The oxygen evolution reaction(OER) is the cornerstone for many important energy conversion devices, including metal–air battery and water splitting.Herein, an optimized NiFe-based metal–organic framework is develope...The oxygen evolution reaction(OER) is the cornerstone for many important energy conversion devices, including metal–air battery and water splitting.Herein, an optimized NiFe-based metal–organic framework is developed as highly efficient active material for OER. It just needs a low overpotential of 0.31 V to deliver a current density of 10 mA cm-2 with a favorable Tafel slope of 43.7 mV dec-1 in 0.1 M KOH electrolyte for the as-prepared Ni0.75Fe0.25 BDC, which is superior to RuO2. This efficient catalytic performance is due to the introduction of Fe in Ni-based MOFs could benefit the kinetics and charge transfer efficiency, resulting in the optimal activity toward OER. Besides, the obtained active material demonstrates good stability, suggesting the great potential value in sustainable electrochemical energy storage and conversion devices.展开更多
Herein,we report the NHC-Ru catalyst system that realizes the chemo-selective transformation of ketones with methanol.By simply changing the base,a broad range of structurally diverse ketones,could be selectively and ...Herein,we report the NHC-Ru catalyst system that realizes the chemo-selective transformation of ketones with methanol.By simply changing the base,a broad range of structurally diverse ketones,could be selectively and efficiently converted to the correspondingβ-methylated secondary alcohols or secondary alcohols.Remarkably,this catalytic system was very effective for the synthesis of bio-related molecules and deuterated alcohols,as well as the three-component coupling between methyl ketones,primary alcohols,and methanol.The reaction mechanism was further revealed by experiment and DFT mechanistic investigations.展开更多
A photoredox/nickel-catalyzed selective 1,4-arylsulfonation of 1,3-enynes to access structurally diverse sulfone-containing allenes has been established.This radical cascade transformation featured easy manipulation,m...A photoredox/nickel-catalyzed selective 1,4-arylsulfonation of 1,3-enynes to access structurally diverse sulfone-containing allenes has been established.This radical cascade transformation featured easy manipulation,mild conditions,low catalyst loading,broad substrate scope,and large-scale synthesis.The preliminary mechanistic studies indicated a possible radical-relay process enabled by the radical capture of nickel(0)species.展开更多
We disclose the development of the Rh-catalyzed amine-directed remote 5,6-carboamination protocol of pyridines via dual Csp^(2)-H functionalizations.A variety of readily available 2-aminopyridines and 1,2,3-triazoles ...We disclose the development of the Rh-catalyzed amine-directed remote 5,6-carboamination protocol of pyridines via dual Csp^(2)-H functionalizations.A variety of readily available 2-aminopyridines and 1,2,3-triazoles are allowed for coupling cyclization to access polyfunctionalized azaindoles.Mechanistic studies including DFT calculations unveil that relay carbenoidelectrophilic addition to pyridines and the sequential pyridyl Csp^(2)-H amination are involved in this transformation.The postsynthetic utility of this methodology is showcased by versatile and site-selective modification of azaindoles.展开更多
Methanol(CH_(3)OH)is a liquid hydrogen(H_(2))source that effectively releases H_(2) and is convenient for transportation.Traditional thermocatalytic CH_(3)OH reforming reaction is used to produce H_(2),but this proces...Methanol(CH_(3)OH)is a liquid hydrogen(H_(2))source that effectively releases H_(2) and is convenient for transportation.Traditional thermocatalytic CH_(3)OH reforming reaction is used to produce H_(2),but this process needs to undergo high reaction temperature(e.g.,200℃)along with a catalyst and a large amount of carbon dioxide(CO_(2))emission.Although photocatalysis and photothermal catalysis under mild conditions are proposed to replace the traditional thermal catalysis to produce H_(2) from CH_(3)OH,they still inevitably produce CO_(2) emissions that are detrimental to carbon neutrality.Here,we,for the first time,report an ultrafast and highly selective production of H_(2) without any catalysts and no CO_(2) emission from CH_(3)OH by laser bubbling in liquid(LBL)at room temperature and atmospheric pressure.展开更多
