Ga(ClO4)3-catalyzed reaction of 1,2-aryldiamines and α-bromoketones to afford 2-substituted quinoxalines in good yields is described.The reaction proceeded via grinding process with 10%(molar fraction) catalyst u...Ga(ClO4)3-catalyzed reaction of 1,2-aryldiamines and α-bromoketones to afford 2-substituted quinoxalines in good yields is described.The reaction proceeded via grinding process with 10%(molar fraction) catalyst under solvent-free conditions at room temperature.For unsymmetrical o-phenylenediamines bearing electron-withdrawing groups,regio-selective quinoxalines were obtained.展开更多
A facile procedure for the synthesis of 3-(2′-amino-3′-cyano-4′-arylpyrid-6′-yl) coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out...A facile procedure for the synthesis of 3-(2′-amino-3′-cyano-4′-arylpyrid-6′-yl) coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out on microwave irradiation in good yield with short time and easy work-up. The structures of all the compounds have been confirmed on the basis of their analytical, IR, ^1H NMR, and mass spectral data.展开更多
A variety of vinamidinium salts were condensated with cyanoacetamide in refluxing methanol that contained sodium methoxide to produce 5-aryl-3-cyano-2-pyridones in good yield. Simple experimental conditions were used ...A variety of vinamidinium salts were condensated with cyanoacetamide in refluxing methanol that contained sodium methoxide to produce 5-aryl-3-cyano-2-pyridones in good yield. Simple experimental conditions were used to prepare ten different 5-aryl-3- cyano-2-pyridones, four of which are new compounds.C 2009 Song Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Lithium rich layered oxide(LRLO) has been considered as one of the promising cathodes for lithium-ion batteries(LIBs). The high voltage and large capacity of LRLO depend on Li2MnO_(3)phase. To ameliorate the electroch...Lithium rich layered oxide(LRLO) has been considered as one of the promising cathodes for lithium-ion batteries(LIBs). The high voltage and large capacity of LRLO depend on Li2MnO_(3)phase. To ameliorate the electrochemical performance of Li2MnO_(3), also written as Li(Li1/3Mn2/3)O_(2), we propose a strategy to substitute Mn4+and Li+in Mn/Li transition metal layer with Ti4+, which can stabilize the structure of Li2MnO_(3)by inhibiting the excessive oxidation of O_(2)-above 4.5 V. More significantly, the unequal-valent substitution brings about the emergence of interlayer Li vacancies, which can promote the Li-ion diffusion based on the enlarged interlayer and increase the capacity by activating the Mn3+/4+redox. We designed Li0.7[Li1/3Mn2/3]0.7Ti0.3O_(2)with high interlayer Li vacancies, which presents a high capacity(290 m Ah/g at 10 m A/g) and stable cycling performance(84% over 60 cycles at 50 m A/g). We predict that this strategy will be helpful to further improve the electrochemical performance of LRLOs.展开更多
A facile one-pot synthesis of 3,4,5-substituted furan-2(5H)-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using t...A facile one-pot synthesis of 3,4,5-substituted furan-2(5H)-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using tetra-n-butylammonium bisulfate as a catalyst has been developed.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
Cyclopropanedicarboxylic acid anhydride can be converted to 4-substituted 3-oxabicyclo- [3.1.0]hexan-2-one by reaction with Grignard reagents in ether or tetrahydrofuran solution.
