A novel method for synthesis of quinazoline through the hydrogen transfer/annulation reaction using 2-nitrobenzyl alcohol and benzylamine as starting materials is presented.The reaction is catalyzed by a ruthenium(II)...A novel method for synthesis of quinazoline through the hydrogen transfer/annulation reaction using 2-nitrobenzyl alcohol and benzylamine as starting materials is presented.The reaction is catalyzed by a ruthenium(II)complex bearing a N-heterocyclic carbene nitrogen phosphine(CNP)ligand.The pronouncedα-donating capacity of the carbene within the CNP ligand of the catalyst plays a crucial role in stabilizing the catalytically active species.Additionally,the hemilability of the nitrogen facilitates the creation of coordination vacancies,which are essential for the activation of reaction substrate molecules.The synergistic interplay between these two functionalities markedly enhances catalytic efficiency.This catalytic system shows the significant catalytic activity and selectivity,along with a broad substrate adaptability.All substrates yield the target product in good to excellent yields with the maximum yield reaching 95%.Control experiments have substantiated that benzaldehyde and phenylmethanimine may serve as intermediates in the reaction,thereby reinforcing the role of benzylamine as both a hydrogen donor and a nitrogen source in the process.展开更多
An efficient strategy for construction of tricyclic thiazino[3,4-a]isoquinolines has been achieved via 4-dimethylamino-pyridine(DMAP)promoted[5+1]annulation of simple and readily available isoquinoline 1,4-zwitterion ...An efficient strategy for construction of tricyclic thiazino[3,4-a]isoquinolines has been achieved via 4-dimethylamino-pyridine(DMAP)promoted[5+1]annulation of simple and readily available isoquinoline 1,4-zwitterion withα-bromoketone.This protocol showed good substrate compatibility as an array of structurally and electronically diverse thiazino[3,4-a]isoquinolines prepared efficiently in moderate to good yields.It is particularly emphasized that although this reaction exhibits moderate stereoselectivity,the two diastereomers can be separated by column chromatography,providing an important molecular diversity foundation for the screening and structural optimization of subsequent drug lead compounds,as well as a simple and efficient method for constructing complex nitrogen-containing and sulfur-containing heterocyclic compounds.It has potential application value in the fields of medicinal chemistry and organic synthesis.展开更多
A[3+4]annulation of α-substituted allenes and Schiff bases is reported.This methodology serves as a conduit for the construction of a series of biologically important benzazepine derivatives in good to excellent yiel...A[3+4]annulation of α-substituted allenes and Schiff bases is reported.This methodology serves as a conduit for the construction of a series of biologically important benzazepine derivatives in good to excellent yields under mild conditions by an unprecedented mode involving β’-carbon of α-substituted allenes and the proposed mechanism is supported by capturing the intermediate.Moreover,this class of benzazepine derivatives exhibited potential ability of cytotoxicity toward cancer cells.展开更多
Chromones serve as versatile heterocyclic scaffolds and are common core structural units in a variety of natural products and bioactive organic molecules.This area of research,at the forefront of organic synthesis,has...Chromones serve as versatile heterocyclic scaffolds and are common core structural units in a variety of natural products and bioactive organic molecules.This area of research,at the forefront of organic synthesis,has seen remarkable progress in recent years.Among the various synthetic methodologies for accessing chromone scaffolds,the tandem annulation of o-hydroxyaryl enaminones has emerged as a robust and practical strategy.This approach,through direct vinyl C-H bond functionalization of o-hydroxyaryl enaminones,enables the construction of structurally diverse chromones(including 3-substituted chromones,2-substituted chromones,and 2,3-disubstituted chromones)and their derivatives since mid-2019.In this review,we highlight recent advances in the synthesis of various types of chromones and their derivatives,achieved through tandem direct vinyl C-H activation and chromone annulation of o-hydroxyaryl enaminones.展开更多
