A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H2O2/HCl system in ethanol at room temperature is d...A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H2O2/HCl system in ethanol at room temperature is described. The target compounds have been characterized by ^1H NMR, ^13C NMR, IR and MS. Short reaction time, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure.展开更多
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
Proceeding from natural amino acid L-asparagine and commercially available aldehydes a stereoselective synthesis was developed of (2S,4S)-2-alkyl(aryl)-3-(3-sulfanylpropanoyl)-6-oxohexahy- dropyrimidine-4-carboxylic a...Proceeding from natural amino acid L-asparagine and commercially available aldehydes a stereoselective synthesis was developed of (2S,4S)-2-alkyl(aryl)-3-(3-sulfanylpropanoyl)-6-oxohexahy- dropyrimidine-4-carboxylic acids, potential antihypertensive drugs, inhibitors of the angiotensin converting enzyme.展开更多
2-Substituted-2,3-dihydro-4（1H）-quinazolinones were synthesized in high yield by condensation of 2-anthranilamide with aromatic aldehydes or ketones in refluxing water without catalyst.This protocol has advantages o...2-Substituted-2,3-dihydro-4（1H）-quinazolinones were synthesized in high yield by condensation of 2-anthranilamide with aromatic aldehydes or ketones in refluxing water without catalyst.This protocol has advantages of high yield,simple work-up and environmental friendly procedure.展开更多
A series of 2,3-dihydroquinazolin-4（1H）-ones have been synthesized in good to excellent yields through direct cyclocondensation of anthranilamide and aryl aldehydes or ketones in water or methanol under mild conditi...A series of 2,3-dihydroquinazolin-4（1H）-ones have been synthesized in good to excellent yields through direct cyclocondensation of anthranilamide and aryl aldehydes or ketones in water or methanol under mild conditions.The reaction was efficiently promoted by 10 mol%sulfamic acid（SA,H_2NSO_3H） and the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity.展开更多
1,1,1,-Trifluoro-2- substituted- phenyl- 2- propanols- 3- 14C were prepared from addition of methyl- 14C magnesium iodide to appropriate trifluoroacetophenone. These alcohols were converted into tosylatcs by reaction ...1,1,1,-Trifluoro-2- substituted- phenyl- 2- propanols- 3- 14C were prepared from addition of methyl- 14C magnesium iodide to appropriate trifluoroacetophenone. These alcohols were converted into tosylatcs by reaction with n-butyllithium and then with p-toluenesulfonyl chloride. The yield, boiling point or melting point and pertinent spectral data of these compounds are reported.展开更多
The reaction of imidazole-2-thione derivative 1 with 2-chloro-N-p-tolylacetamide afforded the corresponding 2-(1HI-imidazol-2-ylthio)-N-p-tolylacetamide 2. Reaction compound 2 with different reagents such as p-chlorob...The reaction of imidazole-2-thione derivative 1 with 2-chloro-N-p-tolylacetamide afforded the corresponding 2-(1HI-imidazol-2-ylthio)-N-p-tolylacetamide 2. Reaction compound 2 with different reagents such as p-chlorobenzaldehyde and p-chlorophenyl diazonium chloride afforded the corresponding arylidene derivative 3 and hydrazone derivative 6. Reactions of 2 with carbon disulfide in dimethylformamide (DMF) in one equivalent potassium hydroxide afforded intermediate potassium sulphide salt 8, which treatment with dilute hydrochloric acid and phenacyl bromide afforded the corresponding 2-[p-tolylcarbamoyl]ethanedithioic acid 9 and 3-[benzo-ylmethylthio]-N-p-tolyl-3-thioxo-propaneamide 10. While the reaction 2 with carbon disulphide in the presence of two equivalent potassium hydroxide in DMF gave non-isolated potassium salt 11, which was allowed to react with halogenated compounds namely ethyl chloroacetate and methyl iodide afforded the corresponding 3, 3-bis[(ethoxycarbonyl)methylthio]-N-p-tolylacrylamide 12 and 3,3-bis-(methylthio)-N-p-tolylacrylamide 13 respectively. Reaction 2 with phenyl isothiocyanate in basic DMF yielded the intermediate potassium