The cyclizaion reactions of Lawesson's reagent(LR) with the substrates containing two functional groups such as hydroxy groups,amino groups, has been applied to prepare the O-P-O,N-P-N type 5-membered and 6-member...The cyclizaion reactions of Lawesson's reagent(LR) with the substrates containing two functional groups such as hydroxy groups,amino groups, has been applied to prepare the O-P-O,N-P-N type 5-membered and 6-membered phosphorus heterocycles.The heterocyclizaional possibility of LR with bifunctional compounds was also discussed.展开更多
Due to the significance of corresponding products,enantioselective borylative cyclization reactions have been studied intensively in recent years.Many groups have developed efficient methods to transform unsaturated s...Due to the significance of corresponding products,enantioselective borylative cyclization reactions have been studied intensively in recent years.Many groups have developed efficient methods to transform unsaturated system into asymmetric cyclic organoboron compounds with the ring-size range from three-membered to six-membered in general.Notably,in some cases,fused rings which contain more than two contiguous chiral centers could be obtained by this kind of strategies.This review summarized and reviewed the recent advances in this field and classified these work according to the species of metal catalysts.展开更多
The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then （4R）-benzyl azetidine-2-one-4-carboxylate ...The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then （4R）-benzyl azetidine-2-one-4-carboxylate and meso-3,6-disubstituted piperazine-2,5-diones were synthesized via intramolecular cyclization and intermolecular cycfization of D-dibenzyl aspartate, respectively, and their structures were confirmed by ^1 H NMR and MS. Both cyclization reaction conditions were also investigated in detail.展开更多
Asymmetric 6-substituted-2-methoxy-4-(2,4-dichlorophenyl)-4H-1,3,2-benzodioxaphosphorin a-sulfides were prepared from intramolecular cyclization. The diastereomers were separated by column chromatography and fractiona...Asymmetric 6-substituted-2-methoxy-4-(2,4-dichlorophenyl)-4H-1,3,2-benzodioxaphosphorin a-sulfides were prepared from intramolecular cyclization. The diastereomers were separated by column chromatography and fractional crystallization. Their structures were characterized on the basis of H-1 NMR, P-31 NMR and x-ray diffraction analysis.展开更多
The crystals of the title compound C_(15)H_(17)N_2O_2PS were obtained by re crystallizing from ether-methanol solution. It belongs to the orthorhombic system, space group Pbca with a= 9. 255(1) , b= 17.189(8) , c =20....The crystals of the title compound C_(15)H_(17)N_2O_2PS were obtained by re crystallizing from ether-methanol solution. It belongs to the orthorhombic system, space group Pbca with a= 9. 255(1) , b= 17.189(8) , c =20. 446(4)A, V=3252.6 (7) A￣3, D_c=1. 31 g/cm￣3,Z= 8, μ(CuKa)=26. 87 cm-1, F(000)=1344. The structure was refined to R=0. 053, R_w=0. 055 for 1299 observed reflections (I≥3σ(I)). In the molecule P atom adopts distorted tetrahedral configuration.The bond (II)distances of P-O, P-N and P-C are 1.605(1) A, 1. 657(1) A 1. 801(1)A,(III)respectively. The X-ray crystallographic analysis demonstrates that there are intramolecular and intermolecular hydrogen bonds in the structure.展开更多
The crystal of title compound C18H16N2O was obtained by recrystal-lizing from ethanol solution. It belongs to orthorhombic system, space group Pbca witha=23. 229(2), b=11. 880(3), c=10. 733(3) A, V=2961 (0) A3, Mr=276...The crystal of title compound C18H16N2O was obtained by recrystal-lizing from ethanol solution. It belongs to orthorhombic system, space group Pbca witha=23. 229(2), b=11. 880(3), c=10. 733(3) A, V=2961 (0) A3, Mr=276. 34, Dc=1. 239 g/cm3, Z=8, A(MoKa)=0. 78 cm-1, F(000) =1168. 00. The structurewas refined to R=0. 049 and Rw=0. 046 for 1102 observed reflections (I＞2d(I) ).The bond lengths of C(3) -C(4) and C(3) -N(1) are 1. 349(5) A and 1. 340(6) A,respectively. The bond angles of N (1) -C(3) -C(2), AN (1) -C(3) -C(4), AC(2) -C(3) -C(4) and C(3) -C(4) -C(5) are 121. 1 (4), 128. 4(4), 110. 5(4)and 113. 1 (4), respectively. The dihedral angle between two phenyl rings is 29. 29.展开更多
