A transition-metal-free strategy for the synthesis of carboline derivatives via sequential dual C—N bond formation in a one-pot reaction is reported.Using 2,2'-dihalogenated pyridyl biaryls and primary amines as ...A transition-metal-free strategy for the synthesis of carboline derivatives via sequential dual C—N bond formation in a one-pot reaction is reported.Using 2,2'-dihalogenated pyridyl biaryls and primary amines as starting materials,this method efficiently constructs a series ofα-,β-,γ-andδ-carbolines under alkaline conditions.The reaction proceeds smoothly in the presence of lithium tert-butoxide(t-BuOLi)or cesium carbonate(Cs_(2)CO_(3))without requiring transition metal catalysts,demonstrating good functional group tolerance.This approach enables gram-scale synthesis and has been successfully applied to the preparation of the organic material 2,6-CbPy,achieving high conversion efficiency.展开更多
Dimethyl sulfoxide(DMSO)possessing strong solvency and high boiling point is a very important aprotic polar solvent in organic and polymer synthesis.Notably,it is also a useful synthon in organic chemistry.However,the...Dimethyl sulfoxide(DMSO)possessing strong solvency and high boiling point is a very important aprotic polar solvent in organic and polymer synthesis.Notably,it is also a useful synthon in organic chemistry.However,the direct incorporation of DMSO in polymer synthesis remains challenging.In this work,DMSO was successfully converted to nitrogen-containing heterocyclic polymers as a monomer via multicomponent polymerizations(MCPs)with dialdehydes and diamines in the presence of K_(2)S_(2)O_(8)/t-BuOK at 120℃in 6 h.A series of poly(phenylquinoline)s with high M_(w)values(up to 5.11×10^(4))were obtained in satisfactory yields(up to 82%),performing good solubility,good thermal and morphological stability as well as excellent film-forming ability.The thin films of poly(phenylquinoline)s exhibit high refractive index value in a wide wavelength range of 400–1700 nm.Thus,this work not only enriches the family of MCPs but also provides an efficient strategy for the conversion of DMSO into functional polymeric materials that are potentially applicable in diverse areas.展开更多
An SN2-based photochemical strategy using dithiocarbamate anion as catalyst was developed for the activation of benzyl halides,which are extremely challenging to be applied as radical precursors in visible light photo...An SN2-based photochemical strategy using dithiocarbamate anion as catalyst was developed for the activation of benzyl halides,which are extremely challenging to be applied as radical precursors in visible light photocatalysis.With this transition-metal-free and oxidant-free protocol,the benzylation(or cyanomethylation)of various heterocycles including quinoxalin-2(1H)-ones,coumarin,2-phenyl-2H-indazole,1-methyl-5-phenylpyrazin-2(1H)-one,1-(fluoromethyl)cinnolin-4(1H)-one,and 2,4-dibenzyl-1,2,4-triazine-3,5(2H,4H)-dione could be realized(46 examples,up to 98%yield).Importantly,some biologically relevant 3-benzylquinoxalin-2(1H)-ones were also be synthesized under mild conditions.展开更多
Due to the increasing demand for the sustainability of modern organic chemistry, the development of green and powerful methods for C-C and C-B bond formation is highly desired. Among them, the transition-metal-free co...Due to the increasing demand for the sustainability of modern organic chemistry, the development of green and powerful methods for C-C and C-B bond formation is highly desired. Among them, the transition-metal-free coupling reactions of gem–diborylalkanes emerge as one valuable tool for organic chemists in the last decade. The review covers selected representative examples. A comparison of these reactions with transition-metal-catalyzed reactions is provided. The recent example of α-boryl radical formation from gem–diborylalkanes is also briefly discussed.展开更多
An unmet challenge in radical relay difunctionalization of alkenes is the incorporation of two discrete transient radicals in a regiocontrolled manner under transition-metal-free conditions.Current protocols typically...An unmet challenge in radical relay difunctionalization of alkenes is the incorporation of two discrete transient radicals in a regiocontrolled manner under transition-metal-free conditions.Current protocols typically rely on persistent radicals or organometallic surrogates to trap radical adducts,thereby suppressing the undesired reactions but limiting the diversity.The direct use of two transient radicals remains synthetically elusive.We present a visible-light photoredox catalyzed alkene dialkylation strategy via a kinetically guided conjugative radical–radical coupling.This transition-metal-free approach enables two direct C(sp^(3))–C(sp^(3))bond formations across the C=C double bond using alkyl and allyl or benzyl radicals.Mechanistic investigations reveal the radical nature of the process.The success of this approach hinges on kinetically controlled radical addition to alkene substrates and the steric protection of the resulting radical adducts.This mild and functional-group-tolerant reaction exhibits broad substrate scope and tolerates structurally complex substrates,highlighting its potential for late-stage functionalization.展开更多
