Water oxidation is the key half reaction to achieve full splitting of water to hydrogen and oxygen.Herein,a binuclear complex,[(L^(4-))Co_(2)~Ⅲ(OH)]ClO_(4),was reported as a stable and efficient homogenous catalyst f...Water oxidation is the key half reaction to achieve full splitting of water to hydrogen and oxygen.Herein,a binuclear complex,[(L^(4-))Co_(2)~Ⅲ(OH)]ClO_(4),was reported as a stable and efficient homogenous catalyst for electrocatalytic water oxidation in 0.1 M phosphate buffer(pH 7.0).Cyclic voltammetry experiments indicated that the catalytic process proceed via "one-site catalysis with two-sites oxidation" mechanism in which both two metal sites store the required oxidation equivalents for water oxidation and O-O bond formation occurs by single-site water nucleophilic attack(WNA).展开更多
Reductive deoxygenation of ketones using H_(2) is a highly desirable but also challenging transformation in both chemical synthesis,industrial-scale petroleum and biomass feedstock reforming processes.Herein,we report...Reductive deoxygenation of ketones using H_(2) is a highly desirable but also challenging transformation in both chemical synthesis,industrial-scale petroleum and biomass feedstock reforming processes.Herein,we report a cooperative cobalt/Lewis acid (LA)-catalyzed hydrodeoxygenation of ketones using H_(2) as the reductant.In particular,the newly developed pincer cobalt catalyst possesses dual hydrogenation activities for both ketones and alkenes under the same reaction conditions.This reaction features a broad substrate scope,excellent functional-group compatibility,and potential applicability.展开更多
Direct alkylation with skipped enynes or cyclopropropylacetylenes represents an ideal process for the installation of pentadienyl group in terms of atom- and step-economy.The development of catalytic asymmetric versio...Direct alkylation with skipped enynes or cyclopropropylacetylenes represents an ideal process for the installation of pentadienyl group in terms of atom- and step-economy.The development of catalytic asymmetric versions has been frequently pursued and most of the successes have been achieved with enolizable aldehydes.We herein describe a synergistic chiral primary amine/Pd catalysis for asymmetric α-pentadienylation of β-ketocarbonyls and aldehydes with skipped enynes or cyclopropropylacetylenes.The reaction features the construction of acyclic all-carbon quaternary centers with high enantioselectivity,and good functional group tolerance and scalability.展开更多
Electrostatic interaction, especially electrostatic attraction, usually plays critical roles in controlling the reactivity and selectivity in catalytic transformations;however, the like-charge repulsion, which is ubiq...Electrostatic interaction, especially electrostatic attraction, usually plays critical roles in controlling the reactivity and selectivity in catalytic transformations;however, the like-charge repulsion, which is ubiquitous in physical systems, is rarely applied in reaction control. Herein we disclosed an unexpected like-charge repulsion induced enantio-control mode in primary aminecatalyzed fluorination reactions with 1-fluoro-2,4,6-trimethylpyridinium triflate. The ionic reaction works favorably in both highly polar(methanol) and non-polar(hexane) solvents, a seldom observed phenomenon in asymmetric catalysis. Erying plot analysis showed that an inversion temperature existed in Me OH, which was explained by the solvent-solute cluster model under different temperatures. Density functional theory(DFT) study and energy decomposition analysis(EDA) verified that the likecharge repulsion takes effect in polar solvent methanol, while in nonpolar solvents, the steric repulsion associated with ion-pair was found to be the major effect for the observed enantioselectivity.展开更多
We report herein a visible light-mediated direct deuteration of alkenes with D_(2)O or deuterated methanol(MeOD)using a cobaloxime as a hydrogen/deuterium(H/D)exchange catalyst.The synergistic photoredox/Co catalysis ...We report herein a visible light-mediated direct deuteration of alkenes with D_(2)O or deuterated methanol(MeOD)using a cobaloxime as a hydrogen/deuterium(H/D)exchange catalyst.The synergistic photoredox/Co catalysis enabled facile deuterium(D)-incorporation of a variety of terminal and internal alkenes at either terminal or benzylic positions.We proposed that this process proceeded through a sequence of reversible addition-elimination reactions and fast proton exchange involving Co(III)–H,which was generated in situ by photoreduction.展开更多