The crystals of the title compound C19H16N2O3 were synthesized by thereaction of 4, 4-dicyano-1-phenyl-3-(3', 4'-methylenedioxyphenyl)-l-butan withlow-valent titanium reagent. It belongs to the orthorhombic sy...The crystals of the title compound C19H16N2O3 were synthesized by thereaction of 4, 4-dicyano-1-phenyl-3-(3', 4'-methylenedioxyphenyl)-l-butan withlow-valent titanium reagent. It belongs to the orthorhombic system, space group Pea21with a=11. 547(2), b=13. 168(4), c=10. 645(3) A, V=1618. 4(8) A3, Dc=1.315 g/cm3, Z=4, Mr=320.35. A=0. 71069 A, u(MoKa) =0. 90 cm-1, F(000)=672. The structure was refined to R=0. 036, Rw=0. 044 for 962 observed reflections(I＞3(I) ). X-ray analysis reveals that in the five membered ring the C(11) -C(12)bond is longer than normal double C=C bond while the C(11) -N (1) bond is shorterthan normal C(sp)2-N bond.展开更多
Visible-light photoredox catalysis is a powerful and attractive strategy for organic molecule activation and new reaction design owing to its environmental-friendly characteristics and unique catalytic mechanisms,and ...Visible-light photoredox catalysis is a powerful and attractive strategy for organic molecule activation and new reaction design owing to its environmental-friendly characteristics and unique catalytic mechanisms,and has found wide applications in organic synthesis.This catalytic strategy enables controllable generation of diverse nitrogen-centered radicals(NCRs)under mild conditions,providing access to construction of diverse nitrogencontaining compounds.In this review,we critically illustrate the recent advances in the field of visible-light photoredox-catalyzed cyclization of nitrogen-centered radicals,based on the different radical precursors and activation modes.Wherever possible,particular emphasis is also put on working models and synthetic applications.展开更多
A facile method for the carbonylative cycliza- tion of o-bromobenzoic acid with primary amine using Pd（OAC）2 as a metal precursor and 1, l′-bis（diphenylpho- sphino）ferrocene （dppf） as a ligand has been develope...A facile method for the carbonylative cycliza- tion of o-bromobenzoic acid with primary amine using Pd（OAC）2 as a metal precursor and 1, l′-bis（diphenylpho- sphino）ferrocene （dppf） as a ligand has been developed. The effect of various reaction parameters such as ligand, solvent, base, time and temperature on this cyclization was studied. The optimized protocol was used for a wide variety of substituted aryl amines with different steric and electronic properties, affording the corresponding isoindoline-l,3-diones in good to excellent yields under atmospheric pressure of carbon monoxide at 100℃ within 10h using 1,4-diazabicyclo[2.2.2]octane （DABCO） as a base. The reaction system finds attractive alternative to the conventional multistep synthetic process and thus repre- sents an effective utilization of carbonylative protocol for synthesis of valuable chemicals.展开更多
A facile synthesis of a series of new quinoline-8-carbaldehyde compounds, namely 8-formyl-2- （phenoxymethyl）quinoline-3-carboxylic acids （4a--4h） and 13-oxo-6,13-dihydro[1]benzoxepino[3,4-b]quinoline- 8-carbaldehy...A facile synthesis of a series of new quinoline-8-carbaldehyde compounds, namely 8-formyl-2- （phenoxymethyl）quinoline-3-carboxylic acids （4a--4h） and 13-oxo-6,13-dihydro[1]benzoxepino[3,4-b]quinoline- 8-carbaldehyde （5a--5g） is described, involving the one-pot synthesis reaction of ethyl 2-（chloromethyl）-8- formylquinoline-3-carboxylate （3） with substituted phenols followed by the intramolecular cyclization reaction via the treatment with polyphosphoric acid （PPA）. Quinoline-8-carbaldehydes 4a--4h and 5a--5g are novel and their structures were supported by IR, IH NMR, 13C NMR, MS and elemental analysis.展开更多
A[3+2]/[2+1]cycloaddition reaction of gem–difluorocyclopropenes is presented,offering a mild and efficient approach to accessing tri-and tetra-substituted 4-fluoropyridines in moderate to good yields with excellent r...A[3+2]/[2+1]cycloaddition reaction of gem–difluorocyclopropenes is presented,offering a mild and efficient approach to accessing tri-and tetra-substituted 4-fluoropyridines in moderate to good yields with excellent regioselectivity.Multiple synthetic applications,including process-scale reactions,modification of bioactive molecules,derivatization reactions and synthesis of the analogue of the PKM2 modulator,are subsequently described.展开更多
