Metal-hydride-mediated hydrofunctionalization of alkenes usually features Markovnikov selectivity via the critical step of alkene insertion into the metal-hydride bond.This work demonstrates a relay-hydrogen atom tran...Metal-hydride-mediated hydrofunctionalization of alkenes usually features Markovnikov selectivity via the critical step of alkene insertion into the metal-hydride bond.This work demonstrates a relay-hydrogen atom transfer(relay-HAT)mode rather than an alkene insertion pathway for nickel-catalyzed anti-Markovnikov hydroalkylation of styrenes.This unprecedented mechanistic scenario overrides the conventional Markovnikov selectivity through radical addition to styrene derivatives followed by HAT between the benzyl radical and nickel(II)hydride species.In-depth theoretical studies elucidate the characteristics of this relay-HAT mode from the perspectives of the electronic effect and steric effect.Comparisons of the relay-HAT mode and alkene insertion mode for a series of nickel(II)-hydrideinvolved hydroalkylation reactions of styrene with N-based bidentate or tridentate ligands show the superiority and general applicability of the relay-HAT mode.This will provide practical guidance for ligand selection,as well as reaction design.展开更多
The arylation of C(sp^(3))-H bonds has been a priority research topic in organic synthesis.Minsici reactions have been the powerful methods for C(sp^(3))-C(sp^(2))bonds formation.Despite its mature development,the sco...The arylation of C(sp^(3))-H bonds has been a priority research topic in organic synthesis.Minsici reactions have been the powerful methods for C(sp^(3))-C(sp^(2))bonds formation.Despite its mature development,the scopes of arenes are usually suitable for elec-tron-deficient heterocyclic compounds,rather than electron-rich arenes.Herein,we report an electrooxidation-induced alkylation of electron-rich arenes with H_(2) evolution under exogenous oxidant-free conditions,avoiding the utilization of metal catalysts.This pro-tocol is well performed with various electron-rich aniline derivatives and nitrogen-containing heterocyclic compounds.We anticipate that this electro-oxidative C(sp^(3))-H arylation represents an important expansion for the classic arenes alkylation,thereby proving an attractive strategy for the developments of radical cross-coupling chemistry.展开更多
基金supported by the National Natural Science Foundation of China(grants nos.22101265,21903071 and 21822303)China Postdoctoral Science Foundation(grant no.2022M712866)+2 种基金Joint Fund of Key Technologies Research&Development Program of Henan Province(grant no.222301420006)Promotion Projects for Key Research&Development in Henan Province,China(grant no.222102310042)the Ministry of Science and Technology of the People’s Republic of China.
文摘Metal-hydride-mediated hydrofunctionalization of alkenes usually features Markovnikov selectivity via the critical step of alkene insertion into the metal-hydride bond.This work demonstrates a relay-hydrogen atom transfer(relay-HAT)mode rather than an alkene insertion pathway for nickel-catalyzed anti-Markovnikov hydroalkylation of styrenes.This unprecedented mechanistic scenario overrides the conventional Markovnikov selectivity through radical addition to styrene derivatives followed by HAT between the benzyl radical and nickel(II)hydride species.In-depth theoretical studies elucidate the characteristics of this relay-HAT mode from the perspectives of the electronic effect and steric effect.Comparisons of the relay-HAT mode and alkene insertion mode for a series of nickel(II)-hydrideinvolved hydroalkylation reactions of styrene with N-based bidentate or tridentate ligands show the superiority and general applicability of the relay-HAT mode.This will provide practical guidance for ligand selection,as well as reaction design.
基金the National Key R&D Program of China(No.2021YFA1500104)the National Natural Science Foundation of China(No.22031008)the Science Foundation of Wuhan(No.2020010601012192)。
文摘The arylation of C(sp^(3))-H bonds has been a priority research topic in organic synthesis.Minsici reactions have been the powerful methods for C(sp^(3))-C(sp^(2))bonds formation.Despite its mature development,the scopes of arenes are usually suitable for elec-tron-deficient heterocyclic compounds,rather than electron-rich arenes.Herein,we report an electrooxidation-induced alkylation of electron-rich arenes with H_(2) evolution under exogenous oxidant-free conditions,avoiding the utilization of metal catalysts.This pro-tocol is well performed with various electron-rich aniline derivatives and nitrogen-containing heterocyclic compounds.We anticipate that this electro-oxidative C(sp^(3))-H arylation represents an important expansion for the classic arenes alkylation,thereby proving an attractive strategy for the developments of radical cross-coupling chemistry.
