Catalytic dehydrogenative aromatization(CDA)has emerged as a powerful strategy for the synthesis of substituted phenols.However,most of the known CDA methods suffer from limited functional group compatibility due to t...Catalytic dehydrogenative aromatization(CDA)has emerged as a powerful strategy for the synthesis of substituted phenols.However,most of the known CDA methods suffer from limited functional group compatibility due to the use of strong oxidants,reductants,or bases.Herein,we report a(cis-P_(2)Cl)Ir-catalyzed CDA reaction enabled by transfer dehydrogenation(TD).This catalytic system is effective for CDA of both cyclohexanone and cyclohexanol derivatives and demonstrates excellent tolerance toward a variety of functional groups,including readily oxidizable electron-rich heterocycles.DFT studies further reveal that the(cis-P_(2)Cl)Ir catalyst is thermodynamically disfavored for the formation of a potential out-of-cycle catalyst species,iridium phenoxyl hydride complex,via oxidative addition of the phenol O–H bond,thereby preventing catalyst inhibition observed in the previously reported TD system.展开更多
Enones are widely explored in synthetic chemistry as fundamental building blocks for a wide range of reactions and exhibit intriguing biological activities that are pivotal for drug discovery.The development of synthe...Enones are widely explored in synthetic chemistry as fundamental building blocks for a wide range of reactions and exhibit intriguing biological activities that are pivotal for drug discovery.The development of synthetic strategies for highly efficient preparation of enones thereby receives intense attention,in particular through the transition metal-catalyzed coupling reactions.Here,we describe a carbene-catalyzed cross dehydrogenative coupling(CDC)reaction that enables effective assembly of simple aldehydes and alkenes to afford a diverse set of enone derivatives.Mechanistically,the in situ generated aryl radical is pivotal to“activate”the alkene by forming an allyl radical through intermolecular hydrogen atom transfer(HAT)pathway and thus forging the carbon-carbon bond formation with aldehyde as the acyl synthon.Notably,our method represents the first example on the enone synthesis through coupling of“non-functionalized”aldehydes and alkenes as coupling partners,and offers a distinct organocatalytic pathway to the transition metal-catalyzed coupling transformations.展开更多
Exploring stable and robust catalysts to replace the current toxic CuCr based catalysts for dehydrogenative coupling of ethanol to ethyl acetate is a challenging but promising task.Herein,novel NiIn based catalysts we...Exploring stable and robust catalysts to replace the current toxic CuCr based catalysts for dehydrogenative coupling of ethanol to ethyl acetate is a challenging but promising task.Herein,novel NiIn based catalysts were developed by tailoring Ni catalysts with Indium(In)for this reaction.Over the optimal Ni0.1Zn0.7Al0.3InOx catalyst,the ethyl acetate selectivity reached 90.1%at 46.2%ethanol conversion under the conditions of 548 K and a weight hourly space velocity of 1.9 h^(-1)in the 370 h time on stream.Moreover,the ethyl acetate productivity surpassed 1.1 g_(ethyl acetate)g_(catalyst)^(-1)h^(-1),,one of the best performance in current works.According to catalyst characterizations and conditional experiments,the active sites for dehydrogenative coupling of ethanol to ethyl acetate were proved to be Ni4In alloys.The presence of In tailored the chemical properties of Ni,and subsequently inhibited the C-C cracking and/or condensation reactions during ethanol conversions.Over Ni4In alloy sites,ethanol was dehydrogenated into acetaldehyde,and then transformed into acetyl species with the removal of H atoms.Finally,the coupling between acetyl species and surface-abundant ethoxyde species into ethyl acetate was achieved,affording a high ethyl acetate selectivity and catalyst stability.展开更多
An environmentally friendly method for the synthesis of 3‐organylselenyl quinolones through theelectrochemical cross‐dehydrogenative coupling of 4‐quinolones and diorganyl diselenides wasdeveloped.As a green,atom e...An environmentally friendly method for the synthesis of 3‐organylselenyl quinolones through theelectrochemical cross‐dehydrogenative coupling of 4‐quinolones and diorganyl diselenides wasdeveloped.As a green,atom economic and self‐separating process,the present reaction requiresneither external oxidants nor electrolytes,forming a recyclable catalytic system.展开更多
At atmospheric pressure and ambient temperature, pulse corona induced plasma was used as a new method for dehydrogenative coupling of methane. The synergism of plasma and catalyst on dehydrogenative coupling of metha...At atmospheric pressure and ambient temperature, pulse corona induced plasma was used as a new method for dehydrogenative coupling of methane. The synergism of plasma and catalyst on dehydrogenative coupling of methane was investigated. Experimental results have revealed that the synergism does exist, when positive corona within a suitable power range and an intermediate pulse repetition frequency (PRF) for a loaded 7-Mn2O3/7-A12O3 catalyst were chosen. In respect to the mechanism approach, a tentative model for general pathway was proposed to explain the role of plasma and catalyst partaking in the process of methane decomposition and C2 products formation.展开更多
