaning that the formed ODBAC film makes it difficult for corrosion particles to penetrate,thus improving the corrosion resistance of CRS in H_(3)PO_(4).展开更多
Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was ...Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was systematically studied over plane clay （K-10, montmorillonite）, plane H-Beta, plane MFI structured titanosilicate （TS-1） and heteropoly acids [HPA, namely dodecatungstophosphoric acid [H3PO4.12WOa-xH2O] （TPA）, dodeca-molybdo phosphoric acid ammonium salt hydrate [H12Mo12N3040P＋aq] （DMAA）, sodium tungstate hydrated purified [Na12WO4.2H2O] （STH）] supported on clay, H-beta and TS-1. The 20%TPA/Clay, 30%TPA/H-Beta and 30%TPA/TS-1, were observed to be the best catalyst samples over plane clay, plane H-Beta and plane TS-1. The catalyst samples are compared with respect to benzyl chloride conversion and selectivities for diphenylmethane, dimethyl-diphenylmethane, benzyl toluene and benzoic acid. The reaction follows the pseudo-first order rate power law model. The apparent rate constants are calculated and compared with the reported ones.展开更多
NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemosele...NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation.展开更多
A new debenzylation of benzyl esters by silica-supported sodium hydrogen sulfate is described. The debenzylation could be achieved selectively and efficiently in good to excellent yields without affecting sensitive fu...A new debenzylation of benzyl esters by silica-supported sodium hydrogen sulfate is described. The debenzylation could be achieved selectively and efficiently in good to excellent yields without affecting sensitive functional groups such as nitro, unsaturated bonds, and ethyl ester.展开更多
Ag-based nanocatalysts exhibit good catalytic activity for the electrochemical reduction of organic halides. Ag-Ni alloy nanoparticles（NPs） were facilely prepared by chemical reduction, and the as-prepared nanocatal...Ag-based nanocatalysts exhibit good catalytic activity for the electrochemical reduction of organic halides. Ag-Ni alloy nanoparticles（NPs） were facilely prepared by chemical reduction, and the as-prepared nanocatalysts were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The electrocatalytic activity of Ag-Ni NPs for benzyl chloride reduction was studied in organic medium using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results show that the addition of Ni element can obviously decrease the size of Ag-Ni NPs, shift the reduction peak potential（φp） of benzyl chloride positively, and increase the catalytic activity of Ag-Ni NPs. However, when the Ni content reaches a certain value, the catalytic activity of Ag-Ni NPs decreases. Meanwhile, the synergistic catalytic effect of Ag-Ni NPs was also discussed.展开更多
A highly efficient benzylation of arenes and heteroarenes catalyzed by HfCl4/HfO2 has been developed. Broad scope of benzylation reagents have been used in this process with high yields under mild condition. Additiona...A highly efficient benzylation of arenes and heteroarenes catalyzed by HfCl4/HfO2 has been developed. Broad scope of benzylation reagents have been used in this process with high yields under mild condition. Additionally, the HfO2 can be re-used after the reaction. ？2009 Xin Qin Gao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
In the presence of Nafion/SiO2 nanocomposite catalyst, the benzylation of aromatic compounds with benzyl chloride proceeded to afford diphenylmethane derivatives in high yields. The catalyst showed high catalytic ac...In the presence of Nafion/SiO2 nanocomposite catalyst, the benzylation of aromatic compounds with benzyl chloride proceeded to afford diphenylmethane derivatives in high yields. The catalyst showed high catalytic activity not only for electron-rich aromatic compounds, but also for electron-poor aromatic compounds. Under identical conditions, the self-benzylation of benzyl chloride, and dibenzylation and/or multi-benzylation of aromatic compounds were negligible.展开更多