Alkenes and alkynes are typical substrates used in atom transfer radical addition(ATRA)reactions,resulting in the formation of vicinal disubstituted products.In this report,vinyldiazoacetates were first developed as t...Alkenes and alkynes are typical substrates used in atom transfer radical addition(ATRA)reactions,resulting in the formation of vicinal disubstituted products.In this report,vinyldiazoacetates were first developed as the radical acceptors in an ATRA reaction of RfI,leading to 1,3-difunctional adducts.The reaction is driven by visible light,without the need for external photocatalysts and additives.A series of control experiments and density functional theory(DFT)calculations indicate the 1,3-addition proceeds via a radical-chain process and the initial Rf radical was generated by homolytic dissociation of a radical pair complex of triplet free vinylcarbene and perfluoroalkyl iodide.After postreaction isomerization,various 1-iodo-3-perfluoroalkyl-alkenes were obtained in good yields with high Z selectivity.The synthetic utility of the ATRA 1,3-adduct was demonstrated by cross-coupling reactions and defluorination of perfluoroalkyl groups.展开更多
Frustrated Lewis pairs（FLPs） emerge as a new type of bifunctional metal-free catalysts for reversible H_2 activation, which is important for the storage and liberation of H_2 or further controllable utilizing chemic...Frustrated Lewis pairs（FLPs） emerge as a new type of bifunctional metal-free catalysts for reversible H_2 activation, which is important for the storage and liberation of H_2 or further controllable utilizing chemical fuels via hydrogenation/dehydrogenation. Herein, a DFT study was conducted to understand the geometric factors and electronic effects of FLPs on reversible H_2 activation. The Lewis base group mainly contributes to the proton attachment, and influences the kinetics of the H_2 activation. The Lewis acid group mainly relates to the hydride attachment, and affects more significantly on the thermodynamics of H_2 activation. The dimer and quenched structure of FLPs also have a degree of influence on the performance of catalyzed H_2 activation. A series of FLPs with para-substituted phenyl derivatives as LA groups were designed and evaluated. The results indicate that the variation of LA groups has significant impact on thermodynamic energy of dihydrogen adducts but insignificant effect on kinetics. Moreover,we found the thermodynamic energy of products has a good linear relationship with Hammett substituent constants. The solvent effect on H_2 activation was also studied, and polar solvent is beneficial for zwitterionic products. These results should provide deeper insight to understand the relation between FLPs structure and reactivity, which is critical for rational design of more efficient FLPs catalysts for reversible H_2 activation.展开更多
A chiral dirhodium complex is an effective and robust catalyst for asymmetric carbene transformations.However,dirhodiumcatalyzed asymmetric ylide interception processes are rare,mainly because of the dissociation of t...A chiral dirhodium complex is an effective and robust catalyst for asymmetric carbene transformations.However,dirhodiumcatalyzed asymmetric ylide interception processes are rare,mainly because of the dissociation of the metal catalyst before the stereo-determining step.Herein,we report a chiral dirhodium(Ⅱ)-catalyzed asymmetric annulation of vinyl diazoesters withα-hydroxyl ketones,which provides an efficient way to form chiral 2,3-dihydropyrans in good yields with excellent diastereoselectivities and enantioselectivities.This article is the first example of the chiral dirhodium complex–controlled asymmetric aldol-type interception of an in situ–formed oxonium ylide.The origin of the high stereoselectivity is well expounded via experimental and computational studies.These generated chiral products exhibit potent antiproliferation activity in three tested cancer cell lines,namely HCT116(colon cancer),A549(lung adenocarcinoma),and SJSA-1(osteosarcoma cancer).展开更多
Electronic tuning by para substitutions was explored to achieve a highly active manganese N-heterocyclic carbene pincer complex for the selective electrocatalytic reduction of CO_(2)to CO.[MnCNC^(OMe)]BF_(4)(L2-Mn)bea...Electronic tuning by para substitutions was explored to achieve a highly active manganese N-heterocyclic carbene pincer complex for the selective electrocatalytic reduction of CO_(2)to CO.[MnCNC^(OMe)]BF_(4)(L2-Mn)bearing an electron-donating group(-OMe)showed high activity with 63×catalytic current enhancement,average Faradaic efficiency of 104%,and a TOF_(max) value of 26,127 s^(-1),which is 127 times higher than that of unsubstituted[MnCNCH]Br(L1-Mn)reported previously.In contrast,the electron-withdrawing group(-COOMe)in[MnCNC^(CO^(OMe))]PF_(6)(L3-Mn)inhibited the electrocatalytic activity.Ambient Brønstic acid,however,suppressed the activity of L2-Mn probably due to the protonation of the-OMe group.These findings indicate a potential electronic tuning strategy to improved manganese N-heterocyclic carbene catalysts for CO_(2)reduction.展开更多
