The development of low-cost,earth-abundant and environmentally benign transition metal catalysts,which can catalyze multiple different types of asymmetric reactions,is an important objective in mod-ern asymmetric cata...The development of low-cost,earth-abundant and environmentally benign transition metal catalysts,which can catalyze multiple different types of asymmetric reactions,is an important objective in mod-ern asymmetric catalysis.Herein we demonstrate that a chiral Ni/P-Phos catalyst achieves three types of asymmetric reactions:allenylic substitution of racemic allenic ethers,1,4-hydroalkylation of prochiral 1,3-enynes and double alkylation of newly designed enynyl ether reagents.Three methods complement each other and produce various axially chiral allene derivatives bearing a pyrazolidine-3,5-dione unit,which is widely present in drugs and biologically active molecules with versatile pharmacological activities.展开更多
An efficient magnesium bistrifluoromethanesulfonimide[Mg（NTf_2）_2]catalyzed hydroalkylation of aromatic olefins with 1,3- diketones under solvent-free conditions has been developed.The reactions proceed smoothly to ...An efficient magnesium bistrifluoromethanesulfonimide[Mg（NTf_2）_2]catalyzed hydroalkylation of aromatic olefins with 1,3- diketones under solvent-free conditions has been developed.The reactions proceed smoothly to give the desired products in good yields in short reaction times.展开更多
Metal-free anti-Markovnikov hydroalkylation of unactivated alkenes with cyanoacetate has been developed,featuring the use of a dual-component initiator containing an organic photocatalyst and a radical precursor.When ...Metal-free anti-Markovnikov hydroalkylation of unactivated alkenes with cyanoacetate has been developed,featuring the use of a dual-component initiator containing an organic photocatalyst and a radical precursor.When combined,the two components can undergo visible light-induced singleelectron transfer,and serve as a versatile and effective alkyl radical generator.展开更多
Precisely tuning.the micro-nanoscale characteristics and synergistic effect of metal-acid sites to regulate the distribution of hydroconversion products are significant but challenging.The protonated carbocation inter...Precisely tuning.the micro-nanoscale characteristics and synergistic effect of metal-acid sites to regulate the distribution of hydroconversion products are significant but challenging.The protonated carbocation intermediates triggered by tandem reaction on metal-acid region hinder target product formation due to their high reactivity and instability.Supported M/Zeolite hydroconversion catalysts,which often excel in simple synthesis,ease of separation and recyclability.However,they usually consist of sterically unconstrained metal centers which are isolated from acid sites,only providing limited coupling-selectivity to target product.Herein,metal nanoparticles enveloped in acidic zeolite frameworks were developed and used for investigating the process of hydroalkylation of benzene to cyclohexylbenzene.We show that appropriate metal encapsulation comprising adequate efficient metal-acid units successfully avoids the more thermodynamically favorable hydrogenation of cyclohexene to cyclohexane,but steers to alkylation of cyclohexene with benzene to cyclohexylbenzene.This resulted in the highest cyclohexylbenzene yield of 47.7%among the reported work,and surpassed the performance of all supported M/Zeolite catalysts.Experimental and theoretical results supported that the abundant bifunctional metal-acid units enhance the activation frequency and probability of intermediate cyclohexene.This work might provide insights for the integration strategy of dual active site and guidance for the construction of efficient"metal-acid balance"in tandem reactions.展开更多
Bifunctional metal/zeolite materials are some of the most suitable catalysts for the direct hydroalkylation of benzene to cyclohexylbenzene.The overall catalytic performance of this reaction is strongly influenced by ...Bifunctional metal/zeolite materials are some of the most suitable catalysts for the direct hydroalkylation of benzene to cyclohexylbenzene.The overall catalytic performance of this reaction is strongly influenced by the hydrogenation,which is dependent on the metal sizes.Thus,systematically investigating the metal size effects in the hydroalkylation of benzene is essential.In this work,we successfully synthesized Ru and Pd nanoparticles on Sinopec Composition Materials No.1 zeolite with various metal sizes.We demonstrated the size-dependent catalytic activity of zeolite-supported Ru and Pd catalysts in the hydroalkylation of benzene,which can be attributed to the size-induced hydrogen spillover capability differences.Our work presents new insights into the hydroalkylation reaction and may open up a new avenue for the smart design of advanced metal/zeolite bi-functional catalysts.展开更多
A nickel-hydride(Ni H)-catalyzed migratory and nonmigratory hydroalkylation reaction of 2-alkenyl azaarenes with alkyl iodines has been established through strategic modulation of N-or P-donor ligands.This method enab...A nickel-hydride(Ni H)-catalyzed migratory and nonmigratory hydroalkylation reaction of 2-alkenyl azaarenes with alkyl iodines has been established through strategic modulation of N-or P-donor ligands.This method enables the synthesis of diverseβ-orγ-branched aromatic N-heterocycles.The mild regiodivergent protocols exhibit wide substrate scope,excellent functional tolerance,and great reaction yield with remarkable regioselectivity.Importantly,deuterium labeling studies reveal Ni H-catalyzed interrupted chain-walking mode as the mechanism behind remotedβ-selective hydroalkylation reaction—an interesting phenomenon mediated through aromatic imine directing groups.展开更多