Preparation of chemically recyclable polyesters by ring-opening polymerization(ROP)has made a considerable progress over the past few years.However,this method involves cumbersome synthesis and minimal functional dive...Preparation of chemically recyclable polyesters by ring-opening polymerization(ROP)has made a considerable progress over the past few years.However,this method involves cumbersome synthesis and minimal functional diversity of cyclic monomers.Therefore,it is of great significance to develop novel polymerization methods for direct polymerization of commercially available monomers to prepare recyclable polyesters with versatile functionalities.In present work,we report dehydrogenative copolymerization of commercialα,ω-diols to afford high molecular weight chemically recyclable aliphatic copolyesters(65.7 kg·mol^(-1))by using commercially available Milstein catalyst precursor.The thermal properties of the obtained copolymers could be finely tuned by simply adjusting the feeding ratio of two monomers.The incorporation of aliphatic or aromatic rings into polyester mainchain via copolymerization of 1,10-decanediol with 1,4-cyclohexanedimethanol and 1,4-benzenedimethanol could significantly improve the thermal properties of the resulting copolymers.More importantly,the obtained copolyesters were able to completely depolymerize back to original diols via hydrogenation by the same catalyst in solvent-free and mild conditions,thus offering a green and cost-effective route toward the preparation of widely used polyesters.展开更多
An intramolecular dehydrogenative homo-and hetero-coupling of phenols has been successfully developed for quick preparation of enantiopure axial diphenols under mild Cu(Ⅱ)-mediated conditions,using((4 S,5 S)-2,2-dime...An intramolecular dehydrogenative homo-and hetero-coupling of phenols has been successfully developed for quick preparation of enantiopure axial diphenols under mild Cu(Ⅱ)-mediated conditions,using((4 S,5 S)-2,2-dimethyl-1,3-dioxolane-4,5-diyl)dimethanol as the chiral auxiliary.The commercially available(R)-α-met hylbenzy la mine was identified as the best amine ligand for Cu(Ⅱ) in the reactions.A variety of homo/hetero bis-dihydroxylbenzoate substrates were examined,affording the corresponding axially chiral diphenols with satis factory to excellent diastereomeric ratios,and a representative scalable preparation was also attempted.A formal synthesis of natural product(+)-deoxyschizandrin has been achieved in this work using one axially chiral diphenol as the synthetic intermediate.展开更多
In this review,development of supported catalysts for the dehydrogenative synthesis of benzimidazoles from primary alcohols and 1,2-phenyIenediamine derivatives is briefly summarized.Among them,titania-supported iridi...In this review,development of supported catalysts for the dehydrogenative synthesis of benzimidazoles from primary alcohols and 1,2-phenyIenediamine derivatives is briefly summarized.Among them,titania-supported iridium catalysts showed excellent activities under mild reaction conditions.Remarkably,the low-temperature activity of iridium catalyst was significantly affected by titania supports,and the reaction of 1,2-phenylenediamine and benzyl alcohol in the presence of rutilesupported catalysts proceeded smoothly at 100℃to give 2-phenylbenzimidazole in high yields of up to 88%,On the other hand,catalysts supported on anatase generally showed poor activity at 100℃.A significant relationship between CO uptake and the activity of titania-supported catalysts has been reported,indicating that well-reduced iridium species on rutile would be responsible for the predominant catalytic activity.The present results suggest the importance of the selection of suitable titania supports for the iridium catalysts.展开更多
The transition metal-catalyzed acceptorless dehydrogenative coupling of alcohols and amines is one of the attractive and important strategies for the construction of C=N bonds from the perspective of environmental fri...The transition metal-catalyzed acceptorless dehydrogenative coupling of alcohols and amines is one of the attractive and important strategies for the construction of C=N bonds from the perspective of environmental friendliness and economy.Herein,we report the synthesis of four novel phosphine-free cobalt(II)complexes(Co-1—Co-4)with N,O-bidentate ligands incorporating N-oxide units and their catalytic activity in acceptorless dehydrogenative coupling of benzylic alcohols and aryl amines.X-ray diffraction analyses revealed that the central cobalt atoms in three of the cobalt complexes(Co-1,Co-2,Co-4)were six-coordinated and adopted an octahedral geometry configuration.Catalytic evaluation of cobalt complexes demonstrated that Co-4 exhibited higher activity than the other three cobalt complexes.This system could provide a series of corresponding imine products with good functional groups compatibility and high yields.Especially,the use of phosphine-free and inexpensive cobalt complexes,along with readily accessible N,O-bidentate ligands featuring N-oxide moieties,offers significant advantages for this reaction.展开更多
Late-stage functionalization is an attractive strategy that allows chemists to bypass lengthy synthetic processes,facilitating the rapid generation of drug analogs with potentially enhanced pharmacokinetic and pharmac...Late-stage functionalization is an attractive strategy that allows chemists to bypass lengthy synthetic processes,facilitating the rapid generation of drug analogs with potentially enhanced pharmacokinetic and pharmacological properties.This study describes a novel approach for cross-dehydrogenative oxyalkylation,leveraging a unique g-ray-enabled photoredox process to generate oxyalkyl radicals,followed by a Minisci-type addition in an aqueous solution.The metal-and oxidant-free aqueous conditions,coupled with excellent functional group compatibility,establish this method as a versatile protocol for the late-stage oxyalkylation of unprotected,structurally complex drug molecules.Notably,this method demonstrated improved pharmacokinetics in hydroxymethylated fibroblast activation protein inhibitor(FAPI)molecules,highlighting its potential to accelerate drug discovery efforts.展开更多