We report a molecular trinuclear nickel(TNC-Ni)catalyst for water oxidation that exhibited high catalytic performance and stability under neutral conditions(pH 7).Electrochemical studies disclosed that cooperation amo...We report a molecular trinuclear nickel(TNC-Ni)catalyst for water oxidation that exhibited high catalytic performance and stability under neutral conditions(pH 7).Electrochemical studies disclosed that cooperation among the three nickel sites plays a vital role in both charge accumulation and O-O bond formation.This TNC-Ni catalyst could accomplish 4e−oxidation of water by involving all three nickel sites and the O-O bond formation was triggered by a charge distribution process from 5 to 5_(dp) via proton-coupled electron transfer.展开更多
The precise construction of chiral molecules is a core research area in chemical science and technology.Among the plethora of reported synthetic methods,asymmetric catalysis has emerged as one of the most efficient an...The precise construction of chiral molecules is a core research area in chemical science and technology.Among the plethora of reported synthetic methods,asymmetric catalysis has emerged as one of the most efficient and direct ways to obtain optically pure chiral compounds.This article mainly reviews the recent progress of asymmetric catalysis made by Chinese chemists from the following aspects:the development of new chiral ligands,transition metal-catalyzed asymmetric reactions,asymmetric organocatalytic reactions,and new strategies for asymmetric catalysis.This review does not intend to be comprehensive;only representative examples are selected to highlight the important progress made in this field.Finally,a brief outlook is given on the development of novel chiral ligands/catalysts,new enantioselective reactions,and their applications in chiral drugs and agricultural chemicals.展开更多
The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable c...The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable chemicals,is highly desirable.Herein,we report a novel manganese-catalyzed dehydrogenative cyclization of methanol as a formaldehyde surrogate with a variety of dinucleophiles for facile synthesis of N-heterocycles.The in situ generated formaldehyde via catalytic methanol dehydrogenation can be selectively trapped by diverse dinucleophiles to avoid several possible side reactions.The utilty of this transformation is further highlighted by its successful appliation to the synthesis of 13C-labeled N-heterocycles using 13CH_(3)OH as a readily accessible 13C-isotope reagent.展开更多
Alkenes are versatile compounds that are available on large scales in industry or through chemical synthesis.Selective functionalization of unactivated alkenes in a chemo-,regio-,diastereo-and enantioselective fashion...Alkenes are versatile compounds that are available on large scales in industry or through chemical synthesis.Selective functionalization of unactivated alkenes in a chemo-,regio-,diastereo-and enantioselective fashion is a highly sought-after goal in organic synthesis.Substrate-directed enantioselective functionalization of unactivated alkenes provides an important strategy to achieve this goal.Using a functional group on the alkene substrate as a native coordinating group,a two-point binding mode of the substrate to the metal center enables effective control of regio-;diastereo-and enantioselectivities.Through this strategy,a variety of enantioselective functionalization methods have been developed recently.The recent advances in this area are highlighted here.展开更多
Background and Originality Content Reduction of esters to alcohols is a fundamental transformation in organic chemistry,and is important for the production of a wide range of bulk and fine chemicals.Compared with trad...Background and Originality Content Reduction of esters to alcohols is a fundamental transformation in organic chemistry,and is important for the production of a wide range of bulk and fine chemicals.Compared with traditional approaches using stoichiometric amounts of metal hydride reagents,catalytic hydrogenation represents an environmentally benign and atom economic alternative.展开更多