A novel visible-light-driven protocol has been established for the direct difunctionalization of unactivated alkenes using arylhydrazines and H-phosphine oxides as dual-function reagents.Through visible-light photocat...A novel visible-light-driven protocol has been established for the direct difunctionalization of unactivated alkenes using arylhydrazines and H-phosphine oxides as dual-function reagents.Through visible-light photocatalysis,phosphonyl radicals are generated as key intermediates,which undergo a cascade process involving radical addition,single-electron oxidation,and dehydration coupling to achieve the in-situ construction of C-P and C=N-N bonds.The method demonstrates broad substrate compatibility with excellent functional group tolerance,deliveringβ-phosphinoyl hydrazones in moderate to good yields.Notably,several synthesized compounds exhibit potent anti-proliferative activity against HepG2 cells.Mechanistic investigations through radical trapping experiments and kinetic studies confirm a radical chain pathway,with photocatalysis crucially mediating the initial radical generation and subsequent electron transfer processes.展开更多
A KOtBu-mediated C2-benzylation of quinoline N-oxides with benzylboronates under mild reaction conditions has been developed.The reaction shows broad scope for both of the quinoline N-oxides and benzylboronates,especi...A KOtBu-mediated C2-benzylation of quinoline N-oxides with benzylboronates under mild reaction conditions has been developed.The reaction shows broad scope for both of the quinoline N-oxides and benzylboronates,especially,secondary and tertiary benzylboronates are also compatible with this reaction.DFT calculations indicate that the reaction is promoted by the nucleophilic addition of KOtBu to boronate rather than the deprotonation of benzylic C−H bond with KOtBu.展开更多
Isofunctional reactions involving the cleavage of carbon-carbon double bonds(C=C)hold an important position in organic synthesis,as they allow for the restructuring of alkene carbon chains and enable the exchange of f...Isofunctional reactions involving the cleavage of carbon-carbon double bonds(C=C)hold an important position in organic synthesis,as they allow for the restructuring of alkene carbon chains and enable the exchange of functional groups without introducing exogenous groups.Currently,these reactions are primarily divided into C=C/C=C metathesis and C=C/C=O metathesis,with most relying on the use of transition metal catalysts.We report herein a C=C/CH_(2) metathesis reaction that obviates the need for transition metals and directing groups,and is characterized by economic and straightforward operation.This reaction not only facilitates the replacement of nitriles with ketones,but also enables the replacement of ketones with nitriles,demonstrating great universality.展开更多
The unique properties of fluorine-containing organic compounds make fluorine substitution attractive for the development of pharmaceuticals and various specialty materials,which have inspired the evolution of diverse ...The unique properties of fluorine-containing organic compounds make fluorine substitution attractive for the development of pharmaceuticals and various specialty materials,which have inspired the evolution of diverse C–F bond activation techniques.Although many advances have been made in functionalizations of activated C–F bonds utilizing transition metal complexes,there are fewer approaches available for nonactivated C–F bonds due to the difficulty in oxidative addition of transition metals to the inert C–F bonds.In this regard,using Lewis acid to abstract the fluoride and light/radical initiator to generate the radical intermediate have emerged as powerful tools for activating those inert C–F bonds.Meanwhile,these transition-metal-free processes are greener,economical,and for the pharmaceutical industry,without heavy metal residues.This review provides an overview of recent C–F bond activations and functionalizations under transition-metal-free conditions.The key mechanisms involved are demonstrated and discussed in detail.Finally,a brief discussion on the existing limitations of this field and our perspective are presented.展开更多