The development of efficient processes allowing rapid access to complex chiral molecules from easily available alkenes is a long-term pursuit in the synthetic chemistry community.Transition metal-catalyzed asymmetric ...The development of efficient processes allowing rapid access to complex chiral molecules from easily available alkenes is a long-term pursuit in the synthetic chemistry community.Transition metal-catalyzed asymmetric functionalization of allylic C–H bond represents a unique alternative toward this goal.However,enantioselective dehydrogenative transformation of olefins to value-added optically enriched molecules remains yet to be discovered.Here,we report a highly enantioselective dehydrogenative dienylation of imines with unactivatedα-alkenes driven by the synergistic action of palladium complex and carboxylic acid.Chiral phosphoramidite ligands turned out to be superior in modulating the performance of palladium autotandem catalysis and allowed a broad range ofα-alkenes and imines to be transformed into chiral dienylamines.Mechanistic studies suggest that the dienes could be in situ generated fromα-alkenes through a palladium(0)-mediated dehydrogenative process in the presence of excess benzoquinone oxidants,and then participated in the Pd-chiral phosphoramidite-catalyzed intermolecular vinylogous-type addition to the imines activated by the carboxylic acid co-catalyst.Notably,the secondβ-H elimination occurring in the dienylation event might be the turnover-limiting step.展开更多
Photocatalytic dehydrogenative homocoupling of benzyl derivatives is a green and sustainable strategy for the direct construction of C(sp^(3))–C(sp^(3))bonds.However,the efficiency of these reactions is significantly...Photocatalytic dehydrogenative homocoupling of benzyl derivatives is a green and sustainable strategy for the direct construction of C(sp^(3))–C(sp^(3))bonds.However,the efficiency of these reactions is significantly hindered by the poor surface kinetics of the hydrogen evolution reaction(HER)and severe charge recombination.Herein,we demonstrate that the electrostatic self-assembly of MoS_(2) colloids on CdS nanosheets(MoS_(2)/CdS)can efficiently capture photogenerated electrons to drive H^(+) reduction,owing to their intrinsic excellent catalytic ability for HER and their strong electron-sink effect for charge separation.This,in turn,facilitates the migration of photogenerated holes from the bulk to the surface,enabling more holes to initiate the oxidative cleavage of C–H bonds in benzyl derivatives,such as cumene.More importantly,MoS_(2) colloids,with Mo atoms sandwiched between two sulfur layers,exhibit much lower interaction with produced·C(CH_(3))_(2) Ph radicals compared to conventional HER cocatalysts,such as noble or transition metal co-catalysts.This facilitates the departure of the·C(CH_(3))_(2) Ph radicals for C(sp^(3))–C(sp^(3))homocoupling reactions,thus enhancing selectivity toward bicummyl.This work presents an efficient,green,and cost-effective strategy for the dehydrogenative homocoupling of benzyl derivatives to construct C(sp^(3))–C(sp^(3))bonds under mild conditions.展开更多
A highly efficient photocatalytic dehydrogenative coupling(PDC)of amines to prepare value-added imines has been developed under the mild conditions.A complete conversion of benzylamine with a 99%selectivity of Nbenzyl...A highly efficient photocatalytic dehydrogenative coupling(PDC)of amines to prepare value-added imines has been developed under the mild conditions.A complete conversion of benzylamine with a 99%selectivity of Nbenzylidenebenzylamine could be obtained using the 2%Pt@g-C_(3)N_(4)as photocatalyst in the absence of hydrogen acceptor at room temperature.Moreover,the relationship between the physical properties of different photocatalysts and their activities has been discussed according to the characterization results of the XRD,BET,SEM,TEM,and XPS techniques.Next,the PDC of different amines have been further investigated,where ca.70.2%-99.0%yields of corresponding imines were attained.Finally,based on the experimental results and heterogeneous catalytic principle,a possible reaction mechanism for the PDC of benzylamine is proposed.展开更多
A hydrogen storage system was developed via heterogeneous catalysis,employing the dehydrogenative coupling of methanol and N,N′-dimethylethylenediamine to efficiently produce high-purity H_(2).In this process,the Cu/...A hydrogen storage system was developed via heterogeneous catalysis,employing the dehydrogenative coupling of methanol and N,N′-dimethylethylenediamine to efficiently produce high-purity H_(2).In this process,the Cu/ZnO/Al_(2)O_(3) catalyst displayed superior activity in hydrogen production,with Cu+identified as the major active site through comprehensive characterization.展开更多
Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make ...Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make this transformation environmentally benign.Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make this transformation environmentally benign.展开更多
The l2 catalyzed highly selective oxidatve condensation of cydohexenones and alcohols for the synthesis of aryl atkyl ethers has been described. DMSO is employed as the mild terminal oxidant. This novel methodology of...The l2 catalyzed highly selective oxidatve condensation of cydohexenones and alcohols for the synthesis of aryl atkyl ethers has been described. DMSO is employed as the mild terminal oxidant. This novel methodology offers a metal-free reaction condition, operational simplicity and broad substrate scope to afford valuable products from inexpensive reagents. Various meta-substituted aromatic ethers which are hardly synthesized from the reported methods requiring meta-substituted phenols, are efficiently prepared by the present protocol.展开更多