A highly stereoselective asymmetric cascade cyclization reaction between o-hydroxycinnamaldehydes and diphenylphosphine oxide has been achieved with 84%-99% ee and 7：1-20：1 dr under the catalysis of L-diarylprolinol...A highly stereoselective asymmetric cascade cyclization reaction between o-hydroxycinnamaldehydes and diphenylphosphine oxide has been achieved with 84%-99% ee and 7：1-20：1 dr under the catalysis of L-diarylprolinol silyl ether. This reaction provides a facile access to highly enantioenriched 4- diphenylphosphinyl chroman-2-ols. It also represents a novel organocatalytic asymmetric phospha- Michael addition of α,β-unsaturated aldehydes with pentavalent P-nucleophiles.展开更多
The cyclization reaction of 2-ethynyl-N-sulfonylanilides proceeded efficiently in water with the presence of a catalytic amount of K2CO3 under transition metal-free condition to give indoles in high yields.The recover...The cyclization reaction of 2-ethynyl-N-sulfonylanilides proceeded efficiently in water with the presence of a catalytic amount of K2CO3 under transition metal-free condition to give indoles in high yields.The recovery and reusability of the present catalytic system were investigated.展开更多
An efficient method has been developed for the cascade synthesis of azo[1,2-a]indolones from azoles and2-fluoroaldehydes based on an iron-catalyzed SNAr and a direct acylation reaction.A number of azo[1,2-a]indolones ...An efficient method has been developed for the cascade synthesis of azo[1,2-a]indolones from azoles and2-fluoroaldehydes based on an iron-catalyzed SNAr and a direct acylation reaction.A number of azo[1,2-a]indolones containing different azole rings and substituents were obtained in good yields.展开更多
An efficient and straightforward synthetic method has been developed for the preparation of 4-cyanofuran-3-carboxylate derivatives via iodine/potassium carbonate-promoted ring-opening/cyclization/rearrangement domino ...An efficient and straightforward synthetic method has been developed for the preparation of 4-cyanofuran-3-carboxylate derivatives via iodine/potassium carbonate-promoted ring-opening/cyclization/rearrangement domino reaction of 1-cyanocyclopropane-1-carboxylates,which are a wide range of structurally interesting and pharmacologically significant compounds.展开更多
It remains a significant challenge to develop a catalyst that merges the advantages of homogeneous and heterogeneous catalysis with high reactivity and great recyclability.Herein,an atomically precise Cu_(6)-NH_(2) na...It remains a significant challenge to develop a catalyst that merges the advantages of homogeneous and heterogeneous catalysis with high reactivity and great recyclability.Herein,an atomically precise Cu_(6)-NH_(2) nanocluster with distorted octahedral Cu_(6) core and NH_(2)-functionalized ligands has been developed as the first homo/heterogeneous catalyst to catalyze the cyclization reaction of propargylic amines with carbon dioxide(CO_(2))under mild conditions.As a homogeneous catalyst,Cu_(6)-NH_(2) shows excellent catalytic activity with high turnover frequency due to highly accessible active sites.The definite coordination geometry and homogeneity nature of active centers make it convenient to investigate the structure–activity relationship at the atomic level through experiments and theory calculations.In addition,the nanocluster exhibits excellent stability,great recrystallizability,and reusability in five catalytic cycles,in which its catalytic performance has no obvious decrease.Moreover,Cu_(6)-NH_(2) incorporates Lewis acid and base sites in metal and ligand,respectively,which can promote catalytic efficiency in a synergistic effect in the absence of any cocatalysts.Importantly,Cu_(6)-NH_(2) can realize direct conversion of CO_(2) in simulated flue gas into oxazolidinones with high efficiency.The metal-ligand cooperative effect and integrated advantages of homogeneous and heterogeneous catalysis would provide new perspectives to achieve advanced metal nanocluster catalysts for CO_(2) conversion.展开更多
A simple and effective method for the preparation of amphiphilic graphene(AG)is presented under an organic solvent-free synthetic condition.The synthetic route first involves a cyclization reaction between carboxylic ...A simple and effective method for the preparation of amphiphilic graphene(AG)is presented under an organic solvent-free synthetic condition.The synthetic route first involves a cyclization reaction between carboxylic groups on graphene oxide and the amino groups on 5,6-diaminopyrazine-2,3-dicarbonitrile,and subsequent reduction by hydrazine.Results of UV-vis spectroscopy,Fourier transformed infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),thermogravimetric analysis(TGA)and Raman spectroscopy have confirmed that the covalent functionalization of graphene can be achieved through the formation of imidazo[4,5-b]pyrazine on the graphene sheets.As a result,AG can be successfully dispersed in water and common organic solvents.This work successfully provides a facile and efficient way to fabricate AG and may extend the potential applications of graphene-based materials in nanoelectronic devices,polymer fillers and biological field.展开更多