A novel,green,and transition-metal-free protocol for the facile modification of quinoline and isoquinoline derivatives is introduced,starting from readily available and environmentally benign quinoline and isoquinolin...A novel,green,and transition-metal-free protocol for the facile modification of quinoline and isoquinoline derivatives is introduced,starting from readily available and environmentally benign quinoline and isoquinoline N-oxides with propargylic alcohols in the presence of Na_(2)S_(2)O_(8) or K_(2)S_(2)O_(8) at 100℃.The one-pot transformation features the advantages of good functional group compatibility,short reaction time,operational simplicity,and highly efficient reaction system.This protocol,which produces water as the only byproduct,provides efficient and atom-economical access to a class of fascinating quinoline and isoquinoline products in satisfactory yields.The method is effective on the gram scale,thus highlighting the inherent practicality of this methodology.展开更多
A general transition-metal-free visible-light-promoted 3-acetalation reaction of quinoxaline-2(1H)-ones was developed under mild conditions.By employing 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene(4CzIPN)as an ...A general transition-metal-free visible-light-promoted 3-acetalation reaction of quinoxaline-2(1H)-ones was developed under mild conditions.By employing 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene(4CzIPN)as an inexpensive photocatalyst,and glyoxylic acid acetal as a radical source,various acetalated quinoxaline-2(1H)-ones were constructed in moderate to good yields.Moreover,the versatility of this protocol is highlighted by the successful application in the late-stage modification of drug molecules and the various functionality transformations.The excellent antitumor activity of the acetalated product demonstrated that this streamlined and sustainable approach could have emerged as a powerful strategy for structural modification in medicinal chemistry.展开更多
The amide C-N cleavage has drawn a broad interest in synthetic chemistry,biological process and pharmaceutical industry.Transition-metal,luxury ligand or excess base were always vital to the transformation.Here,we dev...The amide C-N cleavage has drawn a broad interest in synthetic chemistry,biological process and pharmaceutical industry.Transition-metal,luxury ligand or excess base were always vital to the transformation.Here,we developed a transition-metalfree hydrogen-bond-assisted esterification of amides with only catalytic amount of base.The proposed crucial role of hydrogen bonding for assisting esterification was control experiments,density functional theory(DFT)calculations and kinetic studies.Besides broad substrate scopes and excellent functional groups tolerance,this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C–N bonds for organic synthesis and pharmaceutical industry.展开更多
A multicomponent reductive cross-coupling of unactivated alkyl halides and alkyl tosylates connected via sodium metabisulfite was established for the general construction of alkyl-alkyl sulfones.Neither a metal cataly...A multicomponent reductive cross-coupling of unactivated alkyl halides and alkyl tosylates connected via sodium metabisulfite was established for the general construction of alkyl-alkyl sulfones.Neither a metal catalyst nor a metal reductant is required in this“green”reductive cross-coupling.Inorganic sodium metabisulfite served as both the sulfur dioxide source and the robust connector.展开更多
A convenient synthetic route to 2-heteroaryl-3-hydroxybenzo[b]thiophene derivatives via K_(2)CO_(3)-promoted multicomponent cycliza-tion between o-halogenated benzaldehyde,2-methylquinolines and sulfur powder has been...A convenient synthetic route to 2-heteroaryl-3-hydroxybenzo[b]thiophene derivatives via K_(2)CO_(3)-promoted multicomponent cycliza-tion between o-halogenated benzaldehyde,2-methylquinolines and sulfur powder has been demonstrated.This reaction is performed smoothly under simple conditions to give the corresponding products in moderate to good yields.The resultant 3-hydroxybenzo[b]thiophenes have been proved to be versatile building blocks in a range of transition-metal-catalyzed cross-coupling reactions.展开更多
A formal[4+3]-cycloaddition reaction of ortho-hydroxyphenyl-substituted para-quinone methides(p-QMs)with in-situ generated azaoxyallyl cations is reported.The reaction occurs under very mild reaction conditions(transi...A formal[4+3]-cycloaddition reaction of ortho-hydroxyphenyl-substituted para-quinone methides(p-QMs)with in-situ generated azaoxyallyl cations is reported.The reaction occurs under very mild reaction conditions(transition-metal free,room temperature,cheap inorganic base)and provides a very efficient route to a series of biologically important 1,4-benzoxazepine derivatives in good to excellent yields.展开更多