Metal catalyzed olefin hydrosilylation and metal mediated olefin polymerization are both of great academic and industrial importance, In this article, these two aspects are combined to prepare silicon- functionalized ...Metal catalyzed olefin hydrosilylation and metal mediated olefin polymerization are both of great academic and industrial importance, In this article, these two aspects are combined to prepare silicon- functionalized polyolefin materials, First, pyridine-diimine cobalt-catalyzed dehydrogenative silylations of various terminal olefins with alkylsilanes lead to the formation of a variety of allylsilanes at high yields, Then, the allylsilanes are copolymerized with ethylene using an α-diimine nickel catalyst, leading to the formation of branched polyolefins with high molecular weight and moderate comonomer incorporation. This subsequent catalytic process is an efficient strategy for the synthesis of silicon-functionalized polyolefins using widely available and inexpensive starting materials.展开更多
Dual-active sites(DASs)catalysts have positive potential applications in broad fields because of their specific active sites and synergistic catalytic effects.Therefore,the controllable synthesis and finely regulating...Dual-active sites(DASs)catalysts have positive potential applications in broad fields because of their specific active sites and synergistic catalytic effects.Therefore,the controllable synthesis and finely regulating the activity of such catalysts has become a hot research area for now.In this work,we developed a pyrolysis-etching-hydrogen activation strategy to prepare the DASs catalysts involving single-atom Cu and B on N-doped porous carbon material(Cu_(1)-B/NPC).Numerous systematic characterization and density functional theoretical(DFT)calculation results showed that the Cu and B existed as Cu-N4 porphyrinlike unit and B-N_(3)unit in the obtained catalyst.DFT calculations further revealed that single-atom Cu and B sites were linked by bridging N atoms to form the Cu_(1)-B-N6 dual-sites.The Cu_(1)-B/NPC catalyst was more effective than the single-active site catalysts with B-N_(3)sites in NPC(B/NPC)and Cu-N4 porphyrin-like sites in NPC(Cu_(1)/NPC),respectively,for the dehydrogenative coupling of dimethylphenylsilane(DiMPSH)with various alcohols,performing the great activity(>99%)and selectivity(>99%).The catalytic performances of the Cu_(1)-B/NPC catalyst remained nearly unchanged after five cycles,also indicating its outstanding recyclability.DFT calculations showed that the Cu_(1)-B-N6 dual-sites exhibited the lowest energy profile on the potential energy surface than that of sole B-N_(3)and Cu-N4 porphyrin-like sites.Furthermore,the rate-limiting step of dehydrogenation of DiMPSH on Cu_(1)-B-N6 dual-sites also showed a much lower activation energy than the other two single sites.Benefitting from the superiority of the Cu_(1)-B-N6 dual-sites,the Cu_(1)-B/NPC catalyst can also be used for CO_(2)electroreduction to produce syngas.Thus,DASs catalysts are promising to achieve multifunctional catalytic properties and have aroused positive attention in the field of catalysis.展开更多
Lactic acid and otherα-hydroxycarboxylic acids(α-HCAs)play crucial roles in various applications.Synthesizingα-HCAs from biomass platform feedstocks such as ethylene glycol(EG)and primary alcohols is novel and attr...Lactic acid and otherα-hydroxycarboxylic acids(α-HCAs)play crucial roles in various applications.Synthesizingα-HCAs from biomass platform feedstocks such as ethylene glycol(EG)and primary alcohols is novel and attractive.It was reported that the dehydrogenative cross-coupling of EG and primary alcohols can be achieved via homogeneous catalysis.Herein,we report a heterogeneous catalytic strategy to produce a series ofα-HCAs through the same reaction pathway.Impressive catalytic activity and selectivity were achieved using various metals(Ru,Ir,Pt and Pd)supported on the nanodiamond-graphene(ND@G),with Ru exhibiting the best performance.This universally applicable process enables the easy synthesis of gram-scaleα-HCAs,providing a straightforward and compelling C–C bond cross-coupling strategy for the utilization of alcohols derived from biomass feedstocks.展开更多
Herein,we report the multi-metal atomic catalysts for solid-state dehydrogenation of MgH_(2).It aims to reveal the multi-element synergy in catalysts for solid-state hydrogen storage.The kinetic measurements and fitti...Herein,we report the multi-metal atomic catalysts for solid-state dehydrogenation of MgH_(2).It aims to reveal the multi-element synergy in catalysts for solid-state hydrogen storage.The kinetic measurements and fitting reveal two mechanisms:one shows a maximum rate at the early stage,such as V and Cr;the other needs a temperature-sensitive preparation time for its maximum rate,such as Ni.The combina-tion of two catalyst components demonstrates the best kinetics:V and Cr boost the initial dehydrogena-tion,and Ni benefits the further hydrogen transfer which alleviates the rate of decay.This work provides guidelines for the design of multi-element doped catalysts for MgH_(2) dehydrogenation.展开更多
基金support from the National Key R&D Program of China(2021YFA1501700)National Natural Science Foundation of China(22425012,22293013)+3 种基金the Shanghai Sailing Program(24YF2756700)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0610000,XDB1180000)CAS Project for Young Scientists in Basic Research(YSBR-O94)Science and Technology Commission of Shanghai Municipality(23JC1404400).
文摘Catalytic dehydrogenative aromatization(CDA)has emerged as a powerful strategy for the synthesis of substituted phenols.However,most of the known CDA methods suffer from limited functional group compatibility due to the use of strong oxidants,reductants,or bases.Herein,we report a(cis-P_(2)Cl)Ir-catalyzed CDA reaction enabled by transfer dehydrogenation(TD).This catalytic system is effective for CDA of both cyclohexanone and cyclohexanol derivatives and demonstrates excellent tolerance toward a variety of functional groups,including readily oxidizable electron-rich heterocycles.DFT studies further reveal that the(cis-P_(2)Cl)Ir catalyst is thermodynamically disfavored for the formation of a potential out-of-cycle catalyst species,iridium phenoxyl hydride complex,via oxidative addition of the phenol O–H bond,thereby preventing catalyst inhibition observed in the previously reported TD system.