A fast and efficient method is described for the one-pot synthesis of 2,4（1H,3H）-quinazolinediones by cyclization reaction of anthranilic acid derivatives with potassium cyanate and acetic acid in PEG.Good to high y...A fast and efficient method is described for the one-pot synthesis of 2,4（1H,3H）-quinazolinediones by cyclization reaction of anthranilic acid derivatives with potassium cyanate and acetic acid in PEG.Good to high yields of the products obtain in short reaction times with simple work-up.展开更多
The YCl3-catalyzed aerobic oxidative cyclization reaction for the synthesis of benzothiazoles has been developed. This method provides a practical, effective and green synthetic approach to benzothiazoles which are im...The YCl3-catalyzed aerobic oxidative cyclization reaction for the synthesis of benzothiazoles has been developed. This method provides a practical, effective and green synthetic approach to benzothiazoles which are important units in many biologically active compounds.展开更多
Fluoroalkyl-containing organic compounds have exhibited wide applications in the field of pharmaceuticals,agrochemicals and materials science due to their outstanding properties such as biological activity,metabolic s...Fluoroalkyl-containing organic compounds have exhibited wide applications in the field of pharmaceuticals,agrochemicals and materials science due to their outstanding properties such as biological activity,metabolic stability,lipophilicity,excellent chemical and thermal stability.Therefore,various synthetic strategies have been developed for the construction of fluoroalkyl-containing compounds,using highly active fluorinating reagents and fluorinated building blocks.Recently,the use of easily available and inexpensive trifluoroacetic anhydride(TFAA)and its anhydride analogues has attracted great attention to access numerous fluoroalkyl-containing compounds through cyclization and coupling reactions.In this review,we summarized the recent advances in the synthesis of fluoroalkylated compounds using fluoroalkyl anhydrides as reagents.This review aims to provide a reference for researchers on how to develop new synthetic straregies of fluorine-containing organic compounds and achieve kilograms or even tons preparation of fluorine-containing organic compounds using fluoroalkyl anhydrides.展开更多
文摘The cyclizaion reactions of Lawesson's reagent(LR) with the substrates containing two functional groups such as hydroxy groups,amino groups, has been applied to prepare the O-P-O,N-P-N type 5-membered and 6-membered phosphorus heterocycles.The heterocyclizaional possibility of LR with bifunctional compounds was also discussed.
基金Financial support from Tianjin University and the National Natural Science Foundation of China(No.21801181)is acknowledged.
文摘Due to the significance of corresponding products,enantioselective borylative cyclization reactions have been studied intensively in recent years.Many groups have developed efficient methods to transform unsaturated system into asymmetric cyclic organoboron compounds with the ring-size range from three-membered to six-membered in general.Notably,in some cases,fused rings which contain more than two contiguous chiral centers could be obtained by this kind of strategies.This review summarized and reviewed the recent advances in this field and classified these work according to the species of metal catalysts.
基金This work is supported by the National Natural Science Foundation of China （No. 20442004 10576002）.
文摘The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then （4R）-benzyl azetidine-2-one-4-carboxylate and meso-3,6-disubstituted piperazine-2,5-diones were synthesized via intramolecular cyclization and intermolecular cycfization of D-dibenzyl aspartate, respectively, and their structures were confirmed by ^1 H NMR and MS. Both cyclization reaction conditions were also investigated in detail.