A route was proposed to synthesize 3-benzyl-glyceric acid (3-BGA) as an important intermediate for the synthesis of a novel six-membered cyclic ester monomer-3-benzyloxymethyl-1,4-dioxane-2,5-dione (3-BMG). According ...A route was proposed to synthesize 3-benzyl-glyceric acid (3-BGA) as an important intermediate for the synthesis of a novel six-membered cyclic ester monomer-3-benzyloxymethyl-1,4-dioxane-2,5-dione (3-BMG). According to this route, 3-BGA was obtained from ring-opening reaction of benzyl alcohol with methyl glycidate, which was prepared from the epoxidation of methyl acrylate using sodium hypochlorite as the oxidant.展开更多
o-Bromomethylbenzylidenemalononitrile 4 is reduced by 1-benzyl-1,4-dihydronicotinamide (BNAH, 1) to give 2,2-indanedicarbonitrile 6 and p-bromomethylbenzylidenemalononitrile 5 is reduced by BNAH to give 7 and 8 by hyd...o-Bromomethylbenzylidenemalononitrile 4 is reduced by 1-benzyl-1,4-dihydronicotinamide (BNAH, 1) to give 2,2-indanedicarbonitrile 6 and p-bromomethylbenzylidenemalononitrile 5 is reduced by BNAH to give 7 and 8 by hydride transfer mechanism.展开更多
Benzyl benzoate(BB),an important ester,still demands for green synthesis routes.In this work,by size regula-tion and proper functionalization of carbon nanotubes(CNTs)as the support of gold catalyst,this ester can be ...Benzyl benzoate(BB),an important ester,still demands for green synthesis routes.In this work,by size regula-tion and proper functionalization of carbon nanotubes(CNTs)as the support of gold catalyst,this ester can be synthesized very efficiently directly from benzyl alcohol via oxidative coupling.More attractively,the reaction is performed using water as green solvent and molecular oxygen as green oxidant.Simultaneously,very high selectivity to BB can be obtained near full conversion within very short reaction time(just 0.5 h),while the low-value benzoic acid byproduct is negligible.This is very different from many reported gold catalysts that yield much benzoic acid and/or benzaldehyde in water.The results show that,besides the size of CNTs(length and diameter),the functionalization of CNTs is also critical for improving both conversion and the selectivity to BB.In addition,the reaction mechanism for forming BB ester is put forward as well.展开更多
Objective:To determine the content of benzyl glueosinolate（BG） in the pulp and the seed and investigate the anti-cuncer activity of its hydrolysis product in Curica papaya L.Methods: Determination of BG was performe...Objective:To determine the content of benzyl glueosinolate（BG） in the pulp and the seed and investigate the anti-cuncer activity of its hydrolysis product in Curica papaya L.Methods: Determination of BG was performed on an Hypersil BDS C<sub>18</sub> column at the wavelength of 214 nm with 0.1%trifluoroacelic acid（TFA） aqueous solution（A） and 0.1%TFA acelonilrile（B） as the mobile phase.In vitro activity test was adopted with cidtured human lung cancer H69 cell in vitro to investigate the inhibition rate of cell proliferation of benzyl isothiocyanale（BITC） againsl H69 cell.Results:The pulp has more BG before the maturation of papaya and it nearly disappeared after papaya matured,while the seed contains BG at every stage.Activity test demonstrated that the a higher concentration of BITC would have betler inhibition rate of cell proliferation on 1169 cell,and the IC<sub>50</sub> was 6.5μmol/L.Conclusions:BG also can be produced in the pulp of papaya and it will be stored in the seed after the fruit has been matured.The hydrolysis product of BG has certain cancer-prevention anti-cancer activities for human.展开更多
Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolu...Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolution and benzaldehyde production by dehydrogenation of benzyl alcohol over Nidecorated Zn_(0.5)Cd_(0.5)S solid solution under visible light. The photocatalytic system shows an excellent hydrogen production rate of 666.3 μmol h^(-1) with high stability. The optimal apparent quantum yield of52.5% is obtained at 420 nm. This noble-metal-free photocatalytic system displays much higher activity than pure Zn_(0.5)Cd_(0.5)S and Pt-loaded Zn_(0.5)Cd_(0.5)S solid solution. Further studies reveal that the metallic Ni nanocrystals play an important role in accelerating the separation of photogenerated charge carriers and the subsequent cleavage of α-C–H bond during dehydrogenation of benzyl alcohol.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22271007,W2431014)Peking University Shenzhen Graduate School+2 种基金State Key Laboratory of Chemical OncogenomicsShenzhen Key Laboratory of Chemical GenomicsShenzhen Bay Laboratory.