sulphide salt 18. Acidification 18 with dilute hydro-chloric acid afforded the corresponding thiocarbamoyl derivative 19. Treatment of intermediate 18 with methyl iodide, phenacyl bromide and ethylchloroacetate afforded the 3-anilino-3-(methylthio)-N-p-tolylacrylamide 20, 2-(1,3-thiazol-2(3H)-ylidene)-N-p-tolylacetamide 21 and 2-(4-oxo-3-phenyl-1,3-thiazolidin-2-ylidene)-N-p-tolylacetamide 22 respectively. The structure of the newly synthesized compounds has been confirmed by elemental analysis and spectra data. Synthesized compounds 2, 3, 6, 13, 15a, 15b, 17, 20, 21, 22 and 23 were screened for their antibacterial activities in vitro against Gram-positive (Staphylococcus aureus and Bacillus subtilis), Gram-negative (Pseudomonas aeuroginosa and Escherichia coli ) and antifungal activities against (Aspergillus fumigates, Syncephalastrum racemosum, Geotrichum candidum and Candida albicans).展开更多
Four components have been reacted in water and in the presence of N-morpholine yielded pyrnopyrazole as a simple substrate for novel N2-acyclonucleoside derivatives of fused pyranopyrazole. The sodium salt of fused py...Four components have been reacted in water and in the presence of N-morpholine yielded pyrnopyrazole as a simple substrate for novel N2-acyclonucleoside derivatives of fused pyranopyrazole. The sodium salt of fused pyranopyrazole reacted with halo alcohols led to the formation of new scaffolds from fused pyranopyrazole derivatives. All newly prepared compounds are characterized spectroscopically.展开更多
Cp_(2)TiCl_(2) as a Lewis acid precursor and nicotinic acid as a ligand have been used synergistically for the one-pot synthesis of 2-(N-substituted amino)-1,4-naphthoquinones.This method establishes a general strateg...Cp_(2)TiCl_(2) as a Lewis acid precursor and nicotinic acid as a ligand have been used synergistically for the one-pot synthesis of 2-(N-substituted amino)-1,4-naphthoquinones.This method establishes a general strategy for the functionalization and conversion of C-H bonds of 1,4-naphthoquinones into C-N bonds,providing an effective route to synthesize 2-(N-substituted amino)-1,4-naphthoquinone with high yield under mild conditions.Additionally,the synergistic catalytic mechanism was investigated by 1H NMR titration experiments and LC-MS analysis,with experimental results sufficiently and consistently supporting the proposed mechanism of the catalytic cycle.展开更多
Here,1D bis(N-carboxymethyl)peryleneimide(H_(2)PDI),0D 1,6,7,12-tetrachloro-bis(N-carboxymethyl)peryleneimide(4Cl-H_(2)PDI),and 2D 4Cl-H_(2)PDI/graphene quantum dot(4Cl-H_(2)PDI/GQD)nanostructures are synthesized and ...Here,1D bis(N-carboxymethyl)peryleneimide(H_(2)PDI),0D 1,6,7,12-tetrachloro-bis(N-carboxymethyl)peryleneimide(4Cl-H_(2)PDI),and 2D 4Cl-H_(2)PDI/graphene quantum dot(4Cl-H_(2)PDI/GQD)nanostructures are synthesized and carefully analyzed.The effect of bay-/end-substitution and S-scheme heterojunction of PDI-based materials as main catalysts on the photocatalytic H_(2)O_(2)evolution is first studied through the oxygen reduction reaction(ORR).Under the visible-light irradiation(>420 nm),4Cl-H_(2)PDI and 4Cl-H_(2)PDI/GQD as photocatalysts exhibit the∼7 and∼16 times H_(2)O_(2)evolution rate than H_(2)PDI(1059.6 vs.2484.0 vs.160.0μM g^(−1) h^(−1)),respectively.The systematical experiments reveal that 4Cl-H_(2)PDI and 4Cl-H_(2)PDI/GQD should prefer a two-step single-electron ORR process,while H_(2)PDI may involve a 4e-water oxidation and one-step 2e-ORR process.Further experiments confirm that the bay-substitution and GQD doping of H_(2)PDI can promote the generation,transportation,and separation of photogenerated electrons and holes,and prolong the carrier lifetime.This work provides insight into PDI-based photocatalytic H_(2)O_(2)production.展开更多