A new oxidative N-heterocyclic carbene(NHC)-catalyzed high-order[7+3]annulation reaction ofγ-indolyl phenols as 1,7-dinucleophiles andα,β-alkynals with the aid of Sc(OTf)_(3)is reported,enabling the highly regiosel...A new oxidative N-heterocyclic carbene(NHC)-catalyzed high-order[7+3]annulation reaction ofγ-indolyl phenols as 1,7-dinucleophiles andα,β-alkynals with the aid of Sc(OTf)_(3)is reported,enabling the highly regioselective access to unprecedented polyarene-fused ten-membered lactams bearing a bridged aryl-aryl-indole scaffold in moderate to good yields.This protocol demonstrates a broad substrate scope,good compatibility with substituents and complete regioselectivity,providing an organocatalytic modular synthetic strategy for creating medium-sized lactams.展开更多
Designing efficient,recyclable,and low-cost catalysts is crucial for the synthesis of quinoxaline derivatives.In this context,a novel N-stable Co_(2)P nano-catalyst(CoP@N–C-1.5)was developed using a templatesacrifici...Designing efficient,recyclable,and low-cost catalysts is crucial for the synthesis of quinoxaline derivatives.In this context,a novel N-stable Co_(2)P nano-catalyst(CoP@N–C-1.5)was developed using a templatesacrificial approach.The catalyst demonstrated a broad substrate scope and good functional group tolerance,achieving yields of up to 84%.Additionally,the catalyst exhibited reusability and can be recycled up to three times.The CoP@N–C-1.5 was characterized using X-ray powder diffraction(XRD),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).The results indicated that the catalyst contained Co2P nanoparticles.The X-ray photoelectron spectroscopy(XPS)further confirms the presence of Co-P.Analysis of the characterization data and experimental results revealed that the active site of the catalyst comprises N-stable Co_(2)P nanoparticles.展开更多
Polycyclic compounds are widely found in natural products and drug molecules with important biological activities,which attracted the attention of many chemists.Phosphine-catalyzed nucleophilic addition is one of the ...Polycyclic compounds are widely found in natural products and drug molecules with important biological activities,which attracted the attention of many chemists.Phosphine-catalyzed nucleophilic addition is one of the most powerful tools for the construction of various cyclic compounds with the advantages of atom economy,mild reaction conditions and simplicity of operation.Allenolates,Morita−Baylis−Hillman(MBH)alcohols and their derivatives(MBHADs),electron-deficient olefins and alkynes are very efficient substrates in phosphine mediated annulations,which formed many phosphonium species such asβ-phosphonium enolates,β-phosphonium dienolates and vinyl phosphonium ylides as intermediates.This review describes the reactivities of these phosphonium zwitterions and summarizes the synthesis of polycycle compounds through phosphine-mediated intramolecular and intermolecular sequential annulations.Thus,a systematic summary of the research process based on the phosphine-mediated sequential annulations of allenolates,MBH alcohols and MBHADs,electron-deficient olefins and alkynes are presented in Chapters 2-6,respectively.展开更多
An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a...An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles.展开更多
An efficient Pd-catalyzed double annulation reaction of 1-(2,6-dibro mophenyl)-1 H-pyrroles with arynes is developed to synthesizeπ-extended dibenzo[d,k]ullazines in good to excellent yields.For the first time,the pa...An efficient Pd-catalyzed double annulation reaction of 1-(2,6-dibro mophenyl)-1 H-pyrroles with arynes is developed to synthesizeπ-extended dibenzo[d,k]ullazines in good to excellent yields.For the first time,the parent dibenzo[d,k]ullazine core is obtained and characterized.展开更多
Sulfoxonium ylides as carbene precursors couple smoothly with thioureas in the presence of 5 mol% of rhodium(Ⅱ) acetate dimmer via carbenoid insertion to afford the corresponding 2-aminothiazoles with high chemoselec...Sulfoxonium ylides as carbene precursors couple smoothly with thioureas in the presence of 5 mol% of rhodium(Ⅱ) acetate dimmer via carbenoid insertion to afford the corresponding 2-aminothiazoles with high chemoselectivity,providing a facile and efficient approach to access a variety of 2-aminothiazole derivatives with good functional groups tolerance.展开更多