基金supported by The Thousand Talents Plan Foundation of China and Guangdong ProvinceThe 100 Talents Plan Foundation of Sun Yat-sen University (31000-18821107)+2 种基金the Program for Guangdong Introducing Innovative and Enterpreneurial Teams (2017ZT07C069)the NSFC Projects (21573291, 21720102007)the STP Project of Guangzhou (201504010031)
文摘The oxygen evolution reaction(OER) is the cornerstone for many important energy conversion devices, including metal–air battery and water splitting.Herein, an optimized NiFe-based metal–organic framework is developed as highly efficient active material for OER. It just needs a low overpotential of 0.31 V to deliver a current density of 10 mA cm-2 with a favorable Tafel slope of 43.7 mV dec-1 in 0.1 M KOH electrolyte for the as-prepared Ni0.75Fe0.25 BDC, which is superior to RuO2. This efficient catalytic performance is due to the introduction of Fe in Ni-based MOFs could benefit the kinetics and charge transfer efficiency, resulting in the optimal activity toward OER. Besides, the obtained active material demonstrates good stability, suggesting the great potential value in sustainable electrochemical energy storage and conversion devices.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.22002023,21973113,21977019)the Guangdong Natural Science Funds for Distin-guished Young Scholar(No.2015A030306027)+1 种基金the Tip-top Youth Talents of Guangdong special support program(No.20153100042090537)the Fundamental Research Funds for the Central Universities。
文摘Herein,we report the NHC-Ru catalyst system that realizes the chemo-selective transformation of ketones with methanol.By simply changing the base,a broad range of structurally diverse ketones,could be selectively and efficiently converted to the correspondingβ-methylated secondary alcohols or secondary alcohols.Remarkably,this catalytic system was very effective for the synthesis of bio-related molecules and deuterated alcohols,as well as the three-component coupling between methyl ketones,primary alcohols,and methanol.The reaction mechanism was further revealed by experiment and DFT mechanistic investigations.
文摘A photoredox/nickel-catalyzed selective 1,4-arylsulfonation of 1,3-enynes to access structurally diverse sulfone-containing allenes has been established.This radical cascade transformation featured easy manipulation,mild conditions,low catalyst loading,broad substrate scope,and large-scale synthesis.The preliminary mechanistic studies indicated a possible radical-relay process enabled by the radical capture of nickel(0)species.
基金supported by the National Natural Science Foundation of China(22271100,21973113)the Key-Area Research and Development Program of Guangdong Province(2020-B010188001)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2023A1515010070)the China Postdoctoral Science Foundation(2021M701243)。
文摘We disclose the development of the Rh-catalyzed amine-directed remote 5,6-carboamination protocol of pyridines via dual Csp^(2)-H functionalizations.A variety of readily available 2-aminopyridines and 1,2,3-triazoles are allowed for coupling cyclization to access polyfunctionalized azaindoles.Mechanistic studies including DFT calculations unveil that relay carbenoidelectrophilic addition to pyridines and the sequential pyridyl Csp^(2)-H amination are involved in this transformation.The postsynthetic utility of this methodology is showcased by versatile and site-selective modification of azaindoles.
基金The National Natural Science Foundation of China(51832011)the State Key Laboratory of Optoelectronic Materials and Technologies supported this work.
文摘Methanol(CH_(3)OH)is a liquid hydrogen(H_(2))source that effectively releases H_(2) and is convenient for transportation.Traditional thermocatalytic CH_(3)OH reforming reaction is used to produce H_(2),but this process needs to undergo high reaction temperature(e.g.,200℃)along with a catalyst and a large amount of carbon dioxide(CO_(2))emission.Although photocatalysis and photothermal catalysis under mild conditions are proposed to replace the traditional thermal catalysis to produce H_(2) from CH_(3)OH,they still inevitably produce CO_(2) emissions that are detrimental to carbon neutrality.Here,we,for the first time,report an ultrafast and highly selective production of H_(2) without any catalysts and no CO_(2) emission from CH_(3)OH by laser bubbling in liquid(LBL)at room temperature and atmospheric pressure.
基金the National Basic Research Program of China(no.2016YFA0602900)the National Natural Science Foundation of China(nos.21871300,21673301,and 21973113)the NSF of Guangdong Province for Distinguished Young Scholar(nos.2016A030306029 and 20153100042090537).