Herein,we report tunable asymmetric addition and telomerization of butadiene by synergistic chiral primary amine/achiral palladium catalysis.A selection of different achiral phosphine ligand in concert with the chiral...Herein,we report tunable asymmetric addition and telomerization of butadiene by synergistic chiral primary amine/achiral palladium catalysis.A selection of different achiral phosphine ligand in concert with the chiral primary amine-trifluoromethanesulfonic acid(TfOH)conjugates enables both chemo-and enantioselective control of the coupling with butadiene.Bidentate[(oxydi-2,1-phenylene)-bis-(diphenylphosphine)](DPEPhos)ligand led to 1,4-addition adduct whereas monodentate(p-Tol)3P ligand gave the telomerization product.A range ofα-branchedβ-ketoesters and aldehydes could be applied to afford allylation or telomerization products bearing allcarbon quaternary centers at high efficiency and good chemo-,regio-,and stereoselectivities.展开更多
Although fluorobis(phenylsulfonyl)methane(FBSM)and its cyclic analog 2-fluoro-1,3-benzodithiole-1,1,3,3-tetraoxide(FBDT)possess similar physicochemical properties,Shibata et al.found that FBSM failed to undergo nucleo...Although fluorobis(phenylsulfonyl)methane(FBSM)and its cyclic analog 2-fluoro-1,3-benzodithiole-1,1,3,3-tetraoxide(FBDT)possess similar physicochemical properties,Shibata et al.found that FBSM failed to undergo nucleophilic monofluoromethylation of aldehydes regardless of the reaction conditions at-tempted(using various organic and inorganic bases).However,it was later discovered by Hu et al.that the nucleophilic monofluoromethylation could be accomplished by employing lithium hexamethyldisi-lazide(LiHMDS)as a base.Herein,we present an in-depth computational investigation into the intrigu-ing effects of reagent structure and bases on the nucleophilic monofluoromethylation of aldehydes.The computations reveal the 1,4-diazabicyclo[2.2.2]octane(DABCO)catalyzed nucleophilic monofluoromethy-lation of benzaldehyde with acyclic FBSM is a thermodynamically unfavorable process mainly due to the destabilizing O···O lone pair repulsions in FBSM product,whereas such repulsion could be largely avoided in FBDT product because of its constrained five-membered ring structure.Employing LiHMDS as a base can not only facilitate the nucleophilic monofluoromethylation via Li–O interactions but also render the monofluoromethylation of benzaldehyde with FBSM thermodynamically favored.展开更多
Hybrid quantum mechanics/molecular mechanics calculations were performed to elucidate how[Mn^(Ⅲ)porphyrin]^(+X−)-based metal-organic frameworks(MOFs)catalyze the[2+1]cycloisomerization of enynes and why zwitterionic ...Hybrid quantum mechanics/molecular mechanics calculations were performed to elucidate how[Mn^(Ⅲ)porphyrin]^(+X−)-based metal-organic frameworks(MOFs)catalyze the[2+1]cycloisomerization of enynes and why zwitterionic MOFs exhibit strong activity in Lewis acid catalysis.The calculations showed that zwitterionic MOFs have a“pure cationic active center”leading to a concerted nucleophilic attack pathway with lower barriers.In contrast,metals with coordinating anions have reduced electrophilicity,resulting in a stepwise radical-type pathway with much higher barriers.Further calculations showed the nature of catalysis was strongly depended on the charge on the anion ligand.A good linear relationship between the NPA charge and barrier was found,and verified by 73 anions with small derivations,which presents a universal adaptive character for various coordinated anions.展开更多
Summary of main observation and conclusion Electrophilic trifluoromethylthiolation has emerged as an important and efficient methodology for installing the SCF3 moiety onto an array of organic molecules.Due to the low...Summary of main observation and conclusion Electrophilic trifluoromethylthiolation has emerged as an important and efficient methodology for installing the SCF3 moiety onto an array of organic molecules.Due to the low reactivities of trifluoromethylthiolating reagents,these transformations often require activation through an exogenous Lewis/Br0nsted acid.We report herein the quantification of the activation capabilities of Lewis/Br0nsted acids for trifluoromethylthiolating reagents through computing the differenee in trifluoromethylthio cation donor ability(Tt+DA)between the"activated"and"unactivated"reagent.A moderate correlation is found to exist between the activation capability and Lewis acidity.展开更多
Enantioselective oxidative construction of a C(sp^(3))–S bond has been achieved using a chiral primary amine catalyst in the presence of tert-butyl hydroperoxide and a catalytic amount of tetrabutylammonium iodide.Th...Enantioselective oxidative construction of a C(sp^(3))–S bond has been achieved using a chiral primary amine catalyst in the presence of tert-butyl hydroperoxide and a catalytic amount of tetrabutylammonium iodide.The distinctive feature of the current reaction is coupling with nucleophilic sulfur reactants under oxidative conditions.This protocol provides facile access to chiral thioethers bearing S-containing quaternary stereocenters with good chemo-and enantiocontrol.展开更多