1-Substituted 1,2,3-triazoles represents‘privileged’structural scaffolds of many clinical pharmaceuticals.However,the traditional methods for their preparation mainly rely on thermal[3+2]cycloaddition of potentially...1-Substituted 1,2,3-triazoles represents‘privileged’structural scaffolds of many clinical pharmaceuticals.However,the traditional methods for their preparation mainly rely on thermal[3+2]cycloaddition of potentially dangerous acetylene and azides.Here we report a base-mediated[4+1]annulation of azoalkenes generated in situ from readily available difluoroacetaldehyde N-tosylhydrazones(DFHZ-Ts)with amines under relatively mild conditions.This azide-and acetylene-free strategy provides facile access to diverse 1-substituted 1,2,3-triazole derivatives in high yield in a regiospecific manner.This transformation has great functional group tolerance and can suit a broad substrate scope.Furthermore,the application of this novel methodology in the gram-scale synthesis of an antibiotic drug PH-027 and in the late-stage derivatization of several bioactive small molecules and clinical drugs demonstrated its generality,practicability and applicability.展开更多
The first example of TBAI/H_(2)O cooperative electrocatalytic coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines was developed. A broad range of tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones were obtaine...The first example of TBAI/H_(2)O cooperative electrocatalytic coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines was developed. A broad range of tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones were obtained in good to excellent yields with exclusive chemoselectivities and excellent regioselectivities. The H-hydrogen bond served as a key factor for the electrocatalytic production of aminomethyl radical at lower oxidative potential.展开更多
In this paper, an efficient synthesis of cyclopentenyl ketones and cyclohexenyl ketones through tertiary phosphine catalyzed [3 ＋ 2] and [4 ＋ 2] annulations of 1,2-allenic ketones with activated alkenes has been dev...In this paper, an efficient synthesis of cyclopentenyl ketones and cyclohexenyl ketones through tertiary phosphine catalyzed [3 ＋ 2] and [4 ＋ 2] annulations of 1,2-allenic ketones with activated alkenes has been developed. Compared with published synthetic methods on cyclopentenyl ketones and cyclohexenyl ketones, the protocols developed in this paper have the advantages such as readily available starting materials, mild reaction conditions and high efficiency.展开更多
Reusable acidic nickel oxide nanoparticles have been synthesized,characterized and applied as a catalyst to convert 2-aminoaryl ketones and β-ketoesters/ketones into the corresponding quinolines in good yields with h...Reusable acidic nickel oxide nanoparticles have been synthesized,characterized and applied as a catalyst to convert 2-aminoaryl ketones and β-ketoesters/ketones into the corresponding quinolines in good yields with high selectivity.This could serve as a simple and convenient procedure for the Friedlander annulations.展开更多
A mild and efficient dearomatic [3＋2] annulation reaction of 3-nitro-7-azaindoles and Morita Baylis Hillman carbonates from isatins was developed catalyzed by DMAP, affording the corresponding polycyclic spirooxindol...A mild and efficient dearomatic [3＋2] annulation reaction of 3-nitro-7-azaindoles and Morita Baylis Hillman carbonates from isatins was developed catalyzed by DMAP, affording the corresponding polycyclic spirooxindoles containing fused azaindoline architectures and vicinal quaternary centers in excellent yields（up to 96%） with high regio- and diastereoselectivity（dr 〉 19：1）. Moderate enantioselectivity（79% ee） was obtained by employing a chiral DMAP-type Lewis base catalyst.展开更多
Me OTf-catalyzed formal[4+2]annulation of styrene oxides with alkynes to afford polysubstituted naphthalenes has been realized,which undergoes sequential electrophilic cyclization/ring expansion.A range of substrates ...Me OTf-catalyzed formal[4+2]annulation of styrene oxides with alkynes to afford polysubstituted naphthalenes has been realized,which undergoes sequential electrophilic cyclization/ring expansion.A range of substrates were tolerated in the formation of naphthalene derivatives with high regioselectivity in satisfactory yields.The reaction could also be carried out on gram scale.展开更多
Ni(0)-catalyzed regio-and diastereodivergent[4+2]annulation of biphenylenes withα,βunsaturated ketones is described.This solvent-controlled diastereodivergent reaction integrates C-C bond cleavage of biphenylene and...Ni(0)-catalyzed regio-and diastereodivergent[4+2]annulation of biphenylenes withα,βunsaturated ketones is described.This solvent-controlled diastereodivergent reaction integrates C-C bond cleavage of biphenylene and C=C double bond insertion selectivity,offering a mild approach to all possible diastereoisomers of 9,10-dihydrophenanthrene derivatives from the same starting materials.展开更多
