Palladium nanoparticles supported by polyaniline nanofibers were used as pre-catalysts for C–C crosscoupling reactions of aryl chlorides in water.Using regular techniques,such as scanning electron microscopy(SEM),tra...Palladium nanoparticles supported by polyaniline nanofibers were used as pre-catalysts for C–C crosscoupling reactions of aryl chlorides in water.Using regular techniques,such as scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS)in conjunction with reactivity studies,we determined that a homogeneous mechanism is operating.The appearance of palladium nanoparticles and polyaniline nanofibers changes after each reaction accompanied by changes in the palladium oxidation state.Our methods could not rule out the contribution of a heterogeneous mechanism or indicate its extent.展开更多
Herein we report a nickel-catalyzed asymmetric two-component reductive aryl-acylation and arylcarbamoylation of aryl-iodide-tethered unactivated alkenes,which utilize ortho-pyridinyl esters and isocyanates as the elec...Herein we report a nickel-catalyzed asymmetric two-component reductive aryl-acylation and arylcarbamoylation of aryl-iodide-tethered unactivated alkenes,which utilize ortho-pyridinyl esters and isocyanates as the electrophilic acyl sources,respectively.Under the catalysis of a nickel–pyrox complex with zinc powder as the reductant,a variety of chiral indanes,indolines,and dihydrobenzofurans bearing a quaternary stereogenic center were prepared in moderate to high efficiency and good to excellent enantioselectivities.The utility of this method is demonstrated by various simple derivatizations of the attached carbonyl group,particularly the sequential benzylic oxidation and pinacol coupling,which provide a concise entry to the benzene-fused bicyclic bridged ring framework containing three challenging tetrasubstituted stereocenters in high stereocontrol.展开更多
The photocatalytic C–P bond formation reaction involving phosphoryl radicals provides a powerful strategy in phosphorus chemistry.However,the engagement of the phosphoryl radical-forming reaction without stoichiometr...The photocatalytic C–P bond formation reaction involving phosphoryl radicals provides a powerful strategy in phosphorus chemistry.However,the engagement of the phosphoryl radical-forming reaction without stoichiometric oxidants or radical initiators has proven difficult.展开更多
Organometallic electrochemical synthesis(OES),which combines electrochemistry with transition metal catalysis,has made remarkable headway.It employs electric current as a“traceless”redox agent,which is not only envi...Organometallic electrochemical synthesis(OES),which combines electrochemistry with transition metal catalysis,has made remarkable headway.It employs electric current as a“traceless”redox agent,which is not only environmentally friendly and renewable but also permits the regulation of metal oxidation states.Moreover,by leveraging the tunable oxidation states,electronic properties,and steric characteristics of metal catalysts,this approach enables precise control over reaction chemoselectivity,regioselectivity,and stereoselectivity.In contrast to traditional metal-catalyzed reactions that depend on stoichiometric redox reagents,this method obviates the need for such additives,potentially enhancing its practical utility.In this mini review,we summarize recent advancements in nickel catalysis integrated with electrochemistry,with a focus on carbon-carbon(C-C)and carbon-heteroatom(C-Y)bond-forming reactions.Specifically,we first spotlight recent instances of electroreductive crosscouplings for C(sp^(2))-C(sp^(2)),C(sp^(2))-C(sp^(3)),and C(sp^(3))-C(sp^(3))bonds.Subsequently,we introduce several examples of electrophileπ-addition,threecomponent reductive cross-couplings,and carboxylation.Finally,we describe C-Y bond formation,including C-O,C-N,C-S,and C-P bonds.These achievements may pave the way for breakthroughs in novel reactions,mechanistic understanding,and new synthetic modes in the field of OES.展开更多
基金supported by the National Science Foundation(CAREER Grant 0847735 to PLD and CHE-1048804 for NMR spectroscopy)。
文摘Palladium nanoparticles supported by polyaniline nanofibers were used as pre-catalysts for C–C crosscoupling reactions of aryl chlorides in water.Using regular techniques,such as scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS)in conjunction with reactivity studies,we determined that a homogeneous mechanism is operating.The appearance of palladium nanoparticles and polyaniline nanofibers changes after each reaction accompanied by changes in the palladium oxidation state.Our methods could not rule out the contribution of a heterogeneous mechanism or indicate its extent.
基金supported by start-up funds from the Young Scholar 1000 Talents Planthe National Natural Science Foundation of China(21772183 and 22071230)+2 种基金the Fundamental Research Funds for the Central Universities(WK2060190086)the Project Funded by China Postdoctoral Science Foundation(2020M682006)the University of Science and Technology of China.
文摘Herein we report a nickel-catalyzed asymmetric two-component reductive aryl-acylation and arylcarbamoylation of aryl-iodide-tethered unactivated alkenes,which utilize ortho-pyridinyl esters and isocyanates as the electrophilic acyl sources,respectively.Under the catalysis of a nickel–pyrox complex with zinc powder as the reductant,a variety of chiral indanes,indolines,and dihydrobenzofurans bearing a quaternary stereogenic center were prepared in moderate to high efficiency and good to excellent enantioselectivities.The utility of this method is demonstrated by various simple derivatizations of the attached carbonyl group,particularly the sequential benzylic oxidation and pinacol coupling,which provide a concise entry to the benzene-fused bicyclic bridged ring framework containing three challenging tetrasubstituted stereocenters in high stereocontrol.
基金support from the National Natural Science Foundation of China(nos.22088102,21933007,and 22193013)the Ministry of Science and Technology of China(nos.2017YFA0206903,2021YFA1500102,and 2021YFA1500802)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Science(no.XDB17000000)the Key Research Program of Frontier Sciences of the Chinese Academy of Science(no.QYZDY-SSW-JSC029).
文摘The photocatalytic C–P bond formation reaction involving phosphoryl radicals provides a powerful strategy in phosphorus chemistry.However,the engagement of the phosphoryl radical-forming reaction without stoichiometric oxidants or radical initiators has proven difficult.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant nos.XDA0540000 and XDB0610000)National Natural Science Foundation of China(grant nos.22425111,22361142834,and 22101294)+1 种基金National Key R&D Program of China(grant no.2021YFA1500100)Science and Technology Commission of Shanghai Municipality of Shanghai(grant nos.21ZR1476500 and 25ZR1401384).
文摘Organometallic electrochemical synthesis(OES),which combines electrochemistry with transition metal catalysis,has made remarkable headway.It employs electric current as a“traceless”redox agent,which is not only environmentally friendly and renewable but also permits the regulation of metal oxidation states.Moreover,by leveraging the tunable oxidation states,electronic properties,and steric characteristics of metal catalysts,this approach enables precise control over reaction chemoselectivity,regioselectivity,and stereoselectivity.In contrast to traditional metal-catalyzed reactions that depend on stoichiometric redox reagents,this method obviates the need for such additives,potentially enhancing its practical utility.In this mini review,we summarize recent advancements in nickel catalysis integrated with electrochemistry,with a focus on carbon-carbon(C-C)and carbon-heteroatom(C-Y)bond-forming reactions.Specifically,we first spotlight recent instances of electroreductive crosscouplings for C(sp^(2))-C(sp^(2)),C(sp^(2))-C(sp^(3)),and C(sp^(3))-C(sp^(3))bonds.Subsequently,we introduce several examples of electrophileπ-addition,threecomponent reductive cross-couplings,and carboxylation.Finally,we describe C-Y bond formation,including C-O,C-N,C-S,and C-P bonds.These achievements may pave the way for breakthroughs in novel reactions,mechanistic understanding,and new synthetic modes in the field of OES.
