The catalytic oxidation of HMF involves a cascading reaction with multiple intermediate products,making it crucial to enhance the oriented adsorption capacity of specific functional groups for accelerating the entire ...The catalytic oxidation of HMF involves a cascading reaction with multiple intermediate products,making it crucial to enhance the oriented adsorption capacity of specific functional groups for accelerating the entire process.To achieve the efficient selective oxidation of HMF to FDCA,a series of NiCo_(2)O_(4)catalysts with different morphologies,such as flaky,echinoids,pompon and corolla,were prepared and characterized by XRD,SEM,TEM,BET,XPS,and FTIR.Among the four catalysts,flaky NiCo_(2)O_(4)exhibited the most excellent catalytic activity and stability,with a FDCA yield of 60.1%within 12 h at 80℃without alkali participation.The excellent performance of flaky NiCo_(2)O_(4)catalyst is attributed to the oxygen vacancies and acid sites generated by the exposed(400)facets.The oxygen vacancies and acid sites on the catalyst surface can precisely adsorb-CHO and-CH_(2)-OH of HMF,respectively,and this synergistic effect promotes the efficient production of FDCA.This work is of great significance for fundamentally study the effect of micro-topography or crystal-plane reaction properties on surfaces.展开更多
The radical difunctionalization of alkenes with sulfonyl bifunctional represents a powerful and straightforward approach to access functionalized alkane derivatives.However,both the mechanistic activation mode and the...The radical difunctionalization of alkenes with sulfonyl bifunctional represents a powerful and straightforward approach to access functionalized alkane derivatives.However,both the mechanistic activation mode and the substrate scopes of this type of radical difunctionalizations are still limited.We demonstrate herein a modular photoredox strategy for the difunctionalization of alkenes,employing arylsulfonyl acetate as the bifunctional reagent.This approach involves a radical addition/Smiles rearrangement cascade process,offering a robust alternative for the synthesis of valuableγ,γ-diaryl andγ-aryl esters.A complementary oxidative bifunctional reagents activation mode is identified to govern the radical cascade reactions,facilitating the simultaneous incorporation of aryl and carboxylate-bearing alkyl groups into the alkenes with excellent diastereoselectivity.Noteworthy features of this method include mild reaction conditions,organophotocatalysis,high atom-and step-economy,excellent functional group compatibility and great structural diversity.展开更多
The radical addition/functional group migration strategy has emerged as a powerful tool for the difunctionalization of unsaturated hydrocarbons,yet the heteroatom-mediated functional group migration remains largely un...The radical addition/functional group migration strategy has emerged as a powerful tool for the difunctionalization of unsaturated hydrocarbons,yet the heteroatom-mediated functional group migration remains largely unexplored.Herein,we report an unprecedented radical difunctionalization of alkynes employing oxime esters as bifunctional reagents through a novel C-centered radical addition/N-centered radical translocation sequence.This innovative transformation paradigm enables efficient alkylamination of alkynes under mild photocatalytic redox conditions.Mechanistic investigations reveal a cascade sequence initiated by single-electron transfer from oxime derivatives,proceeding through radical addition,6-exo-trig cyclization,and subsequent imino group migration.展开更多
Difunctionalization of alkynes represents a powerful and straightforward approach to the synthesis of complex molecules.However,the radical difunctionalization of alkynes mediated by bifunctional reagents remains chal...Difunctionalization of alkynes represents a powerful and straightforward approach to the synthesis of complex molecules.However,the radical difunctionalization of alkynes mediated by bifunctional reagents remains challenging and underexplored,despite significant progress having been made in alkene difunctionalization.Here,we report a novel arylsulfonylacetate skeleton in which aryl rings are attached to acetates through SO_(2),serving as a powerful bifunctional reagent for the alkylarylation of alkynes via vinyl-radical intermediate under photoredox conditions.This modular bifunctional reagent enables the simultaneous incorporation of a wide range of functional groups,including(hetero)aryl ring and alkyl carboxylate into alkynes,resulting in synthetically valuable all-carbon tetrasubstituted alkene derivatives.This transformation is distinguished by its redox-neutral nature,readily accessible starting materials,compatibility with diverse functional groups and its capacity to facilitate convergent synthesis.The utility of this approach was further demonstrated by the late-stage functionalization of complex molecules and the preparation of fluorescent molecules and anti-cancer drugs.展开更多
A practical method for the synthesis of allylic thioacyanates from allylic alcohols was disclosed employing K_(2)S_(2)O_(8) as the oxidant and NH_(4)SCN as the thiocyanate source.Without introducing a leaving group in...A practical method for the synthesis of allylic thioacyanates from allylic alcohols was disclosed employing K_(2)S_(2)O_(8) as the oxidant and NH_(4)SCN as the thiocyanate source.Without introducing a leaving group in advance,a series of disubstituted and monosubstituted allylic thiocyanate compounds were obtained in moderate to good yields.This transition metal-free method features mild reaction conditions,broad sub-strate scope and operational simplicity.The potential application of this method was demonstrated by some derivatization reactions of the product and mechanistic investigation indicated that a radical process is involved.展开更多
基金supported by the Swedish Energy Agency(P47500-1)the National Key R&D Program of China(2020YFA0710200)+2 种基金the National Natural Science Foundation of China(22378401 and U22A20416)the financial support from STINT(CH2019-8287)financial support from the European Union and Swedish Energy Agency(P2020-90066).