The electrooxidative[3+2]annulation of amidines with 2-arylideneindane-1,3-diones or 4-alkylidene pyrazolones is reported using NaI as a redox catalyst and electrolyte under constant current electrolysis in an undivid...The electrooxidative[3+2]annulation of amidines with 2-arylideneindane-1,3-diones or 4-alkylidene pyrazolones is reported using NaI as a redox catalyst and electrolyte under constant current electrolysis in an undivided cell.The current strategy features excellent functional group tolerance,simple operation,and mild conditions,thus providing an environmentally benign and efficient access to spiroimidazolines in moderate to good yields.展开更多
A novel route for tandem C-C/C-N formation,annulation and aromatization of hydrazones with 1,2-dichloroethane to synthesize 1 H-pyrazoles has been developed.Furthermore,the 1,2-dichloroethane serves as alkylation reag...A novel route for tandem C-C/C-N formation,annulation and aromatization of hydrazones with 1,2-dichloroethane to synthesize 1 H-pyrazoles has been developed.Furthermore,the 1,2-dichloroethane serves as alkylation reagent in good to excellent yields.This methodology features mild reaction conditions and good functional group tolerance,providing a direct approach for the preparation of 1 Hpvrazoles.展开更多
Fluoranthenes have attracted tremendous attention due to their unique optoelectronic properties and extensive applications.Although several synthetic methodologies have been developed for the preparation of fluoranthe...Fluoranthenes have attracted tremendous attention due to their unique optoelectronic properties and extensive applications.Although several synthetic methodologies have been developed for the preparation of fluoranthene derivatives,it is still unfavorable to functionalize the fluoranthene framework at different positions due to the relatively low selectivity and reactivity.Herein,a catalyst-free intramolecular[4+2]annulation between thiophenes and alkynes is developed towards the synthesis of fluoranthenes.Altogether 20 examples have been demonstrated using this method.Various functional groups can be precisely introduced into the fluoranthene skeleton at different positions by simply tuning the substituents on the thiophenes and alkynes.The conjugation of the fluoranthene can be facilely extended through different directions.Furthermore,the feasibility of this[4+2]annulation reaction is also investigated by density functional theory calculations.Therefore,this protocol provides not only a synthetic methodology towards fluoranthenes with substituents functionalized at different positions,but also an effective pathway to construct large polycyclic aromatic hydrocarbons containing fluoranthene moieties.展开更多
文摘A novel method for synthesis of quinazoline through the hydrogen transfer/annulation reaction using 2-nitrobenzyl alcohol and benzylamine as starting materials is presented.The reaction is catalyzed by a ruthenium(II)complex bearing a N-heterocyclic carbene nitrogen phosphine(CNP)ligand.The pronouncedα-donating capacity of the carbene within the CNP ligand of the catalyst plays a crucial role in stabilizing the catalytically active species.Additionally,the hemilability of the nitrogen facilitates the creation of coordination vacancies,which are essential for the activation of reaction substrate molecules.The synergistic interplay between these two functionalities markedly enhances catalytic efficiency.This catalytic system shows the significant catalytic activity and selectivity,along with a broad substrate adaptability.All substrates yield the target product in good to excellent yields with the maximum yield reaching 95%.Control experiments have substantiated that benzaldehyde and phenylmethanimine may serve as intermediates in the reaction,thereby reinforcing the role of benzylamine as both a hydrogen donor and a nitrogen source in the process.
文摘An efficient strategy for construction of tricyclic thiazino[3,4-a]isoquinolines has been achieved via 4-dimethylamino-pyridine(DMAP)promoted[5+1]annulation of simple and readily available isoquinoline 1,4-zwitterion withα-bromoketone.This protocol showed good substrate compatibility as an array of structurally and electronically diverse thiazino[3,4-a]isoquinolines prepared efficiently in moderate to good yields.It is particularly emphasized that although this reaction exhibits moderate stereoselectivity,the two diastereomers can be separated by column chromatography,providing an important molecular diversity foundation for the screening and structural optimization of subsequent drug lead compounds,as well as a simple and efficient method for constructing complex nitrogen-containing and sulfur-containing heterocyclic compounds.It has potential application value in the fields of medicinal chemistry and organic synthesis.