基金funding supports from the National Natural Science Foundation of China(Nos.21732002,22061007,22071036,and 22207022)Frontiers Science Center for Asymmetric Synthesis and Medicinal Molecules,National Natural Science Fund for Excellent Young Scientists Fund Program(Overseas),the starting grant of Guizhou University[No.(2022)47)]+10 种基金Department of Education,Guizhou Province[Qianjiaohe KY No.(2020)004]The 10 Talent Plan(Shicengci)of Guizhou Province(No.[2016]5649)Science and Technology Department of Guizhou Province(Nos.[Qiankehe-jichu-ZK[2022]zhongdian024],[2018]2802,[2019]1020,QKHJC-ZK[2022]-455)Department of Education of Guizhou Province(No.QJJ(2022)205)Program of Introducing Talents of Discipline to Universities of China(111 Program,No.D20023)at Guizhou UniversitySingapore National Research Foundation under its NRF Investigatorship(No.NRF-NRFI2016–06)Competitive Research Program(No.NRF-CRP22–2019–0002)Ministry of Education,Singapore,under its MOE Ac RF Tier 1 Award(Nos.RG7/20,RG70/21)MOE AcRF Tier 2(No.MOE2019-T2–2–117)MOE AcRF Tier 3 Award(No.MOE2018-T3–1–003)a Chair Professorship Grant,and Nanyang Technological University。
文摘Enones are widely explored in synthetic chemistry as fundamental building blocks for a wide range of reactions and exhibit intriguing biological activities that are pivotal for drug discovery.The development of synthetic strategies for highly efficient preparation of enones thereby receives intense attention,in particular through the transition metal-catalyzed coupling reactions.Here,we describe a carbene-catalyzed cross dehydrogenative coupling(CDC)reaction that enables effective assembly of simple aldehydes and alkenes to afford a diverse set of enone derivatives.Mechanistically,the in situ generated aryl radical is pivotal to“activate”the alkene by forming an allyl radical through intermolecular hydrogen atom transfer(HAT)pathway and thus forging the carbon-carbon bond formation with aldehyde as the acyl synthon.Notably,our method represents the first example on the enone synthesis through coupling of“non-functionalized”aldehydes and alkenes as coupling partners,and offers a distinct organocatalytic pathway to the transition metal-catalyzed coupling transformations.
基金supported by the National Science Foundation of China(21776268,21721004,22108274 and 22378383)“Transformational Technologies for Clean Energy and Demonstration”,Strategic Priority Research Program of the Chinese Academy of Sciences,(XDA 21060200)support provided by Shanxi Yanchang Petroleum(Group)Co.,Ltd.(yc-hw-2022ky-02).
文摘Exploring stable and robust catalysts to replace the current toxic CuCr based catalysts for dehydrogenative coupling of ethanol to ethyl acetate is a challenging but promising task.Herein,novel NiIn based catalysts were developed by tailoring Ni catalysts with Indium(In)for this reaction.Over the optimal Ni0.1Zn0.7Al0.3InOx catalyst,the ethyl acetate selectivity reached 90.1%at 46.2%ethanol conversion under the conditions of 548 K and a weight hourly space velocity of 1.9 h^(-1)in the 370 h time on stream.Moreover,the ethyl acetate productivity surpassed 1.1 g_(ethyl acetate)g_(catalyst)^(-1)h^(-1),,one of the best performance in current works.According to catalyst characterizations and conditional experiments,the active sites for dehydrogenative coupling of ethanol to ethyl acetate were proved to be Ni4In alloys.The presence of In tailored the chemical properties of Ni,and subsequently inhibited the C-C cracking and/or condensation reactions during ethanol conversions.Over Ni4In alloy sites,ethanol was dehydrogenated into acetaldehyde,and then transformed into acetyl species with the removal of H atoms.Finally,the coupling between acetyl species and surface-abundant ethoxyde species into ethyl acetate was achieved,affording a high ethyl acetate selectivity and catalyst stability.
文摘An environmentally friendly method for the synthesis of 3‐organylselenyl quinolones through theelectrochemical cross‐dehydrogenative coupling of 4‐quinolones and diorganyl diselenides wasdeveloped.As a green,atom economic and self‐separating process,the present reaction requiresneither external oxidants nor electrolytes,forming a recyclable catalytic system.
文摘At atmospheric pressure and ambient temperature, pulse corona induced plasma was used as a new method for dehydrogenative coupling of methane. The synergism of plasma and catalyst on dehydrogenative coupling of methane was investigated. Experimental results have revealed that the synergism does exist, when positive corona within a suitable power range and an intermediate pulse repetition frequency (PRF) for a loaded 7-Mn2O3/7-A12O3 catalyst were chosen. In respect to the mechanism approach, a tentative model for general pathway was proposed to explain the role of plasma and catalyst partaking in the process of methane decomposition and C2 products formation.
基金financially supported by the National Natural Science Foundation of China(Nos.22061027 and 22261034)。
文摘Preparation of chemically recyclable polyesters by ring-opening polymerization(ROP)has made a considerable progress over the past few years.However,this method involves cumbersome synthesis and minimal functional diversity of cyclic monomers.Therefore,it is of great significance to develop novel polymerization methods for direct polymerization of commercially available monomers to prepare recyclable polyesters with versatile functionalities.In present work,we report dehydrogenative copolymerization of commercialα,ω-diols to afford high molecular weight chemically recyclable aliphatic copolyesters(65.7 kg·mol^(-1))by using commercially available Milstein catalyst precursor.The thermal properties of the obtained copolymers could be finely tuned by simply adjusting the feeding ratio of two monomers.The incorporation of aliphatic or aromatic rings into polyester mainchain via copolymerization of 1,10-decanediol with 1,4-cyclohexanedimethanol and 1,4-benzenedimethanol could significantly improve the thermal properties of the resulting copolymers.More importantly,the obtained copolyesters were able to completely depolymerize back to original diols via hydrogenation by the same catalyst in solvent-free and mild conditions,thus offering a green and cost-effective route toward the preparation of widely used polyesters.