An efficient and practical synthetic approach was developed for the tandem synthesis of trisubstituted 2-pyrone derivatives from sulfoxonium ylides and cyclopropenones.This[3+3]annulation reaction was carried out unde...An efficient and practical synthetic approach was developed for the tandem synthesis of trisubstituted 2-pyrone derivatives from sulfoxonium ylides and cyclopropenones.This[3+3]annulation reaction was carried out under transition-metal-free conditions.A broad range of functional groups were tolerant under mild conditions,and a variety of 2-pyrones were obtained in moderate to good yields.展开更多
A facile synthesis of 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d_(5) via[4+1]cyclization of ClCF_(2)COONa with non-amine compounds containing amino groups is developed.Of note,this is the first time that halofluorinate...A facile synthesis of 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d_(5) via[4+1]cyclization of ClCF_(2)COONa with non-amine compounds containing amino groups is developed.Of note,this is the first time that halofluorinated compounds are used as C1 synthon to construct deuterated nitrogen-heterocyclic compounds.The current protocol features simple operation,readily accessible raw materials,wide substrate scope and valuable products.展开更多
2,2,6,6-Tetramethyl-l-piperidinyl-N-oxyl(TEMPO)and its derivatives as stable radicals can participate in many reactions.During the process,TEMPO and its derivatives could act not only as the substrates to capture or i...2,2,6,6-Tetramethyl-l-piperidinyl-N-oxyl(TEMPO)and its derivatives as stable radicals can participate in many reactions.During the process,TEMPO and its derivatives could act not only as the substrates to capture or initiate new radical intermediates to provide new compounds but also as organic catalysts or oxidants for transformations of alkenes,alcohols,aldehydes and so on to synthesize various high valueadded compounds.In this review,we would introduce recent advances of the transformations of different substrates mediated by TEMPO and its derivatives under transition-metal-free conditions.展开更多
A facile access to mono-C-alkynyl-o-carboranes from o-carboranes and arylsulfonylacetylenes was developed.This facile process tolerates a wide variety of functional groups,occurs at mild conditions in onepot procedure...A facile access to mono-C-alkynyl-o-carboranes from o-carboranes and arylsulfonylacetylenes was developed.This facile process tolerates a wide variety of functional groups,occurs at mild conditions in onepot procedure with short reaction time.The obtained mono-C-alkynyl-o-carboranes can be easily derivatized to synthesize 1,2-difunctionalized o-carboranes.This work provides a useful tool for the functionalization of o-carboranes.展开更多
The construction of N-methyl amine moieties is an important reaction that has found numerous applications.Development of new methylation agents that are more environmentally benign than classical agents,such as iodome...The construction of N-methyl amine moieties is an important reaction that has found numerous applications.Development of new methylation agents that are more environmentally benign than classical agents,such as iodomethane and methyl sulfate,is still highly desirable.Herein,we report a convenient protocol for direct reductive N-methylation of amines using formic acid as the methylation agent via simple inorganic base catalysis.The present protocol operates under transition-metal-free and air-tolerant conditions.Both the catalyst,K2 HPO4,and the reductant,polymethylhydrosiloxane(PMHS),are cheap and easily separable from the crude reaction product mixture.Mechanistic investigations suggest that the reaction occur through the formation of an acetal inte rmediate followed by the C-N bond formation.展开更多
基金Project supported by the National Natural Science Foundation of China(No.22371303)the Zhongshan Municipal Bureau of Science and Technology(Nos.2021B2014,CXTD2022013)the Shanghai Rising-Star Program(21QA1411000)。
文摘A transition-metal-free strategy for the synthesis of carboline derivatives via sequential dual C—N bond formation in a one-pot reaction is reported.Using 2,2'-dihalogenated pyridyl biaryls and primary amines as starting materials,this method efficiently constructs a series ofα-,β-,γ-andδ-carbolines under alkaline conditions.The reaction proceeds smoothly in the presence of lithium tert-butoxide(t-BuOLi)or cesium carbonate(Cs_(2)CO_(3))without requiring transition metal catalysts,demonstrating good functional group tolerance.This approach enables gram-scale synthesis and has been successfully applied to the preparation of the organic material 2,6-CbPy,achieving high conversion efficiency.