Enzymes are the core for biological transformations in nature.Their structures and functions have drawn enormous attention from biologists as well as chemists since last century.The large demand of bioactive molecules...Enzymes are the core for biological transformations in nature.Their structures and functions have drawn enormous attention from biologists as well as chemists since last century.The large demand of bioactive molecules and the pursuit of efficiency and greenness of synthesis have spurred the rapid development of biomimetic chemistry in the past several decades.Biomimetic asymmetric catalysis,mimicking the structures and functions of enzymes,has been recognized as one of the most promising synthetic strategies for the synthesis of valuable chiral compounds.This review summarizes the evolution of asymmetric catalysis inspired by aldolases,vitamin B_(1)/B_(6)-dependent enzymes,NAD(P)H,flavin,hydrogenases,heme oxygenases,nonheme oxygenases,and dinuclear/multinuclear metalloenzymes in aspects of biomimetic design,catalyst development and related catalytic transformations.Those well-established synthetic approaches originating from biological reactions have demonstrated the unique prowess of biomimetic asymmetric catalysis in bridging the gap between bio-catalysis and chemical synthesis.展开更多
The first comprehensive I(Ⅲ)-X(X=F,Br,CN,N3,CF3,etc.)bond dissociation energy(BDE)scales for benziodoxol(on)e-based hypervalent iodine reagents have been developed by virtue of DFT calculations.Excellent correlation ...The first comprehensive I(Ⅲ)-X(X=F,Br,CN,N3,CF3,etc.)bond dissociation energy(BDE)scales for benziodoxol(on)e-based hypervalent iodine reagents have been developed by virtue of DFT calculations.Excellent correlation is observed between the I(Ⅲ)-X BDEs and the X-H BDEs,offering a powerful avenue to quickly estimate the group-transfer ability of a novel benziodoxol(on)e-based hypervalent reagent.展开更多
基金financially supported by the National Natural Science Foundation of China (21933007)。
文摘Water oxidation is the key half reaction to achieve full splitting of water to hydrogen and oxygen.Herein,a binuclear complex,[(L^(4-))Co_(2)~Ⅲ(OH)]ClO_(4),was reported as a stable and efficient homogenous catalyst for electrocatalytic water oxidation in 0.1 M phosphate buffer(pH 7.0).Cyclic voltammetry experiments indicated that the catalytic process proceed via "one-site catalysis with two-sites oxidation" mechanism in which both two metal sites store the required oxidation equivalents for water oxidation and O-O bond formation occurs by single-site water nucleophilic attack(WNA).
基金Financial support from the National Key R&D Program of China(2021YFF0701600)the National Natural Science Foundation of China(22225103)Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs,Shanghai Jiao Tong University is greatlyappreciated.
文摘Reductive deoxygenation of ketones using H_(2) is a highly desirable but also challenging transformation in both chemical synthesis,industrial-scale petroleum and biomass feedstock reforming processes.Herein,we report a cooperative cobalt/Lewis acid (LA)-catalyzed hydrodeoxygenation of ketones using H_(2) as the reductant.In particular,the newly developed pincer cobalt catalyst possesses dual hydrogenation activities for both ketones and alkenes under the same reaction conditions.This reaction features a broad substrate scope,excellent functional-group compatibility,and potential applicability.
基金the Natural Science Foundation of China(21861132003 and 22031006)Tsinghua University Initiative Scientific Research Program for financial support.
文摘Direct alkylation with skipped enynes or cyclopropropylacetylenes represents an ideal process for the installation of pentadienyl group in terms of atom- and step-economy.The development of catalytic asymmetric versions has been frequently pursued and most of the successes have been achieved with enolizable aldehydes.We herein describe a synergistic chiral primary amine/Pd catalysis for asymmetric α-pentadienylation of β-ketocarbonyls and aldehydes with skipped enynes or cyclopropropylacetylenes.The reaction features the construction of acyclic all-carbon quaternary centers with high enantioselectivity,and good functional group tolerance and scalability.