文摘Asymmetric 6-substituted-2-methoxy-4-(2,4-dichlorophenyl)-4H-1,3,2-benzodioxaphosphorin a-sulfides were prepared from intramolecular cyclization. The diastereomers were separated by column chromatography and fractional crystallization. Their structures were characterized on the basis of H-1 NMR, P-31 NMR and x-ray diffraction analysis.
文摘The crystals of the title compound C_(15)H_(17)N_2O_2PS were obtained by re crystallizing from ether-methanol solution. It belongs to the orthorhombic system, space group Pbca with a= 9. 255(1) , b= 17.189(8) , c =20. 446(4)A, V=3252.6 (7) A￣3, D_c=1. 31 g/cm￣3,Z= 8, μ(CuKa)=26. 87 cm-1, F(000)=1344. The structure was refined to R=0. 053, R_w=0. 055 for 1299 observed reflections (I≥3σ(I)). In the molecule P atom adopts distorted tetrahedral configuration.The bond (II)distances of P-O, P-N and P-C are 1.605(1) A, 1. 657(1) A 1. 801(1)A,(III)respectively. The X-ray crystallographic analysis demonstrates that there are intramolecular and intermolecular hydrogen bonds in the structure.
文摘The crystal of title compound C18H16N2O was obtained by recrystal-lizing from ethanol solution. It belongs to orthorhombic system, space group Pbca witha=23. 229(2), b=11. 880(3), c=10. 733(3) A, V=2961 (0) A3, Mr=276. 34, Dc=1. 239 g/cm3, Z=8, A(MoKa)=0. 78 cm-1, F(000) =1168. 00. The structurewas refined to R=0. 049 and Rw=0. 046 for 1102 observed reflections (I＞2d(I) ).The bond lengths of C(3) -C(4) and C(3) -N(1) are 1. 349(5) A and 1. 340(6) A,respectively. The bond angles of N (1) -C(3) -C(2), AN (1) -C(3) -C(4), AC(2) -C(3) -C(4) and C(3) -C(4) -C(5) are 121. 1 (4), 128. 4(4), 110. 5(4)and 113. 1 (4), respectively. The dihedral angle between two phenyl rings is 29. 29.
文摘The crystals of the title compound C19H16N2O3 were synthesized by thereaction of 4, 4-dicyano-1-phenyl-3-(3', 4'-methylenedioxyphenyl)-l-butan withlow-valent titanium reagent. It belongs to the orthorhombic system, space group Pea21with a=11. 547(2), b=13. 168(4), c=10. 645(3) A, V=1618. 4(8) A3, Dc=1.315 g/cm3, Z=4, Mr=320.35. A=0. 71069 A, u(MoKa) =0. 90 cm-1, F(000)=672. The structure was refined to R=0. 036, Rw=0. 044 for 962 observed reflections(I＞3(I) ). X-ray analysis reveals that in the five membered ring the C(11) -C(12)bond is longer than normal double C=C bond while the C(11) -N (1) bond is shorterthan normal C(sp)2-N bond.
基金The authors’works in this area have been sponsored by the National Natural Science Foundation of China(Nos.91856119,21971081,21622201,21820102003,91956201 and 21772053)the Program of Introducing Talents of Discipline to Universities of China(111 Program,No.B17019).
文摘Visible-light photoredox catalysis is a powerful and attractive strategy for organic molecule activation and new reaction design owing to its environmental-friendly characteristics and unique catalytic mechanisms,and has found wide applications in organic synthesis.This catalytic strategy enables controllable generation of diverse nitrogen-centered radicals(NCRs)under mild conditions,providing access to construction of diverse nitrogencontaining compounds.In this review,we critically illustrate the recent advances in the field of visible-light photoredox-catalyzed cyclization of nitrogen-centered radicals,based on the different radical precursors and activation modes.Wherever possible,particular emphasis is also put on working models and synthetic applications.