文摘Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using isopropanol as hydrogen source.The reaction is easily scaled up in a gram-scale synthesis using 1 mol% nickel catalyst and it is applied to an asymmetric synthesis of(S)-rivastigmine.Building on this success,we achieved rare examples of asymmetric hydrogen borrowing reactions with arylamines using an Earth-abundant 3d metal,nickel.
基金Financial support from National Key R&D Program of China (No.2023YFA1507203)National Natural Science Foundation of China (Nos.22371149 and 22188101)+3 种基金the Fundamental Research Funds for the Central Universities (No.63224098)Frontiers Science Center for New Organic Matter,Nankai University (No.63181206)Nankai University are gratefully acknowledgedthe Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘In this study,electrochemical C-H carboxylation of benzylamines with CO_(2) was reported.This linear paired electrolysis system enables efficient and economical synthesis of value-added α-amino acids(α-AAs) under mild conditions.Various substituted benzylamines containing diverse functional groups and even highly reactive moieties,such as cyano,amide and alkene groups could be successfully transformed to the carboxylated products.Notably,this method proved to be applicable to the late-stage modification of biorelevant compounds,highlighting its potential for synthetic chemistry.Mechanistic studies such as radical trapping experiments,kinetic isotope effect(KIE) tests and cyclic voltammetry(CV) studies provided useful insight into this transformation.
基金financial support from University of South China。
文摘Herein,we have developed a sustainable linear paired electrolysis strategy for the redox-neutral benzylation of N-heteroarenes with benzyl halides using solid ion resin as the recyclable electrolyte.This method sufficiently utilizes both cathodic and anodic reactions to produce a variety of benzylated Nheteroarenes,features high atom-and step-economy,excellent energy efficiency,operational simplicity,good functional group tolerance,mild conditions and no requirement of sacrifice reagent and base additive.Importantly,the inexpensive and commercially available solid ion resin electrolyte was validated in both gram-scale synthesis and electrolyte cycling experiment.We hope this strategy not only provides a sustainable synthetic strategy for benzylated compounds but also develops the further utilization of ion resin in electrosynthesis as well as linear paired electrolysis.
文摘The direct deoxygenative homo-coupling of benzyl alcohols holds great promise to build up bibenzyl motifs in organic synthesis,yet it remains a grand challenge in selectivity and activity control.Herein,we first discovered that iron carbide catalysts displayed high efficiency and selectivity in the catalytic deoxygenative homo-coupling of benzyl alcohols into bibenzyls using H_(2)as the reductant.Ir-promoted Fe0@Fe_(5)C_(2)gave the best performance among the investigated catalysts,and a broad scope of substrates with diverse functional groups could be smoothly converted into bibenzyls,with the yield up to 85%.In addition,in the presence of alkenes,three-component coupling reactions between alcohols and alkenes were also for the first time achieved to construct more complex multi-ring molecules.The radical-trapping experiment and FTIR measurements revealed the radical nature of the reaction and the significantly promoted C–O bond activation after carbonization,respectively.This work will provide guidelines for the rational design of efficient and selective catalysts for the alcohol-involved carbon-carbon coupling reactions.
文摘Although bimetallic phosphide cocatalysts have attracted considerable interest in photocatalysis research owing to their advantageous thermodynamic characteristics,superstable and efficient cocatalysts have rarely been produced through the modulation of their structure and composition.In this study,a series of bimetallic nickel-iron phosphide(Ni_(x)Fe_(2-x)P,where 0<x<2)cocatalysts with controllable structures and overpotentials were designed by adjusting the atomic ratio of Ni/Fe onto nonmetallic elemental red phosphorus(RP)for the photocatalytic selective oxidation of benzyl alcohol(BA)coupled with hydrogen production.The catalysts exhibited an outstanding photocatalytic activity for benzaldehyde and a high H_(2)yield.The RP regulated by bimetallic phosphide cocatalysts(Ni_(x)Fe_(2-x)P)demonstrated higher photocatalytic oxidation-reduction activity than that regulated by monometallic phosphide cocatalysts(Ni_(2)P and Fe2P).In particular,the RP regulated by Ni_(1.25)Fe_(0.75)P exhibited the best photocatalytic performance.In addition,experimental and theoretical calculations further illustrated that Ni_(1.25)Fe_(0.75)P,with the optimized electronic structure,possessed good electrical conductivity and provided strong adsorption and abundant active sites,thereby accelerating electron migration and lowering the reaction energy barrier of RP.This finding offers valuable insights into the rational design of highly effective cocatalysts aimed at optimizing the photocatalytic activity of composite photocatalysts.