基金Financial support by National Key Research and Development Program of China(No.2018YFC0310900)the National Natural Science Foundation of China(Nos.21472087,21532002,21901112,21778031,21761142001)Jiangsu Provincial Department of Science and Technology(No.BK20190277)is greatly appreciated。
文摘An intramolecular dehydrogenative homo-and hetero-coupling of phenols has been successfully developed for quick preparation of enantiopure axial diphenols under mild Cu(Ⅱ)-mediated conditions,using((4 S,5 S)-2,2-dimethyl-1,3-dioxolane-4,5-diyl)dimethanol as the chiral auxiliary.The commercially available(R)-α-met hylbenzy la mine was identified as the best amine ligand for Cu(Ⅱ) in the reactions.A variety of homo/hetero bis-dihydroxylbenzoate substrates were examined,affording the corresponding axially chiral diphenols with satis factory to excellent diastereomeric ratios,and a representative scalable preparation was also attempted.A formal synthesis of natural product(+)-deoxyschizandrin has been achieved in this work using one axially chiral diphenol as the synthetic intermediate.
基金supported by the Japan Society for the Promotion of Science KAKENHI(No.JSPS,17H03458)。
文摘In this review,development of supported catalysts for the dehydrogenative synthesis of benzimidazoles from primary alcohols and 1,2-phenyIenediamine derivatives is briefly summarized.Among them,titania-supported iridium catalysts showed excellent activities under mild reaction conditions.Remarkably,the low-temperature activity of iridium catalyst was significantly affected by titania supports,and the reaction of 1,2-phenylenediamine and benzyl alcohol in the presence of rutilesupported catalysts proceeded smoothly at 100℃to give 2-phenylbenzimidazole in high yields of up to 88%,On the other hand,catalysts supported on anatase generally showed poor activity at 100℃.A significant relationship between CO uptake and the activity of titania-supported catalysts has been reported,indicating that well-reduced iridium species on rutile would be responsible for the predominant catalytic activity.The present results suggest the importance of the selection of suitable titania supports for the iridium catalysts.
基金supported by Fundamental Research Program of Shanxi Province(No.201901D111276)Postgraduate Education Innovation Program of Shanxi Province(Nos.2024KY458,2024JG104).
文摘The transition metal-catalyzed acceptorless dehydrogenative coupling of alcohols and amines is one of the attractive and important strategies for the construction of C=N bonds from the perspective of environmental friendliness and economy.Herein,we report the synthesis of four novel phosphine-free cobalt(II)complexes(Co-1—Co-4)with N,O-bidentate ligands incorporating N-oxide units and their catalytic activity in acceptorless dehydrogenative coupling of benzylic alcohols and aryl amines.X-ray diffraction analyses revealed that the central cobalt atoms in three of the cobalt complexes(Co-1,Co-2,Co-4)were six-coordinated and adopted an octahedral geometry configuration.Catalytic evaluation of cobalt complexes demonstrated that Co-4 exhibited higher activity than the other three cobalt complexes.This system could provide a series of corresponding imine products with good functional groups compatibility and high yields.Especially,the use of phosphine-free and inexpensive cobalt complexes,along with readily accessible N,O-bidentate ligands featuring N-oxide moieties,offers significant advantages for this reaction.
基金funded by the Ministry of Science and Technology of the People’s Republic of China(2021YFA1601400)the National Natural Science Foundation of China(22225603 and 22441051)the New Cornerstone Science Foundation(The XPLORER PRIZE)and Changping Laboratory to Z.L.,and the National Nature Science Foundation of China(22306005)to B.-S.M.
文摘Late-stage functionalization is an attractive strategy that allows chemists to bypass lengthy synthetic processes,facilitating the rapid generation of drug analogs with potentially enhanced pharmacokinetic and pharmacological properties.This study describes a novel approach for cross-dehydrogenative oxyalkylation,leveraging a unique g-ray-enabled photoredox process to generate oxyalkyl radicals,followed by a Minisci-type addition in an aqueous solution.The metal-and oxidant-free aqueous conditions,coupled with excellent functional group compatibility,establish this method as a versatile protocol for the late-stage oxyalkylation of unprotected,structurally complex drug molecules.Notably,this method demonstrated improved pharmacokinetics in hydroxymethylated fibroblast activation protein inhibitor(FAPI)molecules,highlighting its potential to accelerate drug discovery efforts.
基金supported by the National Key R&D Program of China(2021YFA1500100)the National Natural Science Foundation of China(22188101,22322109,22171254)+1 种基金the Youth Innovation Promotion Association,Chinese Academy of Sciences(2020448)the Start-up Research Fund from the University of Science and Technology of China(KY2060000216)。
文摘The development of efficient processes allowing rapid access to complex chiral molecules from easily available alkenes is a long-term pursuit in the synthetic chemistry community.Transition metal-catalyzed asymmetric functionalization of allylic C–H bond represents a unique alternative toward this goal.However,enantioselective dehydrogenative transformation of olefins to value-added optically enriched molecules remains yet to be discovered.Here,we report a highly enantioselective dehydrogenative dienylation of imines with unactivatedα-alkenes driven by the synergistic action of palladium complex and carboxylic acid.Chiral phosphoramidite ligands turned out to be superior in modulating the performance of palladium autotandem catalysis and allowed a broad range ofα-alkenes and imines to be transformed into chiral dienylamines.Mechanistic studies suggest that the dienes could be in situ generated fromα-alkenes through a palladium(0)-mediated dehydrogenative process in the presence of excess benzoquinone oxidants,and then participated in the Pd-chiral phosphoramidite-catalyzed intermolecular vinylogous-type addition to the imines activated by the carboxylic acid co-catalyst.Notably,the secondβ-H elimination occurring in the dienylation event might be the turnover-limiting step.