文摘The catalytic oxidation of HMF involves a cascading reaction with multiple intermediate products,making it crucial to enhance the oriented adsorption capacity of specific functional groups for accelerating the entire process.To achieve the efficient selective oxidation of HMF to FDCA,a series of NiCo_(2)O_(4)catalysts with different morphologies,such as flaky,echinoids,pompon and corolla,were prepared and characterized by XRD,SEM,TEM,BET,XPS,and FTIR.Among the four catalysts,flaky NiCo_(2)O_(4)exhibited the most excellent catalytic activity and stability,with a FDCA yield of 60.1%within 12 h at 80℃without alkali participation.The excellent performance of flaky NiCo_(2)O_(4)catalyst is attributed to the oxygen vacancies and acid sites generated by the exposed(400)facets.The oxygen vacancies and acid sites on the catalyst surface can precisely adsorb-CHO and-CH_(2)-OH of HMF,respectively,and this synergistic effect promotes the efficient production of FDCA.This work is of great significance for fundamentally study the effect of micro-topography or crystal-plane reaction properties on surfaces.
基金the National Natural Science Foundation of China(No.21901199)National Training Program of Innovation and Entrepreneurship for Undergraduates(No.S202310698011)Xi’an Jiaotong University(No.7121192002)for financial support.
文摘The radical difunctionalization of alkenes with sulfonyl bifunctional represents a powerful and straightforward approach to access functionalized alkane derivatives.However,both the mechanistic activation mode and the substrate scopes of this type of radical difunctionalizations are still limited.We demonstrate herein a modular photoredox strategy for the difunctionalization of alkenes,employing arylsulfonyl acetate as the bifunctional reagent.This approach involves a radical addition/Smiles rearrangement cascade process,offering a robust alternative for the synthesis of valuableγ,γ-diaryl andγ-aryl esters.A complementary oxidative bifunctional reagents activation mode is identified to govern the radical cascade reactions,facilitating the simultaneous incorporation of aryl and carboxylate-bearing alkyl groups into the alkenes with excellent diastereoselectivity.Noteworthy features of this method include mild reaction conditions,organophotocatalysis,high atom-and step-economy,excellent functional group compatibility and great structural diversity.
基金supported by the Shaanxi Provincial Natural Science Basic Research Plan(2025JC-YBMS-114)the National Key Research and Development Program of China(2024YFB3212500)+1 种基金the Xi’an Jiaotong University(7121192002)the Fundamental Research Funds for the Central Universities(xzy022024023)。
文摘The radical addition/functional group migration strategy has emerged as a powerful tool for the difunctionalization of unsaturated hydrocarbons,yet the heteroatom-mediated functional group migration remains largely unexplored.Herein,we report an unprecedented radical difunctionalization of alkynes employing oxime esters as bifunctional reagents through a novel C-centered radical addition/N-centered radical translocation sequence.This innovative transformation paradigm enables efficient alkylamination of alkynes under mild photocatalytic redox conditions.Mechanistic investigations reveal a cascade sequence initiated by single-electron transfer from oxime derivatives,proceeding through radical addition,6-exo-trig cyclization,and subsequent imino group migration.
基金supported by the National Natural Science Foundation of China(21901199)Xi’an Jiaotong University(7121192002)。
文摘Difunctionalization of alkynes represents a powerful and straightforward approach to the synthesis of complex molecules.However,the radical difunctionalization of alkynes mediated by bifunctional reagents remains challenging and underexplored,despite significant progress having been made in alkene difunctionalization.Here,we report a novel arylsulfonylacetate skeleton in which aryl rings are attached to acetates through SO_(2),serving as a powerful bifunctional reagent for the alkylarylation of alkynes via vinyl-radical intermediate under photoredox conditions.This modular bifunctional reagent enables the simultaneous incorporation of a wide range of functional groups,including(hetero)aryl ring and alkyl carboxylate into alkynes,resulting in synthetically valuable all-carbon tetrasubstituted alkene derivatives.This transformation is distinguished by its redox-neutral nature,readily accessible starting materials,compatibility with diverse functional groups and its capacity to facilitate convergent synthesis.The utility of this approach was further demonstrated by the late-stage functionalization of complex molecules and the preparation of fluorescent molecules and anti-cancer drugs.
基金L.Liu thanks the National Natural Science Foundation of China(21901199)Xi’an Jiaotong University(7121192002)for financial support.
文摘A practical method for the synthesis of allylic thioacyanates from allylic alcohols was disclosed employing K_(2)S_(2)O_(8) as the oxidant and NH_(4)SCN as the thiocyanate source.Without introducing a leaving group in advance,a series of disubstituted and monosubstituted allylic thiocyanate compounds were obtained in moderate to good yields.This transition metal-free method features mild reaction conditions,broad sub-strate scope and operational simplicity.The potential application of this method was demonstrated by some derivatization reactions of the product and mechanistic investigation indicated that a radical process is involved.