A rapid, one-pot and highly efficient protocol for the synthesis of pharmaceutically interesting functionalized 2-amino-3-cyano-4H-pyran and spirooxindole derivatives has been developed using commercially available Cs...A rapid, one-pot and highly efficient protocol for the synthesis of pharmaceutically interesting functionalized 2-amino-3-cyano-4H-pyran and spirooxindole derivatives has been developed using commercially available Cs F as a catalyst in the reaction of malononitrile and aryl aldehydes or isatins with 1,3-cyclohexanediones. The major advantages of this methodology are excellent yield at ambient temperature, very short reaction time(5–10 min), and use of an inexpensive catalyst.展开更多
An efficient three-component synthesis of 6-amino-4-aryl-5-cyano-3-metriyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles via a reaction between 3-methyl-1-phenyl-2-pyrazolin-5-one,aromatic aldehydes and malononitrile usi...An efficient three-component synthesis of 6-amino-4-aryl-5-cyano-3-metriyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles via a reaction between 3-methyl-1-phenyl-2-pyrazolin-5-one,aromatic aldehydes and malononitrile using tungstate sulfuric acid as a catalyst was described.Mild conditions,good to excellent yields,easily available catalyst and easy work-up are the key features of this method.展开更多
An efficient method for the synthesis of novel benzo[b]pyrimido[4′,5′:5,4]thieno[2,3e]-[1,6]naphthyridine-8-one derivatives via Pictet-Spengler cyclization is reported. The reaction of 4-(3-aminopyrimido[4,5-d]thi...An efficient method for the synthesis of novel benzo[b]pyrimido[4′,5′:5,4]thieno[2,3e]-[1,6]naphthyridine-8-one derivatives via Pictet-Spengler cyclization is reported. The reaction of 4-(3-aminopyrimido[4,5-d]thieno-2-yl)quinoline-2-ones, which could be obtained from Thorpe-Ziegler isomerization of 4-bromomethylquinoline-2-ones and 5-cyano-1,6-dihydro-4-methyl-2-phenyl-6-thioxopyrimidine,with aromatic aldehydes in the presence of BF3·OEt2 gives pyrimidothieno[1,6]naphthyridines in good yields.展开更多
The title compound, C16H23N5O3S, ethyl 5-amino-1-(5'-methyl-1'-t-butyl-4'-pyrazolyl)carbonyl-3-methylthio- 1H-pyrazole-4-carboxylate (5) has been synthesized by the treatment of ethyl 2-cyano-3,3-dimethylt...The title compound, C16H23N5O3S, ethyl 5-amino-1-(5'-methyl-1'-t-butyl-4'-pyrazolyl)carbonyl-3-methylthio- 1H-pyrazole-4-carboxylate (5) has been synthesized by the treatment of ethyl 2-cyano-3,3-dimethylthioacrylate with 1-t-butyl-5-methyl-4-hydrazinocarbonylpyrazole (4) in refluxed ethanol. The possible mechanism of the above reaction was also discussed. The results of biological test show that the title compound has fungicidal and plant growth regulation activities.展开更多
The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of car...The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of carbohydrates. S. mutans biofilms were generated during a period of 24 h in the following media: Schaedler broth as a control medium containing endogenous glucose, Schaedler broth with an additional 5% sucrose, and Schaedler broth supplemented with 1% xylitol. The confocal laser scanning microscopy(CLSM)-based analyses of the microbial vitality, respiratory activity(5-cyano-2,3-ditolyl tetrazolium chloride, CTC) and production of extracellular polysaccharides(EPS) were performed separately in the inner, middle and outer biofilm layers. In addition to the microbiological sample testing, the glucose/sucrose consumption of the biofilm bacteria was quantified, and the expression of glucosyltransferases and other biofilm-associated genes was investigated. Xylitol exposure did not inhibit the viability of S. mutans biofilms, as monitored by the following experimental parameters: culture growth, vitality, CTC activity and EPS production. However,xylitol exposure caused a difference in gene expression compared to the control. Gtf C was upregulated only in the presence of xylitol.Under xylitol exposure, gtf B was upregulated by a factor of 6, while under sucrose exposure, it was upregulated by a factor of three.Compared with glucose and xylitol, sucrose increased cell vitality in all biofilm layers. In all nutrient media, the intrinsic glucose was almost completely consumed by the cells of the S. mutans biofilm within 24 h. After 24 h of biofilm formation, the multiparametric measurements showed that xylitol in the presence of glucose caused predominantly genotypic differences but did not induce metabolic differences compared to the control. Thus, the availability of dietary carbohydrates in either a pure or combined form seems to affect the cariogenic potential of S. mutans biofilms.展开更多
We have developed simple,cost effective and environmentally benign protocol for the synthesis of 5-substituted 1H-tetrazoles via[2,3]cycloaddition reaction from organic nitriles and sodium azide in glycerol under cata...We have developed simple,cost effective and environmentally benign protocol for the synthesis of 5-substituted 1H-tetrazoles via[2,3]cycloaddition reaction from organic nitriles and sodium azide in glycerol under catalyst free condition.The corresponding 5-substituted 1H-tetrazoles were obtained with good to excellent yields(68-95%).展开更多
A simple method for the cyclocondensation of substituted isoflavones with cyanoacetamide in the presence of sodium hydroxide to give an array of 3-cyano-5,6-diarylpyridin-2(1H)-ones in good yields is reported.