文摘A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized with high chemoselectivity under mild conditions.Moreover,the mild conditions by using air as the oxidant render the developed proto-col more ecofriendly and environmentally sustainable.
文摘Ni_(2)CoS_(4)was prepared by the liquid‑phase method and applied to the benzyl alcohol electro‑oxidation reaction(BAOR),demonstrating excellent catalytic activity[with a current density of 271 mA·cm^(-2)at 1.40 V(vs RHE)]and long‑term stability.The S‑anion effect can regulate the charge distribution on the catalyst surface,thereby enhancing the additional adsorption capacity of OH-at the Co sites.By combining material characterization and theoretical calculations,it can be observed that this process can increase the concentration of the OH^(*)intermediate,accelerate the activation process of the Ni site,and ultimately achieve an improvement in overall activity and stability.
基金the National Natural Sci-ence Foundation of China(Nos.22271038,22378038,22172012)C.P.thanks Dalian Science and Technology Innovation Fund(No.2024JJ12CG033)+1 种基金C.P.and Z.S thank State Key Laboratory of Heavy Oil Processing(Nos.WX20230149,SKLHOP202402005)Y.-Y.L.thanks the Guangxi Key Laboratory of Information Materials,Guilin University of Electronic Technology(No.231019-K).
文摘The development of efficient photocatalysts for selective organic transformations under visible light remains a major challenge in sustainable chemistry.In this study,we present a straightforward solvothermal strategy for fabricating a defect-engineered ZrO_(2)/UiO-66-NH_(2)hybrid material with abundant oxygen vacancies,enabling the visible-light-driven oxidation of benzyl alcohol to benzaldehyde.By optimizing the solvothermal treatment duration,the composite(UiO-66-NH_(2)-2h)achieves a 74.1%conversion of benzyl alcohol with>99%selectivity toward benzaldehyde under mild conditions,substantially out-performing pristine UiO-66-NH_(2).Structural and mechanistic studies reveal that the solvothermal process induces the in situ formation of ultrasmall,uniformly dispersed ZrO_(2)nanoparticles(~2.3 nm)within the MOF matrix,while simultaneously generating abundant oxygen vacancies,as confirmed by XPS,EPR,and HRTEM analyses.The defect-mediated electronic structure of the ZrO_(2)/UiO-66-NH_(2)hybrid enhances visible-light absorption,facilitates charge carrier separation,and pro-motes efficient activation of O_(2)into superoxide radicals(·O_(2)^(−)),the primary reactive species.Transient photocurrent measure-ments and electrochemical impedance spectroscopy further verify the improved charge separation efficiency.The synergistic interplay between oxygen vacancies and the intimate ZrO_(2)/UiO-66-NH_(2)interface provides a unique defect-mediated charge transfer pathway,distinguishing this system from conventional heterojunctions.This study demonstrates a facile,one-step approach to integrate defect engineering with interfacial hybridization in MOF-based photocatalysts,off ering a scalable route for solar-driven organic synthesis.
基金support from National Natural Science Foundation of China(52161016)Joint Key Project of Agricultural Fundamental Research in Yunnan Province(202101BD070001-017)+2 种基金Yunnan Provincial Academician Workstation(202305AF150009)Special Project of“Top Young Talents”of Yunnan Ten Thousand Talents Plan(51900109)Special Project of“Leading Talents of Industrial Technology”of Yunnan Ten Thousand Talents Plan(80201408)are acknowledged.