文摘Alkenes and alkynes are typical substrates used in atom transfer radical addition(ATRA)reactions,resulting in the formation of vicinal disubstituted products.In this report,vinyldiazoacetates were first developed as the radical acceptors in an ATRA reaction of RfI,leading to 1,3-difunctional adducts.The reaction is driven by visible light,without the need for external photocatalysts and additives.A series of control experiments and density functional theory(DFT)calculations indicate the 1,3-addition proceeds via a radical-chain process and the initial Rf radical was generated by homolytic dissociation of a radical pair complex of triplet free vinylcarbene and perfluoroalkyl iodide.After postreaction isomerization,various 1-iodo-3-perfluoroalkyl-alkenes were obtained in good yields with high Z selectivity.The synthetic utility of the ATRA 1,3-adduct was demonstrated by cross-coupling reactions and defluorination of perfluoroalkyl groups.
基金supported by the National Natural Science Foundation of China (Nos. 21502023 and 21473261)the Guangdong Natural Science Funds for Distinguished Young Scholar(No. 2015A030306027)+1 种基金the Guangdong Special Support Plan for High-Level Talent(No. 20153100042090537)supported in part by the high performance grid computing platform of Sun Yat-sen University, the Guangdong Province Key Laboratory of Computational Science, and Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (No. U1501501)
文摘Frustrated Lewis pairs（FLPs） emerge as a new type of bifunctional metal-free catalysts for reversible H_2 activation, which is important for the storage and liberation of H_2 or further controllable utilizing chemical fuels via hydrogenation/dehydrogenation. Herein, a DFT study was conducted to understand the geometric factors and electronic effects of FLPs on reversible H_2 activation. The Lewis base group mainly contributes to the proton attachment, and influences the kinetics of the H_2 activation. The Lewis acid group mainly relates to the hydride attachment, and affects more significantly on the thermodynamics of H_2 activation. The dimer and quenched structure of FLPs also have a degree of influence on the performance of catalyzed H_2 activation. A series of FLPs with para-substituted phenyl derivatives as LA groups were designed and evaluated. The results indicate that the variation of LA groups has significant impact on thermodynamic energy of dihydrogen adducts but insignificant effect on kinetics. Moreover,we found the thermodynamic energy of products has a good linear relationship with Hammett substituent constants. The solvent effect on H_2 activation was also studied, and polar solvent is beneficial for zwitterionic products. These results should provide deeper insight to understand the relation between FLPs structure and reactivity, which is critical for rational design of more efficient FLPs catalysts for reversible H_2 activation.
基金supported by the National Natural Science Foundation of China(22001268,21973113,81973176)the Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery(2019B030301005)+2 种基金the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2016ZT06Y337)the Guangdong Natural Science Fund(2020A1515010614)Key-Area Research and Development Program of Guangdong Province(2022B1111050003)。
文摘A chiral dirhodium complex is an effective and robust catalyst for asymmetric carbene transformations.However,dirhodiumcatalyzed asymmetric ylide interception processes are rare,mainly because of the dissociation of the metal catalyst before the stereo-determining step.Herein,we report a chiral dirhodium(Ⅱ)-catalyzed asymmetric annulation of vinyl diazoesters withα-hydroxyl ketones,which provides an efficient way to form chiral 2,3-dihydropyrans in good yields with excellent diastereoselectivities and enantioselectivities.This article is the first example of the chiral dirhodium complex–controlled asymmetric aldol-type interception of an in situ–formed oxonium ylide.The origin of the high stereoselectivity is well expounded via experimental and computational studies.These generated chiral products exhibit potent antiproliferation activity in three tested cancer cell lines,namely HCT116(colon cancer),A549(lung adenocarcinoma),and SJSA-1(osteosarcoma cancer).
基金supported by the National Natural Science Foundation of China(No.21973113)the Guangdong Natural Science Funds for Distinguished Young Scholar(No.2015A030306027)the Fundamental Research Funds for the Central Universities。
文摘Electronic tuning by para substitutions was explored to achieve a highly active manganese N-heterocyclic carbene pincer complex for the selective electrocatalytic reduction of CO_(2)to CO.[MnCNC^(OMe)]BF_(4)(L2-Mn)bearing an electron-donating group(-OMe)showed high activity with 63×catalytic current enhancement,average Faradaic efficiency of 104%,and a TOF_(max) value of 26,127 s^(-1),which is 127 times higher than that of unsubstituted[MnCNCH]Br(L1-Mn)reported previously.In contrast,the electron-withdrawing group(-COOMe)in[MnCNC^(CO^(OMe))]PF_(6)(L3-Mn)inhibited the electrocatalytic activity.Ambient Brønstic acid,however,suppressed the activity of L2-Mn probably due to the protonation of the-OMe group.These findings indicate a potential electronic tuning strategy to improved manganese N-heterocyclic carbene catalysts for CO_(2)reduction.