基金supported by the Scientific Research Start-up Fund Project of Anhui Polytechnic University for Introducing Talents(No.2022YQQ081)Natural Science Research Project of the Anhui Educational Committee(No.2024AH050133)the National Natural Science Foundation of China(No.22101088)。
文摘Dimethyl sulfoxide(DMSO)possessing strong solvency and high boiling point is a very important aprotic polar solvent in organic and polymer synthesis.Notably,it is also a useful synthon in organic chemistry.However,the direct incorporation of DMSO in polymer synthesis remains challenging.In this work,DMSO was successfully converted to nitrogen-containing heterocyclic polymers as a monomer via multicomponent polymerizations(MCPs)with dialdehydes and diamines in the presence of K_(2)S_(2)O_(8)/t-BuOK at 120℃in 6 h.A series of poly(phenylquinoline)s with high M_(w)values(up to 5.11×10^(4))were obtained in satisfactory yields(up to 82%),performing good solubility,good thermal and morphological stability as well as excellent film-forming ability.The thin films of poly(phenylquinoline)s exhibit high refractive index value in a wide wavelength range of 400–1700 nm.Thus,this work not only enriches the family of MCPs but also provides an efficient strategy for the conversion of DMSO into functional polymeric materials that are potentially applicable in diverse areas.
基金support from the National Natural Science Foundation of China(Nos.21971224,22071222,22171249)111 Project(No.D20003)+3 种基金the Key Research Projects of Universities in Henan Province(No.21A150053)the Natural Science Foundation of Henan Province(No.202300410375)China Postdoctoral Science Foundation(No.2021M692906)Henan Postdoctoral Foundation(No.202003014).
文摘An SN2-based photochemical strategy using dithiocarbamate anion as catalyst was developed for the activation of benzyl halides,which are extremely challenging to be applied as radical precursors in visible light photocatalysis.With this transition-metal-free and oxidant-free protocol,the benzylation(or cyanomethylation)of various heterocycles including quinoxalin-2(1H)-ones,coumarin,2-phenyl-2H-indazole,1-methyl-5-phenylpyrazin-2(1H)-one,1-(fluoromethyl)cinnolin-4(1H)-one,and 2,4-dibenzyl-1,2,4-triazine-3,5(2H,4H)-dione could be realized(46 examples,up to 98%yield).Importantly,some biologically relevant 3-benzylquinoxalin-2(1H)-ones were also be synthesized under mild conditions.
基金financial support from the National Natural Science Foundation of China (No. 22101261)。
文摘Due to the increasing demand for the sustainability of modern organic chemistry, the development of green and powerful methods for C-C and C-B bond formation is highly desired. Among them, the transition-metal-free coupling reactions of gem–diborylalkanes emerge as one valuable tool for organic chemists in the last decade. The review covers selected representative examples. A comparison of these reactions with transition-metal-catalyzed reactions is provided. The recent example of α-boryl radical formation from gem–diborylalkanes is also briefly discussed.
基金support of the National Natural Science Foundation of China(grant no.22271151)the Natural Science Foundation of Jiangsu Province(grant no.BK20211534)the US National Science Foundation(grant no.CHE-2154593)。
文摘An unmet challenge in radical relay difunctionalization of alkenes is the incorporation of two discrete transient radicals in a regiocontrolled manner under transition-metal-free conditions.Current protocols typically rely on persistent radicals or organometallic surrogates to trap radical adducts,thereby suppressing the undesired reactions but limiting the diversity.The direct use of two transient radicals remains synthetically elusive.We present a visible-light photoredox catalyzed alkene dialkylation strategy via a kinetically guided conjugative radical–radical coupling.This transition-metal-free approach enables two direct C(sp^(3))–C(sp^(3))bond formations across the C=C double bond using alkyl and allyl or benzyl radicals.Mechanistic investigations reveal the radical nature of the process.The success of this approach hinges on kinetically controlled radical addition to alkene substrates and the steric protection of the resulting radical adducts.This mild and functional-group-tolerant reaction exhibits broad substrate scope and tolerates structurally complex substrates,highlighting its potential for late-stage functionalization.