Using factor analysis (principle component) and multiple linear regression methods,4 solute-related structure parameters were selected from 10 structure parameters and the relationships between the retention propertie...Using factor analysis (principle component) and multiple linear regression methods,4 solute-related structure parameters were selected from 10 structure parameters and the relationships between the retention properties (logk’) of 25 2-cyano-3-methylthio-3-substituted amino-acrylates and the 4 parameters were established.There is a good agreement between the observed k’ values and the predicted fe’ values.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.20772088,21172163)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(No.JSSYSXK2010007)
文摘Ga(ClO4)3-catalyzed reaction of 1,2-aryldiamines and α-bromoketones to afford 2-substituted quinoxalines in good yields is described.The reaction proceeded via grinding process with 10%(molar fraction) catalyst under solvent-free conditions at room temperature.For unsymmetrical o-phenylenediamines bearing electron-withdrawing groups,regio-selective quinoxalines were obtained.
基金the Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials for financial support(No.JSKC07041).
文摘A facile procedure for the synthesis of 3-(2′-amino-3′-cyano-4′-arylpyrid-6′-yl) coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out on microwave irradiation in good yield with short time and easy work-up. The structures of all the compounds have been confirmed on the basis of their analytical, IR, ^1H NMR, and mass spectral data.
基金supported by the National Basic Research Program of China(No.2004CB518908)the National High Technology Research and Development Program of China(No.2006AA020601).
文摘A variety of vinamidinium salts were condensated with cyanoacetamide in refluxing methanol that contained sodium methoxide to produce 5-aryl-3-cyano-2-pyridones in good yield. Simple experimental conditions were used to prepare ten different 5-aryl-3- cyano-2-pyridones, four of which are new compounds.C 2009 Song Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金financially supported by the National Natural Science Foundation of China (Nos. 51972258 and 22109186)Open Fund by Sanya Science and Education Innovation Park of Wuhan University of Technology (No. 2021KF0021)supported by 21C Innovation Laboratory,Contemporary Amperex Technology Ltd. by Project No. 21C-OP-202002。
文摘Lithium rich layered oxide(LRLO) has been considered as one of the promising cathodes for lithium-ion batteries(LIBs). The high voltage and large capacity of LRLO depend on Li2MnO_(3)phase. To ameliorate the electrochemical performance of Li2MnO_(3), also written as Li(Li1/3Mn2/3)O_(2), we propose a strategy to substitute Mn4+and Li+in Mn/Li transition metal layer with Ti4+, which can stabilize the structure of Li2MnO_(3)by inhibiting the excessive oxidation of O_(2)-above 4.5 V. More significantly, the unequal-valent substitution brings about the emergence of interlayer Li vacancies, which can promote the Li-ion diffusion based on the enlarged interlayer and increase the capacity by activating the Mn3+/4+redox. We designed Li0.7[Li1/3Mn2/3]0.7Ti0.3O_(2)with high interlayer Li vacancies, which presents a high capacity(290 m Ah/g at 10 m A/g) and stable cycling performance(84% over 60 cycles at 50 m A/g). We predict that this strategy will be helpful to further improve the electrochemical performance of LRLOs.
基金fnancial support from the Research Council of the University of Sistan and Baluchestan
文摘A facile one-pot synthesis of 3,4,5-substituted furan-2(5H)-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using tetra-n-butylammonium bisulfate as a catalyst has been developed.
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the National Natural Science Foundation of China.
文摘Cyclopropanedicarboxylic acid anhydride can be converted to 4-substituted 3-oxabicyclo- [3.1.0]hexan-2-one by reaction with Grignard reagents in ether or tetrahydrofuran solution.
基金SAIF Panjab University for providing analytical facilities for characterization of compounds
文摘A rapid, one-pot and highly efficient protocol for the synthesis of pharmaceutically interesting functionalized 2-amino-3-cyano-4H-pyran and spirooxindole derivatives has been developed using commercially available Cs F as a catalyst in the reaction of malononitrile and aryl aldehydes or isatins with 1,3-cyclohexanediones. The major advantages of this methodology are excellent yield at ambient temperature, very short reaction time(5–10 min), and use of an inexpensive catalyst.