An amide-substituted quinuclidine-borane has been identified as a more efficient hydridic hydrogen atom transfer(HAT)catalyst for the hydroalkylation of unactivated olefins under visible-light irradiation.^(1)H NMR ti...An amide-substituted quinuclidine-borane has been identified as a more efficient hydridic hydrogen atom transfer(HAT)catalyst for the hydroalkylation of unactivated olefins under visible-light irradiation.^(1)H NMR titration experiments reveal that the amide moiety of the quinuclidine-borane catalyst forms stronger hydrogen bonds with the carbonyl substrates,thereby improving the reaction yields.Furthermore,it was found that the reaction yields correlate well with the association constant between the quinuclidine-borane catalyst and the carbonyl substrate.A scale-up reaction using a continuous-flow photoreactor has also been demonstrated.展开更多
The use of simple and easily available feedstock to quickly and efficiently obtain compounds with complex molecular structures through the transition-metal-catalyzed construction of C(sp3)–C bonds has important signi...The use of simple and easily available feedstock to quickly and efficiently obtain compounds with complex molecular structures through the transition-metal-catalyzed construction of C(sp3)–C bonds has important significance.As traditional C(sp3)–C coupling reagents,alkylmetallic reagents often have limitations such as air and moisture sensitivity and difficulties in storage.Nickel-catalyzed reductive olefin hydrocarbonation reactions use alkenes to replace organometallic reagents,reduce the synthesis steps,improve the functional group compatibility,and expand the substrate scope.This minireview discusses important progress in the hydroalkylation and hydroarylation of electronically unbiased alkenes in recent years and describes the key mechanism and applications.展开更多
Comprehensive Summary Regioselective electrochemical hydroalkylations of[60]fullerene-fused furochromenone with alky halides under different acidic conditions unexpectedly afford three types of tetra-functionalized[60...Comprehensive Summary Regioselective electrochemical hydroalkylations of[60]fullerene-fused furochromenone with alky halides under different acidic conditions unexpectedly afford three types of tetra-functionalized[60]fullerene derivatives in high yields.When acetic acid is used as the proton source,two 1,2,3,4-adducts with retained or rearranged five-membered heterocycle are obtained as major and minor products,respectively.While trifluoroacetic acid is employed as the proton source,1,2,3,16-adducts and 1,2,3,4-adducts,both with the five-membered heterocycle rearranged from[6,6]-junction to[5,6]-junction,are generated.Intriguingly,the obtained 1,2,3,16-adducts can be transformed into 1,2,3,4-adducts accompanied by rearrangement of the fused five-membered heterocycle from[5,6]-junction to[6,6]-junction.These products have been characterized by spectroscopic data and single-crystal X-ray analysis.Moreover,the two 1,2,3,4-adducts with the heterocycle fused to[5,6]-junction or[6,6]-junction show diagnostic UV-vis spectra,which may be useful for the identification of these two types of 1,2,3,4-adducts in the future.A plausible reaction mechanism has been proposed to elucidate the formation of hydroalkylation products in the presence of different acids.展开更多
Chiral dialkyl carbinols and their derivatives are significant synthetic building blocks in organic chemistry and related fields.The development of convenient and efficient methods to access these compounds has long b...Chiral dialkyl carbinols and their derivatives are significant synthetic building blocks in organic chemistry and related fields.The development of convenient and efficient methods to access these compounds has long been an important endeavor.Herein,we report a NiH-catalyzed reductive hydroalkylation and hydroarylation of enol esters and ethers.α-Oxoalkyl organonickel species were generated in situ in a catalytic mode and then participated in cross-coupling with alkyl or aryl halides.This approach enabled C(sp^(3))–C(sp^(3))and C(sp^(3))–C(sp^(2))bond formation under mild reductive conditions with simple operations,thereby boosting a broad substrate scope and good functional compatibility.Esters of enantioenriched dialkyl carbinols were accessed in a catalytic asymmetric version.Mechanistic studies demonstrated that this reaction proceeded through a syn-addition of Ni–H intermediate to an enol ester with high regio-and enantioselectivity.展开更多
基金supported by the National Natural Science Foundation of China (No.22171240)
文摘The development of low-cost,earth-abundant and environmentally benign transition metal catalysts,which can catalyze multiple different types of asymmetric reactions,is an important objective in mod-ern asymmetric catalysis.Herein we demonstrate that a chiral Ni/P-Phos catalyst achieves three types of asymmetric reactions:allenylic substitution of racemic allenic ethers,1,4-hydroalkylation of prochiral 1,3-enynes and double alkylation of newly designed enynyl ether reagents.Three methods complement each other and produce various axially chiral allene derivatives bearing a pyrazolidine-3,5-dione unit,which is widely present in drugs and biologically active molecules with versatile pharmacological activities.