基金supported by the National Natural Science Foundation of China (22373056, 22031006)the Haihe Laboratory of Sustainable Chemical Transformations (YYJC202113)+1 种基金the National Science & Technology Fundamental Resource Investigation Program of China (2018FY201200)supported by the National Program of Top-notch Young Professionals。
文摘Electrostatic interaction, especially electrostatic attraction, usually plays critical roles in controlling the reactivity and selectivity in catalytic transformations;however, the like-charge repulsion, which is ubiquitous in physical systems, is rarely applied in reaction control. Herein we disclosed an unexpected like-charge repulsion induced enantio-control mode in primary aminecatalyzed fluorination reactions with 1-fluoro-2,4,6-trimethylpyridinium triflate. The ionic reaction works favorably in both highly polar(methanol) and non-polar(hexane) solvents, a seldom observed phenomenon in asymmetric catalysis. Erying plot analysis showed that an inversion temperature existed in Me OH, which was explained by the solvent-solute cluster model under different temperatures. Density functional theory(DFT) study and energy decomposition analysis(EDA) verified that the likecharge repulsion takes effect in polar solvent methanol, while in nonpolar solvents, the steric repulsion associated with ion-pair was found to be the major effect for the observed enantioselectivity.
基金the Natural Science Foundation of China(grant nos.91956000,22031006,21861132003),Tsinghua University Initiative Scientific Research Program,and Haihe Laboratory of Sustainable Chemical Transformations for financial support.
文摘We report herein a visible light-mediated direct deuteration of alkenes with D_(2)O or deuterated methanol(MeOD)using a cobaloxime as a hydrogen/deuterium(H/D)exchange catalyst.The synergistic photoredox/Co catalysis enabled facile deuterium(D)-incorporation of a variety of terminal and internal alkenes at either terminal or benzylic positions.We proposed that this process proceeded through a sequence of reversible addition-elimination reactions and fast proton exchange involving Co(III)–H,which was generated in situ by photoreduction.
基金This research is dedicated to the 10th anniversary of the Center of Basic Molecular Science(CBMS)at Tsinghua University.This work was financially supported by the National Science Foundation of China(grant nos.21933007 and 21873031).The authors appreciate the reviewers for their helpful comments.Q.-F.C.thanks Dr.Hai-Fang Li at Tsinghua University for the help on ESI-HRMS measurements.
文摘We report a molecular trinuclear nickel(TNC-Ni)catalyst for water oxidation that exhibited high catalytic performance and stability under neutral conditions(pH 7).Electrochemical studies disclosed that cooperation among the three nickel sites plays a vital role in both charge accumulation and O-O bond formation.This TNC-Ni catalyst could accomplish 4e−oxidation of water by involving all three nickel sites and the O-O bond formation was triggered by a charge distribution process from 5 to 5_(dp) via proton-coupled electron transfer.
基金supported by major research plan“Precise Construction of Multilevel Chiral Substances”of the National Natural Science Foundation of China(grant nos.91956000,92256000,and 92256303).
文摘The precise construction of chiral molecules is a core research area in chemical science and technology.Among the plethora of reported synthetic methods,asymmetric catalysis has emerged as one of the most efficient and direct ways to obtain optically pure chiral compounds.This article mainly reviews the recent progress of asymmetric catalysis made by Chinese chemists from the following aspects:the development of new chiral ligands,transition metal-catalyzed asymmetric reactions,asymmetric organocatalytic reactions,and new strategies for asymmetric catalysis.This review does not intend to be comprehensive;only representative examples are selected to highlight the important progress made in this field.Finally,a brief outlook is given on the development of novel chiral ligands/catalysts,new enantioselective reactions,and their applications in chiral drugs and agricultural chemicals.