基金financially supported by the National Natural Science Foundation of China(No.21572271).
文摘A[3+4]annulation of α-substituted allenes and Schiff bases is reported.This methodology serves as a conduit for the construction of a series of biologically important benzazepine derivatives in good to excellent yields under mild conditions by an unprecedented mode involving β’-carbon of α-substituted allenes and the proposed mechanism is supported by capturing the intermediate.Moreover,this class of benzazepine derivatives exhibited potential ability of cytotoxicity toward cancer cells.
基金financially supported by National Natural Science Foundation of China(No.22161022).
文摘Chromones serve as versatile heterocyclic scaffolds and are common core structural units in a variety of natural products and bioactive organic molecules.This area of research,at the forefront of organic synthesis,has seen remarkable progress in recent years.Among the various synthetic methodologies for accessing chromone scaffolds,the tandem annulation of o-hydroxyaryl enaminones has emerged as a robust and practical strategy.This approach,through direct vinyl C-H bond functionalization of o-hydroxyaryl enaminones,enables the construction of structurally diverse chromones(including 3-substituted chromones,2-substituted chromones,and 2,3-disubstituted chromones)and their derivatives since mid-2019.In this review,we highlight recent advances in the synthesis of various types of chromones and their derivatives,achieved through tandem direct vinyl C-H activation and chromone annulation of o-hydroxyaryl enaminones.
基金National Natural Science Foundation of China(Nos.21971090 and 22271123)the NSF of Jiangsu Province(No.BK20230201)+1 种基金the Natural Science Foundation of Jiangsu Education Committee(No.22KJB150024)the Natural Science Foundation of Jiangsu Normal University(No.21XSRX010)。
文摘A new oxidative N-heterocyclic carbene(NHC)-catalyzed high-order[7+3]annulation reaction ofγ-indolyl phenols as 1,7-dinucleophiles andα,β-alkynals with the aid of Sc(OTf)_(3)is reported,enabling the highly regioselective access to unprecedented polyarene-fused ten-membered lactams bearing a bridged aryl-aryl-indole scaffold in moderate to good yields.This protocol demonstrates a broad substrate scope,good compatibility with substituents and complete regioselectivity,providing an organocatalytic modular synthetic strategy for creating medium-sized lactams.
基金support from the National Natural Science Foundation of China(Nos.22061017 and21862006)the Science and Technology program of Gansu Province(Nos.22YF7GG127 and 23JRRG0002)+1 种基金National innovative training program for college students(No.202310740015)the Open Project Funding of Hubei Key Laboratory of Processing and Application of Catalytic materials(No.202306004)。
文摘Designing efficient,recyclable,and low-cost catalysts is crucial for the synthesis of quinoxaline derivatives.In this context,a novel N-stable Co_(2)P nano-catalyst(CoP@N–C-1.5)was developed using a templatesacrificial approach.The catalyst demonstrated a broad substrate scope and good functional group tolerance,achieving yields of up to 84%.Additionally,the catalyst exhibited reusability and can be recycled up to three times.The CoP@N–C-1.5 was characterized using X-ray powder diffraction(XRD),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).The results indicated that the catalyst contained Co2P nanoparticles.The X-ray photoelectron spectroscopy(XPS)further confirms the presence of Co-P.Analysis of the characterization data and experimental results revealed that the active site of the catalyst comprises N-stable Co_(2)P nanoparticles.