基金financially supported by the Special Scientific Research Project of Shaanxi Education Commission (Nos.09JK332,2010JS069)the Science Research Foundation of Baoji University of Arts and Sciences(No. ZK1053)
文摘An efficient magnesium bistrifluoromethanesulfonimide[Mg（NTf_2）_2]catalyzed hydroalkylation of aromatic olefins with 1,3- diketones under solvent-free conditions has been developed.The reactions proceed smoothly to give the desired products in good yields in short reaction times.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB17000000)the National Natural Science Foundation of China (Nos.21672227, 21922113)+3 种基金the National Key Research and Development Program of China (No.2017YFA0206903)Beijing Natural Science Foundation (No.L182020)Fundamental Research Funds for the Central Universities (No.FRF-TP-19-013B1)K.C.Wong Education Foundation,and the TIPC Director’s Fund。
文摘Metal-free anti-Markovnikov hydroalkylation of unactivated alkenes with cyanoacetate has been developed,featuring the use of a dual-component initiator containing an organic photocatalyst and a radical precursor.When combined,the two components can undergo visible light-induced singleelectron transfer,and serve as a versatile and effective alkyl radical generator.
基金This work was financially supported by the National Natural Science Foundation of China(No.22278380)China Postdoctoral Science Foundation(Nos.2021M692911,2022T150589,2023TQ0319,and 2023M743174)+1 种基金Excellent Youth of Henan Province(No.242300421122)Zhongyuan postdoctoral innovative talent support program(No.ZYYCYU202012174).
文摘Precisely tuning.the micro-nanoscale characteristics and synergistic effect of metal-acid sites to regulate the distribution of hydroconversion products are significant but challenging.The protonated carbocation intermediates triggered by tandem reaction on metal-acid region hinder target product formation due to their high reactivity and instability.Supported M/Zeolite hydroconversion catalysts,which often excel in simple synthesis,ease of separation and recyclability.However,they usually consist of sterically unconstrained metal centers which are isolated from acid sites,only providing limited coupling-selectivity to target product.Herein,metal nanoparticles enveloped in acidic zeolite frameworks were developed and used for investigating the process of hydroalkylation of benzene to cyclohexylbenzene.We show that appropriate metal encapsulation comprising adequate efficient metal-acid units successfully avoids the more thermodynamically favorable hydrogenation of cyclohexene to cyclohexane,but steers to alkylation of cyclohexene with benzene to cyclohexylbenzene.This resulted in the highest cyclohexylbenzene yield of 47.7%among the reported work,and surpassed the performance of all supported M/Zeolite catalysts.Experimental and theoretical results supported that the abundant bifunctional metal-acid units enhance the activation frequency and probability of intermediate cyclohexene.This work might provide insights for the integration strategy of dual active site and guidance for the construction of efficient"metal-acid balance"in tandem reactions.
基金supported by China Petrochemical Corporation and the National Natural Science Foundation of China(Grant Nos.U19B6002,21972168,and 22302234).
文摘Bifunctional metal/zeolite materials are some of the most suitable catalysts for the direct hydroalkylation of benzene to cyclohexylbenzene.The overall catalytic performance of this reaction is strongly influenced by the hydrogenation,which is dependent on the metal sizes.Thus,systematically investigating the metal size effects in the hydroalkylation of benzene is essential.In this work,we successfully synthesized Ru and Pd nanoparticles on Sinopec Composition Materials No.1 zeolite with various metal sizes.We demonstrated the size-dependent catalytic activity of zeolite-supported Ru and Pd catalysts in the hydroalkylation of benzene,which can be attributed to the size-induced hydrogen spillover capability differences.Our work presents new insights into the hydroalkylation reaction and may open up a new avenue for the smart design of advanced metal/zeolite bi-functional catalysts.