基金supported by Natural Science Foundation of Hunan Province(2023JJ30274 and 2023JJ30275)Scientific Research Fund of Hunan Provincial Education Department(23A0497,23B0634 and 24B0612).
文摘A novel visible-light-driven protocol has been established for the direct difunctionalization of unactivated alkenes using arylhydrazines and H-phosphine oxides as dual-function reagents.Through visible-light photocatalysis,phosphonyl radicals are generated as key intermediates,which undergo a cascade process involving radical addition,single-electron oxidation,and dehydration coupling to achieve the in-situ construction of C-P and C=N-N bonds.The method demonstrates broad substrate compatibility with excellent functional group tolerance,deliveringβ-phosphinoyl hydrazones in moderate to good yields.Notably,several synthesized compounds exhibit potent anti-proliferative activity against HepG2 cells.Mechanistic investigations through radical trapping experiments and kinetic studies confirm a radical chain pathway,with photocatalysis crucially mediating the initial radical generation and subsequent electron transfer processes.
基金the National Key Research and Development Program of China(2022YFC2303100)the National Natural Science Foundation of China(22271300,21702119)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDBO610000)the Youth Innovation Team Project of Shandong Provincial College(2022KJ180)the High-level Talent Research Start-up Project Funding of Henan Academy of Sciences(242002063)for financial support.
文摘A KOtBu-mediated C2-benzylation of quinoline N-oxides with benzylboronates under mild reaction conditions has been developed.The reaction shows broad scope for both of the quinoline N-oxides and benzylboronates,especially,secondary and tertiary benzylboronates are also compatible with this reaction.DFT calculations indicate that the reaction is promoted by the nucleophilic addition of KOtBu to boronate rather than the deprotonation of benzylic C−H bond with KOtBu.
基金supported by the National Natural Science Foundation of China(22071159)Sichuan Science and Technology Program(2018JY560)。
文摘Isofunctional reactions involving the cleavage of carbon-carbon double bonds(C=C)hold an important position in organic synthesis,as they allow for the restructuring of alkene carbon chains and enable the exchange of functional groups without introducing exogenous groups.Currently,these reactions are primarily divided into C=C/C=C metathesis and C=C/C=O metathesis,with most relying on the use of transition metal catalysts.We report herein a C=C/CH_(2) metathesis reaction that obviates the need for transition metals and directing groups,and is characterized by economic and straightforward operation.This reaction not only facilitates the replacement of nitriles with ketones,but also enables the replacement of ketones with nitriles,demonstrating great universality.
文摘The unique properties of fluorine-containing organic compounds make fluorine substitution attractive for the development of pharmaceuticals and various specialty materials,which have inspired the evolution of diverse C–F bond activation techniques.Although many advances have been made in functionalizations of activated C–F bonds utilizing transition metal complexes,there are fewer approaches available for nonactivated C–F bonds due to the difficulty in oxidative addition of transition metals to the inert C–F bonds.In this regard,using Lewis acid to abstract the fluoride and light/radical initiator to generate the radical intermediate have emerged as powerful tools for activating those inert C–F bonds.Meanwhile,these transition-metal-free processes are greener,economical,and for the pharmaceutical industry,without heavy metal residues.This review provides an overview of recent C–F bond activations and functionalizations under transition-metal-free conditions.The key mechanisms involved are demonstrated and discussed in detail.Finally,a brief discussion on the existing limitations of this field and our perspective are presented.
基金supported by the National Natural Science Foundation of China(No.21776056)the Natural Foundation of Hebei Province(CN)(Nos.B2020202010,ZD2021026).