文摘A biodegradable and green organic compound octadecyl dimethyl benzyl amm-onium chloride(ODBAC)was used as an efficient inhibitor for cold rolled steel(CRS)in phosphoric acid(H_(3)PO_(4)).The mechanism of adsorption and film formation of ODBAC on CRS was studied through experimental and theoretical calculations.The weight loss method shows that the inhibition efficiency of ODBAC can reach 92.01%at a concentration of 10 mg·L^(-1).The adsorption of ODBAC on the CRS surface conforms to the Langmuir isotherm model,which is a mixed adsorption mainly based on physical adsorption.The X-ray photoelectron spectroscopy(XPS)and contact angle results confirmed the existence of the ODBAC film and steel surface's hydrophobicity has been significantly enhanced.Electrochemical test results reveal that the film's formation mainly inhibits the cathodic corrosion reaction and effectively increases the charge transfer resistance.Quantum chemical calculations have found that N18 in ODBAC and C24 and C25 on the benzene ring are the key active adsorption sites.Molecular dynamics simulation results indicate that ODBAC can sharply reduce the free fraction volume to 8%and inhibit the diffusion of corrosion particles,meaning that the formed ODBAC film makes it difficult for corrosion particles to penetrate,thus improving the corrosion resistance of CRS in H_(3)PO_(4).
文摘Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was systematically studied over plane clay （K-10, montmorillonite）, plane H-Beta, plane MFI structured titanosilicate （TS-1） and heteropoly acids [HPA, namely dodecatungstophosphoric acid [H3PO4.12WOa-xH2O] （TPA）, dodeca-molybdo phosphoric acid ammonium salt hydrate [H12Mo12N3040P＋aq] （DMAA）, sodium tungstate hydrated purified [Na12WO4.2H2O] （STH）] supported on clay, H-beta and TS-1. The 20%TPA/Clay, 30%TPA/H-Beta and 30%TPA/TS-1, were observed to be the best catalyst samples over plane clay, plane H-Beta and plane TS-1. The catalyst samples are compared with respect to benzyl chloride conversion and selectivities for diphenylmethane, dimethyl-diphenylmethane, benzyl toluene and benzoic acid. The reaction follows the pseudo-first order rate power law model. The apparent rate constants are calculated and compared with the reported ones.
文摘NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation.
基金support from National Science Foundation of China(Nos.03772648 and 30721005)Knowledge Innovation Program of the Chinese Academy of Sciences(No.06G8031014)
文摘A new debenzylation of benzyl esters by silica-supported sodium hydrogen sulfate is described. The debenzylation could be achieved selectively and efficiently in good to excellent yields without affecting sensitive functional groups such as nitro, unsaturated bonds, and ethyl ester.
基金Projects(2127106951238002+3 种基金J1210040J1103312)supported by the National Natural Science Foundation of ChinaProject(2013GK3015)supported by the Science and Technology Project of Hunan ProvinceChina
文摘Ag-based nanocatalysts exhibit good catalytic activity for the electrochemical reduction of organic halides. Ag-Ni alloy nanoparticles（NPs） were facilely prepared by chemical reduction, and the as-prepared nanocatalysts were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The electrocatalytic activity of Ag-Ni NPs for benzyl chloride reduction was studied in organic medium using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results show that the addition of Ni element can obviously decrease the size of Ag-Ni NPs, shift the reduction peak potential（φp） of benzyl chloride positively, and increase the catalytic activity of Ag-Ni NPs. However, when the Ni content reaches a certain value, the catalytic activity of Ag-Ni NPs decreases. Meanwhile, the synergistic catalytic effect of Ag-Ni NPs was also discussed.
文摘A highly efficient benzylation of arenes and heteroarenes catalyzed by HfCl4/HfO2 has been developed. Broad scope of benzylation reagents have been used in this process with high yields under mild condition. Additionally, the HfO2 can be re-used after the reaction. ？2009 Xin Qin Gao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘In the presence of Nafion/SiO2 nanocomposite catalyst, the benzylation of aromatic compounds with benzyl chloride proceeded to afford diphenylmethane derivatives in high yields. The catalyst showed high catalytic activity not only for electron-rich aromatic compounds, but also for electron-poor aromatic compounds. Under identical conditions, the self-benzylation of benzyl chloride, and dibenzylation and/or multi-benzylation of aromatic compounds were negligible.