基金This project was supported by the National Natural Science Foundation of China(Nos.91845107 and 21822106)the Foundation of the Department of Education of Guangdong Province(2018KZDXM070 and 2021KTSCX140)。
文摘The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable chemicals,is highly desirable.Herein,we report a novel manganese-catalyzed dehydrogenative cyclization of methanol as a formaldehyde surrogate with a variety of dinucleophiles for facile synthesis of N-heterocycles.The in situ generated formaldehyde via catalytic methanol dehydrogenation can be selectively trapped by diverse dinucleophiles to avoid several possible side reactions.The utilty of this transformation is further highlighted by its successful appliation to the synthesis of 13C-labeled N-heterocycles using 13CH_(3)OH as a readily accessible 13C-isotope reagent.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.21672122 and No.91856107),111 Project(B16028).
文摘Alkenes are versatile compounds that are available on large scales in industry or through chemical synthesis.Selective functionalization of unactivated alkenes in a chemo-,regio-,diastereo-and enantioselective fashion is a highly sought-after goal in organic synthesis.Substrate-directed enantioselective functionalization of unactivated alkenes provides an important strategy to achieve this goal.Using a functional group on the alkene substrate as a native coordinating group,a two-point binding mode of the substrate to the metal center enables effective control of regio-;diastereo-and enantioselectivities.Through this strategy,a variety of enantioselective functionalization methods have been developed recently.The recent advances in this area are highlighted here.
基金We are grateful for the financial supports from the National Natural Science Foundation of China(Nos.21822106 and 91845107)the Beijing Municipal Commission of Science and Technology(No.Z 181100005118001).
文摘Background and Originality Content Reduction of esters to alcohols is a fundamental transformation in organic chemistry,and is important for the production of a wide range of bulk and fine chemicals.Compared with traditional approaches using stoichiometric amounts of metal hydride reagents,catalytic hydrogenation represents an environmentally benign and atom economic alternative.
基金the Natural Science Foundation of China(nos.21672217,21861132003,and 22031006)Tsinghua University Initiative Scientific Research Program for financial support.
文摘Herein,we report tunable asymmetric addition and telomerization of butadiene by synergistic chiral primary amine/achiral palladium catalysis.A selection of different achiral phosphine ligand in concert with the chiral primary amine-trifluoromethanesulfonic acid(TfOH)conjugates enables both chemo-and enantioselective control of the coupling with butadiene.Bidentate[(oxydi-2,1-phenylene)-bis-(diphenylphosphine)](DPEPhos)ligand led to 1,4-addition adduct whereas monodentate(p-Tol)3P ligand gave the telomerization product.A range ofα-branchedβ-ketoesters and aldehydes could be applied to afford allylation or telomerization products bearing allcarbon quaternary centers at high efficiency and good chemo-,regio-,and stereoselectivities.
基金supported by the Natural Science Foundation of China(Nos.22122104,21933004 and 21702098).
文摘Although fluorobis(phenylsulfonyl)methane(FBSM)and its cyclic analog 2-fluoro-1,3-benzodithiole-1,1,3,3-tetraoxide(FBDT)possess similar physicochemical properties,Shibata et al.found that FBSM failed to undergo nucleophilic monofluoromethylation of aldehydes regardless of the reaction conditions at-tempted(using various organic and inorganic bases).However,it was later discovered by Hu et al.that the nucleophilic monofluoromethylation could be accomplished by employing lithium hexamethyldisi-lazide(LiHMDS)as a base.Herein,we present an in-depth computational investigation into the intrigu-ing effects of reagent structure and bases on the nucleophilic monofluoromethylation of aldehydes.The computations reveal the 1,4-diazabicyclo[2.2.2]octane(DABCO)catalyzed nucleophilic monofluoromethy-lation of benzaldehyde with acyclic FBSM is a thermodynamically unfavorable process mainly due to the destabilizing O···O lone pair repulsions in FBSM product,whereas such repulsion could be largely avoided in FBDT product because of its constrained five-membered ring structure.Employing LiHMDS as a base can not only facilitate the nucleophilic monofluoromethylation via Li–O interactions but also render the monofluoromethylation of benzaldehyde with FBSM thermodynamically favored.