文摘An efficient three-component synthesis of 6-amino-4-aryl-5-cyano-3-metriyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles via a reaction between 3-methyl-1-phenyl-2-pyrazolin-5-one,aromatic aldehydes and malononitrile using tungstate sulfuric acid as a catalyst was described.Mild conditions,good to excellent yields,easily available catalyst and easy work-up are the key features of this method.
文摘An efficient method for the synthesis of novel benzo[b]pyrimido[4′,5′:5,4]thieno[2,3e]-[1,6]naphthyridine-8-one derivatives via Pictet-Spengler cyclization is reported. The reaction of 4-(3-aminopyrimido[4,5-d]thieno-2-yl)quinoline-2-ones, which could be obtained from Thorpe-Ziegler isomerization of 4-bromomethylquinoline-2-ones and 5-cyano-1,6-dihydro-4-methyl-2-phenyl-6-thioxopyrimidine,with aromatic aldehydes in the presence of BF3·OEt2 gives pyrimidothieno[1,6]naphthyridines in good yields.
基金the Natural Science Foundation of Shandong Province (No. Y2003B01), the National Natural Science Foundation of China (No. 20172031) and State Key Laboratory of Applied Organic Chemistry of Lanzhou University.
文摘The title compound, C16H23N5O3S, ethyl 5-amino-1-(5'-methyl-1'-t-butyl-4'-pyrazolyl)carbonyl-3-methylthio- 1H-pyrazole-4-carboxylate (5) has been synthesized by the treatment of ethyl 2-cyano-3,3-dimethylthioacrylate with 1-t-butyl-5-methyl-4-hydrazinocarbonylpyrazole (4) in refluxed ethanol. The possible mechanism of the above reaction was also discussed. The results of biological test show that the title compound has fungicidal and plant growth regulation activities.
基金supported by the National Deutsche Gesellschaft fr Zahnerhaltung-GABA Scientific Fund, Germany
文摘The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of carbohydrates. S. mutans biofilms were generated during a period of 24 h in the following media: Schaedler broth as a control medium containing endogenous glucose, Schaedler broth with an additional 5% sucrose, and Schaedler broth supplemented with 1% xylitol. The confocal laser scanning microscopy(CLSM)-based analyses of the microbial vitality, respiratory activity(5-cyano-2,3-ditolyl tetrazolium chloride, CTC) and production of extracellular polysaccharides(EPS) were performed separately in the inner, middle and outer biofilm layers. In addition to the microbiological sample testing, the glucose/sucrose consumption of the biofilm bacteria was quantified, and the expression of glucosyltransferases and other biofilm-associated genes was investigated. Xylitol exposure did not inhibit the viability of S. mutans biofilms, as monitored by the following experimental parameters: culture growth, vitality, CTC activity and EPS production. However,xylitol exposure caused a difference in gene expression compared to the control. Gtf C was upregulated only in the presence of xylitol.Under xylitol exposure, gtf B was upregulated by a factor of 6, while under sucrose exposure, it was upregulated by a factor of three.Compared with glucose and xylitol, sucrose increased cell vitality in all biofilm layers. In all nutrient media, the intrinsic glucose was almost completely consumed by the cells of the S. mutans biofilm within 24 h. After 24 h of biofilm formation, the multiparametric measurements showed that xylitol in the presence of glucose caused predominantly genotypic differences but did not induce metabolic differences compared to the control. Thus, the availability of dietary carbohydrates in either a pure or combined form seems to affect the cariogenic potential of S. mutans biofilms.
基金support from Department of Atomic Energy-Board of Research in Nuclear Sciences(DAE-BRNS)(No2009/37/39/BRNS/2268)
文摘We have developed simple,cost effective and environmentally benign protocol for the synthesis of 5-substituted 1H-tetrazoles via[2,3]cycloaddition reaction from organic nitriles and sodium azide in glycerol under catalyst free condition.The corresponding 5-substituted 1H-tetrazoles were obtained with good to excellent yields(68-95%).
文摘A simple method for the cyclocondensation of substituted isoflavones with cyanoacetamide in the presence of sodium hydroxide to give an array of 3-cyano-5,6-diarylpyridin-2(1H)-ones in good yields is reported.
文摘Using factor analysis (principle component) and multiple linear regression methods,4 solute-related structure parameters were selected from 10 structure parameters and the relationships between the retention properties (logk’) of 25 2-cyano-3-methylthio-3-substituted amino-acrylates and the 4 parameters were established.There is a good agreement between the observed k’ values and the predicted fe’ values.