基金the National Natural Science Foundation of China(Nos.22171147 and 21871148)for the financial support。
文摘Polycyclic compounds are widely found in natural products and drug molecules with important biological activities,which attracted the attention of many chemists.Phosphine-catalyzed nucleophilic addition is one of the most powerful tools for the construction of various cyclic compounds with the advantages of atom economy,mild reaction conditions and simplicity of operation.Allenolates,Morita−Baylis−Hillman(MBH)alcohols and their derivatives(MBHADs),electron-deficient olefins and alkynes are very efficient substrates in phosphine mediated annulations,which formed many phosphonium species such asβ-phosphonium enolates,β-phosphonium dienolates and vinyl phosphonium ylides as intermediates.This review describes the reactivities of these phosphonium zwitterions and summarizes the synthesis of polycycle compounds through phosphine-mediated intramolecular and intermolecular sequential annulations.Thus,a systematic summary of the research process based on the phosphine-mediated sequential annulations of allenolates,MBH alcohols and MBHADs,electron-deficient olefins and alkynes are presented in Chapters 2-6,respectively.
基金supported by the Intercollegiate Key Scientific Research Projects of Henan Province(15A150018)~~
文摘An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles.
基金the financial support from the National Natural Science Foundation of China(No.21772134)the Fundamental Research Funds for the Central Universities(No.20826041D4117)。
文摘An efficient Pd-catalyzed double annulation reaction of 1-(2,6-dibro mophenyl)-1 H-pyrroles with arynes is developed to synthesizeπ-extended dibenzo[d,k]ullazines in good to excellent yields.For the first time,the parent dibenzo[d,k]ullazine core is obtained and characterized.
基金support from the National Natural Science Foundation of China (Nos.81373259 and 81573286)Sichuan Science and Technology Program (Nos.2020YJ0221 and 2018JY0537)。
文摘Sulfoxonium ylides as carbene precursors couple smoothly with thioureas in the presence of 5 mol% of rhodium(Ⅱ) acetate dimmer via carbenoid insertion to afford the corresponding 2-aminothiazoles with high chemoselectivity,providing a facile and efficient approach to access a variety of 2-aminothiazole derivatives with good functional groups tolerance.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.21871043,21961130376)Department of Science and Technology of Jilin Province(Nos.20180101185JC,20190701012GH,20200801065GH)the Fundamental Research Funds for the Central Universities(Nos.2412019ZD001,2412020ZD003)。
文摘1-Substituted 1,2,3-triazoles represents‘privileged’structural scaffolds of many clinical pharmaceuticals.However,the traditional methods for their preparation mainly rely on thermal[3+2]cycloaddition of potentially dangerous acetylene and azides.Here we report a base-mediated[4+1]annulation of azoalkenes generated in situ from readily available difluoroacetaldehyde N-tosylhydrazones(DFHZ-Ts)with amines under relatively mild conditions.This azide-and acetylene-free strategy provides facile access to diverse 1-substituted 1,2,3-triazole derivatives in high yield in a regiospecific manner.This transformation has great functional group tolerance and can suit a broad substrate scope.Furthermore,the application of this novel methodology in the gram-scale synthesis of an antibiotic drug PH-027 and in the late-stage derivatization of several bioactive small molecules and clinical drugs demonstrated its generality,practicability and applicability.
基金financial support from the University of South China。
文摘The first example of TBAI/H_(2)O cooperative electrocatalytic coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines was developed. A broad range of tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones were obtained in good to excellent yields with exclusive chemoselectivities and excellent regioselectivities. The H-hydrogen bond served as a key factor for the electrocatalytic production of aminomethyl radical at lower oxidative potential.
基金the National Natural Science Foundation of China(Nos.21172057,21272058)the Research Fund for the Doctoral Program of Higher Education(No.20114104110005)forfinancial support
文摘In this paper, an efficient synthesis of cyclopentenyl ketones and cyclohexenyl ketones through tertiary phosphine catalyzed [3 ＋ 2] and [4 ＋ 2] annulations of 1,2-allenic ketones with activated alkenes has been developed. Compared with published synthetic methods on cyclopentenyl ketones and cyclohexenyl ketones, the protocols developed in this paper have the advantages such as readily available starting materials, mild reaction conditions and high efficiency.
基金the VIT University for providing the generous support to carry out this work
文摘Reusable acidic nickel oxide nanoparticles have been synthesized,characterized and applied as a catalyst to convert 2-aminoaryl ketones and β-ketoesters/ketones into the corresponding quinolines in good yields with high selectivity.This could serve as a simple and convenient procedure for the Friedlander annulations.