基金This work was supported by the Major State Basic Research Program of China (No. G1999064704).
文摘A route was proposed to synthesize 3-benzyl-glyceric acid (3-BGA) as an important intermediate for the synthesis of a novel six-membered cyclic ester monomer-3-benzyloxymethyl-1,4-dioxane-2,5-dione (3-BMG). According to this route, 3-BGA was obtained from ring-opening reaction of benzyl alcohol with methyl glycidate, which was prepared from the epoxidation of methyl acrylate using sodium hypochlorite as the oxidant.
文摘o-Bromomethylbenzylidenemalononitrile 4 is reduced by 1-benzyl-1,4-dihydronicotinamide (BNAH, 1) to give 2,2-indanedicarbonitrile 6 and p-bromomethylbenzylidenemalononitrile 5 is reduced by BNAH to give 7 and 8 by hydride transfer mechanism.
基金Financial support from the Program for the National Natural Science Foundation of China(No.21403143)LiaoNing Revitalization Talents Program(No.XLYC1907167)Key projects of LiaoNing Natural Sci-ence Foundation(No.20180510007)is gratefully acknowledged.
文摘Benzyl benzoate(BB),an important ester,still demands for green synthesis routes.In this work,by size regula-tion and proper functionalization of carbon nanotubes(CNTs)as the support of gold catalyst,this ester can be synthesized very efficiently directly from benzyl alcohol via oxidative coupling.More attractively,the reaction is performed using water as green solvent and molecular oxygen as green oxidant.Simultaneously,very high selectivity to BB can be obtained near full conversion within very short reaction time(just 0.5 h),while the low-value benzoic acid byproduct is negligible.This is very different from many reported gold catalysts that yield much benzoic acid and/or benzaldehyde in water.The results show that,besides the size of CNTs(length and diameter),the functionalization of CNTs is also critical for improving both conversion and the selectivity to BB.In addition,the reaction mechanism for forming BB ester is put forward as well.
基金Supported by National Key Technologies R & D Program of China (2009BADA2B02-04)Natural Science Fund of Hainan Province(No.309042)Natural Science Fund of China(No.31171822)
文摘Objective:To determine the content of benzyl glueosinolate（BG） in the pulp and the seed and investigate the anti-cuncer activity of its hydrolysis product in Curica papaya L.Methods: Determination of BG was performed on an Hypersil BDS C<sub>18</sub> column at the wavelength of 214 nm with 0.1%trifluoroacelic acid（TFA） aqueous solution（A） and 0.1%TFA acelonilrile（B） as the mobile phase.In vitro activity test was adopted with cidtured human lung cancer H69 cell in vitro to investigate the inhibition rate of cell proliferation of benzyl isothiocyanale（BITC） againsl H69 cell.Results:The pulp has more BG before the maturation of papaya and it nearly disappeared after papaya matured,while the seed contains BG at every stage.Activity test demonstrated that the a higher concentration of BITC would have betler inhibition rate of cell proliferation on 1169 cell,and the IC<sub>50</sub> was 6.5μmol/L.Conclusions:BG also can be produced in the pulp of papaya and it will be stored in the seed after the fruit has been matured.The hydrolysis product of BG has certain cancer-prevention anti-cancer activities for human.
基金financially supported by the National Key Research and Development Program of China(2017YFA0402800)the National Natural Science Foundation of China(grant nos.51772285,21473170)the Fundamental Research Funds for the Central Universities
文摘Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolution and benzaldehyde production by dehydrogenation of benzyl alcohol over Nidecorated Zn_(0.5)Cd_(0.5)S solid solution under visible light. The photocatalytic system shows an excellent hydrogen production rate of 666.3 μmol h^(-1) with high stability. The optimal apparent quantum yield of52.5% is obtained at 420 nm. This noble-metal-free photocatalytic system displays much higher activity than pure Zn_(0.5)Cd_(0.5)S and Pt-loaded Zn_(0.5)Cd_(0.5)S solid solution. Further studies reveal that the metallic Ni nanocrystals play an important role in accelerating the separation of photogenerated charge carriers and the subsequent cleavage of α-C–H bond during dehydrogenation of benzyl alcohol.