基金financial support from the National Natural Science Foundation of China(NSFC,Nos.22372036,U24A20567,and 21972022)Natural Science Foundation of Fujian Province(No.2024HZ027004)+4 种基金Natural Science Foundation of Jiangxi Province(Nos.20252BAC240721 and 20232BAB213014)the 111 Project(No.D16008)Program of Jiangxi Academy of Sciences(No.2024TJPT003)Jiangxi Carbon Neutralization Research Center(No.2023YSTZX01)Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment(No.SKLPEE-KF202303),Fuzhou University.
文摘Photocatalytic dehydrogenative homocoupling of benzyl derivatives is a green and sustainable strategy for the direct construction of C(sp^(3))–C(sp^(3))bonds.However,the efficiency of these reactions is significantly hindered by the poor surface kinetics of the hydrogen evolution reaction(HER)and severe charge recombination.Herein,we demonstrate that the electrostatic self-assembly of MoS_(2) colloids on CdS nanosheets(MoS_(2)/CdS)can efficiently capture photogenerated electrons to drive H^(+) reduction,owing to their intrinsic excellent catalytic ability for HER and their strong electron-sink effect for charge separation.This,in turn,facilitates the migration of photogenerated holes from the bulk to the surface,enabling more holes to initiate the oxidative cleavage of C–H bonds in benzyl derivatives,such as cumene.More importantly,MoS_(2) colloids,with Mo atoms sandwiched between two sulfur layers,exhibit much lower interaction with produced·C(CH_(3))_(2) Ph radicals compared to conventional HER cocatalysts,such as noble or transition metal co-catalysts.This facilitates the departure of the·C(CH_(3))_(2) Ph radicals for C(sp^(3))–C(sp^(3))homocoupling reactions,thus enhancing selectivity toward bicummyl.This work presents an efficient,green,and cost-effective strategy for the dehydrogenative homocoupling of benzyl derivatives to construct C(sp^(3))–C(sp^(3))bonds under mild conditions.
基金supported by the National Natural Science Foundation of China(No.21878235).
文摘A highly efficient photocatalytic dehydrogenative coupling(PDC)of amines to prepare value-added imines has been developed under the mild conditions.A complete conversion of benzylamine with a 99%selectivity of Nbenzylidenebenzylamine could be obtained using the 2%Pt@g-C_(3)N_(4)as photocatalyst in the absence of hydrogen acceptor at room temperature.Moreover,the relationship between the physical properties of different photocatalysts and their activities has been discussed according to the characterization results of the XRD,BET,SEM,TEM,and XPS techniques.Next,the PDC of different amines have been further investigated,where ca.70.2%-99.0%yields of corresponding imines were attained.Finally,based on the experimental results and heterogeneous catalytic principle,a possible reaction mechanism for the PDC of benzylamine is proposed.
基金supported by the National Key R&D Program of China(2021YFA1501100)the National Natural Science Foundation of China(22005007)+1 种基金the New Cornerstone Science Foundation,and Liaoning Binhai Laboratory Project(LBLF-202306)the Tencent Foundation through the XPLORER PRIZE.
文摘A hydrogen storage system was developed via heterogeneous catalysis,employing the dehydrogenative coupling of methanol and N,N′-dimethylethylenediamine to efficiently produce high-purity H_(2).In this process,the Cu/ZnO/Al_(2)O_(3) catalyst displayed superior activity in hydrogen production,with Cu+identified as the major active site through comprehensive characterization.
基金supported by Peking University,the National Natural Science Foundation of China(20872003)National Basic Research Program of China(973 program)(2009CB825300)
文摘Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make this transformation environmentally benign.Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make this transformation environmentally benign.
基金Acknowledgement We thank the National Natural Science Foundation of China （Nos. 21325206, 21632001, 21772002）, National Basic Research Program of China （973 Program） （No. 2015CB856600）, National Young Top-notch Talent Support Program, and Peking University Health Science Center （No. BMU20160S41）for financial support of this work. We thank Xiaojing Wen in this group for reproducing the results of 3fa and 3na.
文摘The l2 catalyzed highly selective oxidatve condensation of cydohexenones and alcohols for the synthesis of aryl atkyl ethers has been described. DMSO is employed as the mild terminal oxidant. This novel methodology offers a metal-free reaction condition, operational simplicity and broad substrate scope to afford valuable products from inexpensive reagents. Various meta-substituted aromatic ethers which are hardly synthesized from the reported methods requiring meta-substituted phenols, are efficiently prepared by the present protocol.
基金supported by the National Natural Science Foundation of China(21690071 and 51522306)
文摘Metal catalyzed olefin hydrosilylation and metal mediated olefin polymerization are both of great academic and industrial importance, In this article, these two aspects are combined to prepare silicon- functionalized polyolefin materials, First, pyridine-diimine cobalt-catalyzed dehydrogenative silylations of various terminal olefins with alkylsilanes lead to the formation of a variety of allylsilanes at high yields, Then, the allylsilanes are copolymerized with ethylene using an α-diimine nickel catalyst, leading to the formation of branched polyolefins with high molecular weight and moderate comonomer incorporation. This subsequent catalytic process is an efficient strategy for the synthesis of silicon-functionalized polyolefins using widely available and inexpensive starting materials.