文摘A novel,green,and transition-metal-free protocol for the facile modification of quinoline and isoquinoline derivatives is introduced,starting from readily available and environmentally benign quinoline and isoquinoline N-oxides with propargylic alcohols in the presence of Na_(2)S_(2)O_(8) or K_(2)S_(2)O_(8) at 100℃.The one-pot transformation features the advantages of good functional group compatibility,short reaction time,operational simplicity,and highly efficient reaction system.This protocol,which produces water as the only byproduct,provides efficient and atom-economical access to a class of fascinating quinoline and isoquinoline products in satisfactory yields.The method is effective on the gram scale,thus highlighting the inherent practicality of this methodology.
基金financial support from the National Natural Science Foundation of China(Nos.82003585,21971224)the Technical innovation Team of Henan Normal University(No.2022TD03)+2 种基金the Postgraduate Education Reform Project of Henan Province(Nos.2019SJGLX008Y,2019SJGLX034Y)the PostgraduateEducation Reformand QualityImprovement Project of Henan Province(No.YJS2021AL079)the Scienceand Technology Research Project(No.222102310244).
文摘A general transition-metal-free visible-light-promoted 3-acetalation reaction of quinoxaline-2(1H)-ones was developed under mild conditions.By employing 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene(4CzIPN)as an inexpensive photocatalyst,and glyoxylic acid acetal as a radical source,various acetalated quinoxaline-2(1H)-ones were constructed in moderate to good yields.Moreover,the versatility of this protocol is highlighted by the successful application in the late-stage modification of drug molecules and the various functionality transformations.The excellent antitumor activity of the acetalated product demonstrated that this streamlined and sustainable approach could have emerged as a powerful strategy for structural modification in medicinal chemistry.
基金the National Key R&D Program of China(2016YFA0202902)the National Natural Science Foundation of China(21572036,21871059,21861132002)the Department of Chemistry at Fudan University。
文摘The amide C-N cleavage has drawn a broad interest in synthetic chemistry,biological process and pharmaceutical industry.Transition-metal,luxury ligand or excess base were always vital to the transformation.Here,we developed a transition-metalfree hydrogen-bond-assisted esterification of amides with only catalytic amount of base.The proposed crucial role of hydrogen bonding for assisting esterification was control experiments,density functional theory(DFT)calculations and kinetic studies.Besides broad substrate scopes and excellent functional groups tolerance,this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C–N bonds for organic synthesis and pharmaceutical industry.
基金support provided by NSFC(nos.22071057,21971065,and 21871089)STCSM(nos.20XD1421500,20JC1416800,and 18JC1415600)+1 种基金Innovative Research Team of High-Level Local Universities in Shanghai(no.SSMU-ZLCX20180501)Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning.
文摘A multicomponent reductive cross-coupling of unactivated alkyl halides and alkyl tosylates connected via sodium metabisulfite was established for the general construction of alkyl-alkyl sulfones.Neither a metal catalyst nor a metal reductant is required in this“green”reductive cross-coupling.Inorganic sodium metabisulfite served as both the sulfur dioxide source and the robust connector.
基金supported by the National Natural Science Foundation of China(Nos.21871226,21502160,21572194)the Scientific Research Fund of Hunan Provincial Education Department(19B564)+3 种基金the Hunan Provincial Natural Science Foundation of China(No.2020JJ3032)the China Postdoctoral Science Foundation(Nos.2018M632976 and 2019T120709)the Scientific Research Fund of Xiangtan University(No.XDCX2020B110)the Open Fund of Guangdong Provincial Key Laboratory of Lumines-cence from Molecular Aggregates,Guangzhou,510640,China(South China University of Technology,No.2019B030301003).
文摘A convenient synthetic route to 2-heteroaryl-3-hydroxybenzo[b]thiophene derivatives via K_(2)CO_(3)-promoted multicomponent cycliza-tion between o-halogenated benzaldehyde,2-methylquinolines and sulfur powder has been demonstrated.This reaction is performed smoothly under simple conditions to give the corresponding products in moderate to good yields.The resultant 3-hydroxybenzo[b]thiophenes have been proved to be versatile building blocks in a range of transition-metal-catalyzed cross-coupling reactions.