文摘A facile method for the carbonylative cycliza- tion of o-bromobenzoic acid with primary amine using Pd（OAC）2 as a metal precursor and 1, l′-bis（diphenylpho- sphino）ferrocene （dppf） as a ligand has been developed. The effect of various reaction parameters such as ligand, solvent, base, time and temperature on this cyclization was studied. The optimized protocol was used for a wide variety of substituted aryl amines with different steric and electronic properties, affording the corresponding isoindoline-l,3-diones in good to excellent yields under atmospheric pressure of carbon monoxide at 100℃ within 10h using 1,4-diazabicyclo[2.2.2]octane （DABCO） as a base. The reaction system finds attractive alternative to the conventional multistep synthetic process and thus repre- sents an effective utilization of carbonylative protocol for synthesis of valuable chemicals.
文摘A facile synthesis of a series of new quinoline-8-carbaldehyde compounds, namely 8-formyl-2- （phenoxymethyl）quinoline-3-carboxylic acids （4a--4h） and 13-oxo-6,13-dihydro[1]benzoxepino[3,4-b]quinoline- 8-carbaldehyde （5a--5g） is described, involving the one-pot synthesis reaction of ethyl 2-（chloromethyl）-8- formylquinoline-3-carboxylate （3） with substituted phenols followed by the intramolecular cyclization reaction via the treatment with polyphosphoric acid （PPA）. Quinoline-8-carbaldehydes 4a--4h and 5a--5g are novel and their structures were supported by IR, IH NMR, 13C NMR, MS and elemental analysis.
基金the National Natural Science Foundation of China(Nos.21861007,21702034)Natural Science Foundation of Guangxi Province(No.2021GXNSFAA075024)+2 种基金“BAGUI Scholar”Program of Guangxi Province of ChinaHigh-Level Innovation Team and Distinguished Scholar Program in Guangxi Colleges and Universitiesthe Jiangxi Province Science and Technology Project(No.20212BAB213024)。
文摘A[3+2]/[2+1]cycloaddition reaction of gem–difluorocyclopropenes is presented,offering a mild and efficient approach to accessing tri-and tetra-substituted 4-fluoropyridines in moderate to good yields with excellent regioselectivity.Multiple synthetic applications,including process-scale reactions,modification of bioactive molecules,derivatization reactions and synthesis of the analogue of the PKM2 modulator,are subsequently described.
基金Financial support from the National Natural Science Foundation of China(Nos. 21472096, J1103306)
文摘A highly stereoselective asymmetric cascade cyclization reaction between o-hydroxycinnamaldehydes and diphenylphosphine oxide has been achieved with 84%-99% ee and 7：1-20：1 dr under the catalysis of L-diarylprolinol silyl ether. This reaction provides a facile access to highly enantioenriched 4- diphenylphosphinyl chroman-2-ols. It also represents a novel organocatalytic asymmetric phospha- Michael addition of α,β-unsaturated aldehydes with pentavalent P-nucleophiles.
基金supported by the National Natural Science Foundation of China (No. 21402137)Xinmiao Talents Program of Zhejiang Province (No. 2016R430021)
文摘The cyclization reaction of 2-ethynyl-N-sulfonylanilides proceeded efficiently in water with the presence of a catalytic amount of K2CO3 under transition metal-free condition to give indoles in high yields.The recovery and reusability of the present catalytic system were investigated.
基金financially supported by the Natural Science Foundation of China(Nos.21302135 and 21272169)Taizhou Science & Technology program(No.111ZD02)
文摘An efficient method has been developed for the cascade synthesis of azo[1,2-a]indolones from azoles and2-fluoroaldehydes based on an iron-catalyzed SNAr and a direct acylation reaction.A number of azo[1,2-a]indolones containing different azole rings and substituents were obtained in good yields.
基金Financial support of this research by the National Natural Science Foundation of China (NSFC No. 21173181) is gratefully acknowledged by authorsfunded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘An efficient and straightforward synthetic method has been developed for the preparation of 4-cyanofuran-3-carboxylate derivatives via iodine/potassium carbonate-promoted ring-opening/cyclization/rearrangement domino reaction of 1-cyanocyclopropane-1-carboxylates,which are a wide range of structurally interesting and pharmacologically significant compounds.
基金financially supported by the National Natural Science Foundation of China(grant nos.92061201,21825106,21771163,and 22371263)the National Key R&D Program of China(grant no.2021YFA1200301)+1 种基金the Natural Science Foundation of Henan Province(grant no.232300421144)the Zhongyuan Thousand Talents(Zhongyuan Scholars)Program of Henan Province(grant no.234000510007).