基金financial support from the NSFC(21572135 and 21321061)
文摘A mild and efficient dearomatic [3＋2] annulation reaction of 3-nitro-7-azaindoles and Morita Baylis Hillman carbonates from isatins was developed catalyzed by DMAP, affording the corresponding polycyclic spirooxindoles containing fused azaindoline architectures and vicinal quaternary centers in excellent yields（up to 96%） with high regio- and diastereoselectivity（dr 〉 19：1）. Moderate enantioselectivity（79% ee） was obtained by employing a chiral DMAP-type Lewis base catalyst.
基金the National Key Research and Development Program of China(No.2016YFB0401400)the National Natural Science Foundation of China(Nos.21871163 and 22071134)。
文摘Me OTf-catalyzed formal[4+2]annulation of styrene oxides with alkynes to afford polysubstituted naphthalenes has been realized,which undergoes sequential electrophilic cyclization/ring expansion.A range of substrates were tolerated in the formation of naphthalene derivatives with high regioselectivity in satisfactory yields.The reaction could also be carried out on gram scale.
基金supported by the National Natural Science Foundation of China (Nos. 21801067, U1804283, 21801066)the Central Plains Scholars and Scientists Studio Fund (No. 2018002)+2 种基金the Project funded by the Natural Science Foundation of Henan (Nos. 202300410225, 212300410181, 222102310562 and 201901023)China Postdoctoral Science Foundation (Nos. 2020T130176 and 2020M682306)financial support from Henan Key Laboratory of Organic Functional Molecules and Drug Innovation
文摘Ni(0)-catalyzed regio-and diastereodivergent[4+2]annulation of biphenylenes withα,βunsaturated ketones is described.This solvent-controlled diastereodivergent reaction integrates C-C bond cleavage of biphenylene and C=C double bond insertion selectivity,offering a mild approach to all possible diastereoisomers of 9,10-dihydrophenanthrene derivatives from the same starting materials.
基金the National Natural Science Foundation of China (No. 22078150)the Natural Science Foundation of Jiangsu Province, Frontier Project (No. BK20212003)
文摘The electrooxidative[3+2]annulation of amidines with 2-arylideneindane-1,3-diones or 4-alkylidene pyrazolones is reported using NaI as a redox catalyst and electrolyte under constant current electrolysis in an undivided cell.The current strategy features excellent functional group tolerance,simple operation,and mild conditions,thus providing an environmentally benign and efficient access to spiroimidazolines in moderate to good yields.
基金financial support for this research from Shandong Provincial Natural Science Foundation(No.ZR2017LB006)Academic promotion programme of Shandong First Medical University(No.2019LJ003)。
文摘A novel route for tandem C-C/C-N formation,annulation and aromatization of hydrazones with 1,2-dichloroethane to synthesize 1 H-pyrazoles has been developed.Furthermore,the 1,2-dichloroethane serves as alkylation reagent in good to excellent yields.This methodology features mild reaction conditions and good functional group tolerance,providing a direct approach for the preparation of 1 Hpvrazoles.
基金financially supported by National Key Research and Development Program of China(No.2018YFA0209401)National Natural Science Foundation of China(Nos.22171053,21733003)Natural Science Foundation of Shanghai(No.21ZR1409600)。
文摘Fluoranthenes have attracted tremendous attention due to their unique optoelectronic properties and extensive applications.Although several synthetic methodologies have been developed for the preparation of fluoranthene derivatives,it is still unfavorable to functionalize the fluoranthene framework at different positions due to the relatively low selectivity and reactivity.Herein,a catalyst-free intramolecular[4+2]annulation between thiophenes and alkynes is developed towards the synthesis of fluoranthenes.Altogether 20 examples have been demonstrated using this method.Various functional groups can be precisely introduced into the fluoranthene skeleton at different positions by simply tuning the substituents on the thiophenes and alkynes.The conjugation of the fluoranthene can be facilely extended through different directions.Furthermore,the feasibility of this[4+2]annulation reaction is also investigated by density functional theory calculations.Therefore,this protocol provides not only a synthetic methodology towards fluoranthenes with substituents functionalized at different positions,but also an effective pathway to construct large polycyclic aromatic hydrocarbons containing fluoranthene moieties.