基金supported by the Dalian Institute of Chemical Physics,the Chinese Academy of Sciencesthe National Natural Science Foundation of China(21472186,21272231)。
文摘A nickel-hydride(Ni H)-catalyzed migratory and nonmigratory hydroalkylation reaction of 2-alkenyl azaarenes with alkyl iodines has been established through strategic modulation of N-or P-donor ligands.This method enables the synthesis of diverseβ-orγ-branched aromatic N-heterocycles.The mild regiodivergent protocols exhibit wide substrate scope,excellent functional tolerance,and great reaction yield with remarkable regioselectivity.Importantly,deuterium labeling studies reveal Ni H-catalyzed interrupted chain-walking mode as the mechanism behind remotedβ-selective hydroalkylation reaction—an interesting phenomenon mediated through aromatic imine directing groups.
基金the National Natural Science Foundation of China(grant nos.22371180 and 22001163 to Y.J.and 22361032 to H.Z.)Shanghai Jiao Tong University(SJTU)is acknowledged.Dr.Pandaram Sakthivel(SJTU)is acknowledged for reproducing the results of compounds 6,10,and 21.
文摘An amide-substituted quinuclidine-borane has been identified as a more efficient hydridic hydrogen atom transfer(HAT)catalyst for the hydroalkylation of unactivated olefins under visible-light irradiation.^(1)H NMR titration experiments reveal that the amide moiety of the quinuclidine-borane catalyst forms stronger hydrogen bonds with the carbonyl substrates,thereby improving the reaction yields.Furthermore,it was found that the reaction yields correlate well with the association constant between the quinuclidine-borane catalyst and the carbonyl substrate.A scale-up reaction using a continuous-flow photoreactor has also been demonstrated.
基金This work was supported by the National Natural Science Foundation of China(21732006,21702200,51821006,51961135104)and the Fundamental Research Funds for the Central Universities.
文摘The use of simple and easily available feedstock to quickly and efficiently obtain compounds with complex molecular structures through the transition-metal-catalyzed construction of C(sp3)–C bonds has important significance.As traditional C(sp3)–C coupling reagents,alkylmetallic reagents often have limitations such as air and moisture sensitivity and difficulties in storage.Nickel-catalyzed reductive olefin hydrocarbonation reactions use alkenes to replace organometallic reagents,reduce the synthesis steps,improve the functional group compatibility,and expand the substrate scope.This minireview discusses important progress in the hydroalkylation and hydroarylation of electronically unbiased alkenes in recent years and describes the key mechanism and applications.
基金financial support from the National Natural Science Foundation of China(22071231).
文摘Comprehensive Summary Regioselective electrochemical hydroalkylations of[60]fullerene-fused furochromenone with alky halides under different acidic conditions unexpectedly afford three types of tetra-functionalized[60]fullerene derivatives in high yields.When acetic acid is used as the proton source,two 1,2,3,4-adducts with retained or rearranged five-membered heterocycle are obtained as major and minor products,respectively.While trifluoroacetic acid is employed as the proton source,1,2,3,16-adducts and 1,2,3,4-adducts,both with the five-membered heterocycle rearranged from[6,6]-junction to[5,6]-junction,are generated.Intriguingly,the obtained 1,2,3,16-adducts can be transformed into 1,2,3,4-adducts accompanied by rearrangement of the fused five-membered heterocycle from[5,6]-junction to[6,6]-junction.These products have been characterized by spectroscopic data and single-crystal X-ray analysis.Moreover,the two 1,2,3,4-adducts with the heterocycle fused to[5,6]-junction or[6,6]-junction show diagnostic UV-vis spectra,which may be useful for the identification of these two types of 1,2,3,4-adducts in the future.A plausible reaction mechanism has been proposed to elucidate the formation of hydroalkylation products in the presence of different acids.
基金the National Natural Science Foundation of China(grant nos.21732006,51821006,21927814,and 51961135104)the Strategic Priority Research Program of CAS(grant nos.XDB20000000 and XDB37040000)+1 种基金the USTC Research Funds of the Double First-Class Initiative(grant no.YD3530002002)the Users with Excellence Program of Hefei Science Center CAS(grant nos.2019HSCUE017 and 2019HSC-UE005).
文摘Chiral dialkyl carbinols and their derivatives are significant synthetic building blocks in organic chemistry and related fields.The development of convenient and efficient methods to access these compounds has long been an important endeavor.Herein,we report a NiH-catalyzed reductive hydroalkylation and hydroarylation of enol esters and ethers.α-Oxoalkyl organonickel species were generated in situ in a catalytic mode and then participated in cross-coupling with alkyl or aryl halides.This approach enabled C(sp^(3))–C(sp^(3))and C(sp^(3))–C(sp^(2))bond formation under mild reductive conditions with simple operations,thereby boosting a broad substrate scope and good functional compatibility.Esters of enantioenriched dialkyl carbinols were accessed in a catalytic asymmetric version.Mechanistic studies demonstrated that this reaction proceeded through a syn-addition of Ni–H intermediate to an enol ester with high regio-and enantioselectivity.