基金supported by the National Natural Science Foundation of China (Nos. 21822303 21772020 22173083)Program for Science Technology Innovation Talents in Universities of Henan Province (No. 20HASTIT004)the support from the Henan Province Supercomputing Center
文摘Hybrid quantum mechanics/molecular mechanics calculations were performed to elucidate how[Mn^(Ⅲ)porphyrin]^(+X−)-based metal-organic frameworks(MOFs)catalyze the[2+1]cycloisomerization of enynes and why zwitterionic MOFs exhibit strong activity in Lewis acid catalysis.The calculations showed that zwitterionic MOFs have a“pure cationic active center”leading to a concerted nucleophilic attack pathway with lower barriers.In contrast,metals with coordinating anions have reduced electrophilicity,resulting in a stepwise radical-type pathway with much higher barriers.Further calculations showed the nature of catalysis was strongly depended on the charge on the anion ligand.A good linear relationship between the NPA charge and barrier was found,and verified by 73 anions with small derivations,which presents a universal adaptive character for various coordinated anions.
基金the National Natural Science Foundation of China(Grant Nos.21772098 and 21933004)the Fun dame ntal Research Funds for the Central Un iversities.
文摘Summary of main observation and conclusion Electrophilic trifluoromethylthiolation has emerged as an important and efficient methodology for installing the SCF3 moiety onto an array of organic molecules.Due to the low reactivities of trifluoromethylthiolating reagents,these transformations often require activation through an exogenous Lewis/Br0nsted acid.We report herein the quantification of the activation capabilities of Lewis/Br0nsted acids for trifluoromethylthiolating reagents through computing the differenee in trifluoromethylthio cation donor ability(Tt+DA)between the"activated"and"unactivated"reagent.A moderate correlation is found to exist between the activation capability and Lewis acidity.
基金We thank the National Natural Science Foundation of China(21672217,21861132003 and 22031006)the Tsinghua University Initiative Scientific Research Program for financial support.
文摘Enantioselective oxidative construction of a C(sp^(3))–S bond has been achieved using a chiral primary amine catalyst in the presence of tert-butyl hydroperoxide and a catalytic amount of tetrabutylammonium iodide.The distinctive feature of the current reaction is coupling with nucleophilic sulfur reactants under oxidative conditions.This protocol provides facile access to chiral thioethers bearing S-containing quaternary stereocenters with good chemo-and enantiocontrol.
基金supported by Beijing Natural Science Foundation(JQ22003)the National Natural Science Foundation of China(21978147 and 21935001)Beijing Municipal Natural Science Foundation(2214063)。
基金supported by the National Natural Science Foundation of China(22231011,22221002,22031006,21831008,22271192,92256301,92256303,91956116)the NSFC Distinguished Young Scholars(22225107)the Major Program of the Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences(ZYFZFX-9)。
文摘Enzymes are the core for biological transformations in nature.Their structures and functions have drawn enormous attention from biologists as well as chemists since last century.The large demand of bioactive molecules and the pursuit of efficiency and greenness of synthesis have spurred the rapid development of biomimetic chemistry in the past several decades.Biomimetic asymmetric catalysis,mimicking the structures and functions of enzymes,has been recognized as one of the most promising synthetic strategies for the synthesis of valuable chiral compounds.This review summarizes the evolution of asymmetric catalysis inspired by aldolases,vitamin B_(1)/B_(6)-dependent enzymes,NAD(P)H,flavin,hydrogenases,heme oxygenases,nonheme oxygenases,and dinuclear/multinuclear metalloenzymes in aspects of biomimetic design,catalyst development and related catalytic transformations.Those well-established synthetic approaches originating from biological reactions have demonstrated the unique prowess of biomimetic asymmetric catalysis in bridging the gap between bio-catalysis and chemical synthesis.
基金the National Natural Science Foundation of China(Grant Nos.21602116,21772098,21390400)the State Key Laboratory on Elemento-organic Chemistry,the Fundamental Research Funds for the Central UniversitiesTsinghua University Initiative Scientific Research Program(Grant Nos.20131080083,20141081295).
文摘The first comprehensive I(Ⅲ)-X(X=F,Br,CN,N3,CF3,etc.)bond dissociation energy(BDE)scales for benziodoxol(on)e-based hypervalent iodine reagents have been developed by virtue of DFT calculations.Excellent correlation is observed between the I(Ⅲ)-X BDEs and the X-H BDEs,offering a powerful avenue to quickly estimate the group-transfer ability of a novel benziodoxol(on)e-based hypervalent reagent.