基金supported by the National Natural Science Foundation of China(Nos.51902003,22002085,21771003,21501004)the University Synergy Innovation Program of Anhui Province(No.GXXT-2021-020)+4 种基金the Anhui Province Natural Science Foundation(Nos.2108085QB71 and 2008085QB53)the Natural Science Research Project of Anhui Province Education Department(No.KJ2019A0581)the Open Project of Key Laboratory of Metallurgical Emission Reduction&Resources Recycling of Ministry of Education(No.JKF21-03)the Open Foundation of Anhui Laboratory of Clean Catalytic Engineering(No.LCCE-01)the Open Research Funds of Jiangxi Province Engineering Research Center of Ecological Chemical Industry(STKF2109).
文摘Dual-active sites(DASs)catalysts have positive potential applications in broad fields because of their specific active sites and synergistic catalytic effects.Therefore,the controllable synthesis and finely regulating the activity of such catalysts has become a hot research area for now.In this work,we developed a pyrolysis-etching-hydrogen activation strategy to prepare the DASs catalysts involving single-atom Cu and B on N-doped porous carbon material(Cu_(1)-B/NPC).Numerous systematic characterization and density functional theoretical(DFT)calculation results showed that the Cu and B existed as Cu-N4 porphyrinlike unit and B-N_(3)unit in the obtained catalyst.DFT calculations further revealed that single-atom Cu and B sites were linked by bridging N atoms to form the Cu_(1)-B-N6 dual-sites.The Cu_(1)-B/NPC catalyst was more effective than the single-active site catalysts with B-N_(3)sites in NPC(B/NPC)and Cu-N4 porphyrin-like sites in NPC(Cu_(1)/NPC),respectively,for the dehydrogenative coupling of dimethylphenylsilane(DiMPSH)with various alcohols,performing the great activity(>99%)and selectivity(>99%).The catalytic performances of the Cu_(1)-B/NPC catalyst remained nearly unchanged after five cycles,also indicating its outstanding recyclability.DFT calculations showed that the Cu_(1)-B-N6 dual-sites exhibited the lowest energy profile on the potential energy surface than that of sole B-N_(3)and Cu-N4 porphyrin-like sites.Furthermore,the rate-limiting step of dehydrogenation of DiMPSH on Cu_(1)-B-N6 dual-sites also showed a much lower activation energy than the other two single sites.Benefitting from the superiority of the Cu_(1)-B-N6 dual-sites,the Cu_(1)-B/NPC catalyst can also be used for CO_(2)electroreduction to produce syngas.Thus,DASs catalysts are promising to achieve multifunctional catalytic properties and have aroused positive attention in the field of catalysis.
基金financial support from the National Key R&D Program of China(2022YFA1504800)the Natural Science Foundation of China(22005007,21725301,22232001)+3 种基金China National Petroleum Corporation-Peking University Strategic Cooperation Project of Fundamental Researchthe New Cornerstone Science Foundationsupport from the Beijing Outstanding Young Scientist Program(BJJWZYJH01201914430039)support from the Tencent Foundation through the XPLORER PRIZE。
文摘Lactic acid and otherα-hydroxycarboxylic acids(α-HCAs)play crucial roles in various applications.Synthesizingα-HCAs from biomass platform feedstocks such as ethylene glycol(EG)and primary alcohols is novel and attractive.It was reported that the dehydrogenative cross-coupling of EG and primary alcohols can be achieved via homogeneous catalysis.Herein,we report a heterogeneous catalytic strategy to produce a series ofα-HCAs through the same reaction pathway.Impressive catalytic activity and selectivity were achieved using various metals(Ru,Ir,Pt and Pd)supported on the nanodiamond-graphene(ND@G),with Ru exhibiting the best performance.This universally applicable process enables the easy synthesis of gram-scaleα-HCAs,providing a straightforward and compelling C–C bond cross-coupling strategy for the utilization of alcohols derived from biomass feedstocks.
基金Yijing Wang acknowledges the funding support of the National Key Research and Development Program of China(No.2021YFB4000604)the National Natural Science Foundation of China(No.52271220)+6 种基金the Higher Education Discipline Innovation Project(No.B12015)“the Fundamental Research Funds for the Central Universities”Huaiyu Shao acknowledges the funding support of the Multi-Year Research Grant(MYRG)from the University of Macao(No.MYRG2022-00105-IAPME)the Joint Scientific Research Project Funding by the National Natural Science Foundation of China and the Macao Science and Technology Development Fund(No.0090/2022/AFJ)the Macao Science and Technology Development Fund(FDCT)for funding No.006/2022/ALC of the Macao Centre for Research and Development in Advanced Materials(No.2022-2024)the Natural Science Foundation of Guangdong Province(Grant No.2023A1515010765)the Shenzhen-Hong Kong-Macao Science and Technology Innovation Project(Category C).
文摘Herein,we report the multi-metal atomic catalysts for solid-state dehydrogenation of MgH_(2).It aims to reveal the multi-element synergy in catalysts for solid-state hydrogen storage.The kinetic measurements and fitting reveal two mechanisms:one shows a maximum rate at the early stage,such as V and Cr;the other needs a temperature-sensitive preparation time for its maximum rate,such as Ni.The combina-tion of two catalyst components demonstrates the best kinetics:V and Cr boost the initial dehydrogena-tion,and Ni benefits the further hydrogen transfer which alleviates the rate of decay.This work provides guidelines for the design of multi-element doped catalysts for MgH_(2) dehydrogenation.