文摘It remains a significant challenge to develop a catalyst that merges the advantages of homogeneous and heterogeneous catalysis with high reactivity and great recyclability.Herein,an atomically precise Cu_(6)-NH_(2) nanocluster with distorted octahedral Cu_(6) core and NH_(2)-functionalized ligands has been developed as the first homo/heterogeneous catalyst to catalyze the cyclization reaction of propargylic amines with carbon dioxide(CO_(2))under mild conditions.As a homogeneous catalyst,Cu_(6)-NH_(2) shows excellent catalytic activity with high turnover frequency due to highly accessible active sites.The definite coordination geometry and homogeneity nature of active centers make it convenient to investigate the structure–activity relationship at the atomic level through experiments and theory calculations.In addition,the nanocluster exhibits excellent stability,great recrystallizability,and reusability in five catalytic cycles,in which its catalytic performance has no obvious decrease.Moreover,Cu_(6)-NH_(2) incorporates Lewis acid and base sites in metal and ligand,respectively,which can promote catalytic efficiency in a synergistic effect in the absence of any cocatalysts.Importantly,Cu_(6)-NH_(2) can realize direct conversion of CO_(2) in simulated flue gas into oxazolidinones with high efficiency.The metal-ligand cooperative effect and integrated advantages of homogeneous and heterogeneous catalysis would provide new perspectives to achieve advanced metal nanocluster catalysts for CO_(2) conversion.
基金supported by the NSFC for Excellent Young Scholars(Grant No.21322402)National Natural Science Foundation of China(Grant Nos.21274064,61204095,51173081)+2 种基金the Program for New Century Excellent Talents in University(Grant No.NCET-11-0992)Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK2011761,BK2012431,BK2009025)NJUPT(Grant No.NY211022)
文摘A simple and effective method for the preparation of amphiphilic graphene(AG)is presented under an organic solvent-free synthetic condition.The synthetic route first involves a cyclization reaction between carboxylic groups on graphene oxide and the amino groups on 5,6-diaminopyrazine-2,3-dicarbonitrile,and subsequent reduction by hydrazine.Results of UV-vis spectroscopy,Fourier transformed infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),thermogravimetric analysis(TGA)and Raman spectroscopy have confirmed that the covalent functionalization of graphene can be achieved through the formation of imidazo[4,5-b]pyrazine on the graphene sheets.As a result,AG can be successfully dispersed in water and common organic solvents.This work successfully provides a facile and efficient way to fabricate AG and may extend the potential applications of graphene-based materials in nanoelectronic devices,polymer fillers and biological field.
基金the University of Kurdistan Research Council for the partial support of this work
文摘A fast and efficient method is described for the one-pot synthesis of 2,4（1H,3H）-quinazolinediones by cyclization reaction of anthranilic acid derivatives with potassium cyanate and acetic acid in PEG.Good to high yields of the products obtain in short reaction times with simple work-up.
基金the National Natural Science Foundation of China(No.20802052)for financial support
文摘The YCl3-catalyzed aerobic oxidative cyclization reaction for the synthesis of benzothiazoles has been developed. This method provides a practical, effective and green synthetic approach to benzothiazoles which are important units in many biologically active compounds.
基金supported by the National Natural Science Foundation of China(Nos.21772022,and 22171124)Minjiang University(No.MJY21041)Fuzhou University.
文摘Fluoroalkyl-containing organic compounds have exhibited wide applications in the field of pharmaceuticals,agrochemicals and materials science due to their outstanding properties such as biological activity,metabolic stability,lipophilicity,excellent chemical and thermal stability.Therefore,various synthetic strategies have been developed for the construction of fluoroalkyl-containing compounds,using highly active fluorinating reagents and fluorinated building blocks.Recently,the use of easily available and inexpensive trifluoroacetic anhydride(TFAA)and its anhydride analogues has attracted great attention to access numerous fluoroalkyl-containing compounds through cyclization and coupling reactions.In this review,we summarized the recent advances in the synthesis of fluoroalkylated compounds using fluoroalkyl anhydrides as reagents.This review aims to provide a reference for researchers on how to develop new synthetic straregies of fluorine-containing organic compounds and achieve kilograms or even tons preparation of fluorine-containing organic compounds using fluoroalkyl anhydrides.