基金the National Natural Science Foundation of China(21971001,21702001)the Natural Science Foundation of Anhui Province(1808085MB47)+2 种基金the Open Fund for Discipline ConstructionInstitute of Physical Science and Information TechnologyAnhui University and the Start-up Grant from Anhui University。
文摘A formal[4+3]-cycloaddition reaction of ortho-hydroxyphenyl-substituted para-quinone methides(p-QMs)with in-situ generated azaoxyallyl cations is reported.The reaction occurs under very mild reaction conditions(transition-metal free,room temperature,cheap inorganic base)and provides a very efficient route to a series of biologically important 1,4-benzoxazepine derivatives in good to excellent yields.
基金This work was supported by the National Natural Science Foundation of China(Nos.81573286 and 81373259).
文摘An efficient and practical synthetic approach was developed for the tandem synthesis of trisubstituted 2-pyrone derivatives from sulfoxonium ylides and cyclopropenones.This[3+3]annulation reaction was carried out under transition-metal-free conditions.A broad range of functional groups were tolerant under mild conditions,and a variety of 2-pyrones were obtained in moderate to good yields.
基金Financial support from the National Natural Science Foundation of China(Nos.21772046,2193103)the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)Subsidized Project for Cultivating Postgraduates’Innovative Ability in Scientific Research of Huaqiao University。
文摘A facile synthesis of 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d_(5) via[4+1]cyclization of ClCF_(2)COONa with non-amine compounds containing amino groups is developed.Of note,this is the first time that halofluorinated compounds are used as C1 synthon to construct deuterated nitrogen-heterocyclic compounds.The current protocol features simple operation,readily accessible raw materials,wide substrate scope and valuable products.
基金supported by the National Natural Science Foundation of China (No.21303231)Natural Science Foundation of Jiangsu Province (No.BK20161261)+1 种基金Natural Science Foundation of Shandong Province (No.ZR2019MB002)Shandong Agricultural University
文摘2,2,6,6-Tetramethyl-l-piperidinyl-N-oxyl(TEMPO)and its derivatives as stable radicals can participate in many reactions.During the process,TEMPO and its derivatives could act not only as the substrates to capture or initiate new radical intermediates to provide new compounds but also as organic catalysts or oxidants for transformations of alkenes,alcohols,aldehydes and so on to synthesize various high valueadded compounds.In this review,we would introduce recent advances of the transformations of different substrates mediated by TEMPO and its derivatives under transition-metal-free conditions.
基金financial support from the National Natural Science Foundation of China(Nos.21672193,21272218)the Key Scientific and Technological Project of Henan Province(No.202102310327)+3 种基金the Ministry of Industry and Information Technology(No.Z135060009002)the Postdoctoral Research Grant in Henan Province(No.001803004)the Programme of Introducing Talents of Discipline to Universities(111 Project,No.D20003)Zhengzhou University of China。
文摘A facile access to mono-C-alkynyl-o-carboranes from o-carboranes and arylsulfonylacetylenes was developed.This facile process tolerates a wide variety of functional groups,occurs at mild conditions in onepot procedure with short reaction time.The obtained mono-C-alkynyl-o-carboranes can be easily derivatized to synthesize 1,2-difunctionalized o-carboranes.This work provides a useful tool for the functionalization of o-carboranes.
基金financial support by the National Natural Science Foundation of China (No.U1532135)
文摘The construction of N-methyl amine moieties is an important reaction that has found numerous applications.Development of new methylation agents that are more environmentally benign than classical agents,such as iodomethane and methyl sulfate,is still highly desirable.Herein,we report a convenient protocol for direct reductive N-methylation of amines using formic acid as the methylation agent via simple inorganic base catalysis.The present protocol operates under transition-metal-free and air-tolerant conditions.Both the catalyst,K2 HPO4,and the reductant,polymethylhydrosiloxane(PMHS),are cheap and easily separable from the crude reaction product mixture.Mechanistic investigations suggest that the reaction occur through the formation of an acetal inte rmediate followed by the C-N bond formation.