Carbon dioxide hydrogenation to gasoline can effectively alleviate the energy crisis and benefit the global environment.Owing to its orthogonally connected nanosheet configuration,large pore volume,and appropriate thi...Carbon dioxide hydrogenation to gasoline can effectively alleviate the energy crisis and benefit the global environment.Owing to its orthogonally connected nanosheet configuration,large pore volume,and appropriate thickness of single nanosheet,self-pillared pentasil(SPP)nanosheet zeolite is integrated with In_(2)O_(3)-ZrO_(2)as a tandem catalyst for CO_(2)hydrogenation to C_(5+)hydrocarbons.By substituting Al in the SPP framework with Ga,the acid strength of SPP is reduced,and acid density is increased,which favors the generation of C_(5+)hydrocarbons and enhances the cracking resistance of long-chain hydrocarbons.A maximum C_(5+)hydrocarbon selectivity of 82%was obtained on In_(2)O_(3)-ZrO_(2)/Ga-SPP(Si/Ga=100),which shows no deactivation after 200 h reaction time.Furthermore,introducing Pd into the In_(2)O_(3)-ZrO_(2)not only boosts CO_(2)conversion to 11%but also suppresses methane selectivity to below 1%.This study offers valuable insights into the design of highly active CO_(2)-to-gasoline catalysts by leveraging the distinctive structure and acidity of zeolites within the tandem catalyst systems.展开更多
Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials ...Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials for ASIBs,Na_(3)V_(2)(PO_(4))_(3)(NVP) exhibits excellent structural stability and a high Na+diffusion coefficient,making it a promising option.However,the high solubility of vanadium-based materials in aqueous electrolytes engenders suboptimal cycling stability for Na_(3)V_(2)(PO_(4))_(3),constraining its application in ASIBs.Herein,the Cr-substituted Na_(3)V_(1.3)Cr_(0.7)(PO_(4))3@C(NV_(1.3)Cr_(0.7)P) cathode material was synthesized via a simple sol-gel method.It is found that Cr substitution reduces the cell parameters of NV_(1.3)Cr_(0.7)P,effectively reinforcing the crystal structure.Furthermore,NV_(1.3)Cr_(0.7)P alters the Na^(+)insertion/extraction mechanism,transforming the typical two-phase reaction between Na_(1)V_(2)(PO_(4))_(3)and Na_(3)V_(2)(PO_(4))3into continuous solid-solution reactions with stable intermediates.The Cr substitution diminishes the sodium-ion diffusion energy barrier in NV_(1.3)Cr_(0.7)P,leading to smoother Na+insertion and extraction processes.Consequently,NV_(1.3)Cr_(0.7)P exhibits impressive cycling stability,retaining 74.8% of its capacity after 5,000 cycles at a current density of 5 A g^(-1),along with an outstanding rate performance of 79,2% at 10 A g^(-1).This work elucidates the stable Na^(+)insertion/extraction processes in Cr-substituted NV_(1.3)Cr_(0.7)P,offering insights into the application of vanadium-based materials in aqueous sodium-ion batteries.展开更多
An efficient synthesis of 2-substituted benzoxazoles through RuCl3·3H2O catalyzed, air oxidized tandem reactions of 2-aminophenols and aldehydes in [bmim]BF4 was developed. This synthetic strategy has such advant...An efficient synthesis of 2-substituted benzoxazoles through RuCl3·3H2O catalyzed, air oxidized tandem reactions of 2-aminophenols and aldehydes in [bmim]BF4 was developed. This synthetic strategy has such advantages as mild reaction conditions, cost-free oxidant, readily available starting materials, and recyclable catalyst and solvent. As an application, it was successfully used in the synthesis of the unreported 5-（benzoxazol-2-yl）-2＇-deoxyuridines with potential biological activities.展开更多
A novel and efficient approach to the synthesis of 2-substituted benzimidazoles has been developed via CuI/DMEDA-catalyzed coupling reaction and post-cyclization with glacial acetic acid from readily available 2-iodoa...A novel and efficient approach to the synthesis of 2-substituted benzimidazoles has been developed via CuI/DMEDA-catalyzed coupling reaction and post-cyclization with glacial acetic acid from readily available 2-iodoanilines and amides. This method is suitable for the construction of a variety of benzimidazoles in moderate to good yields under short reaction times.展开更多
Asymmetric hydrogenation of tetrasubstituted alkenes is an important but challenging research topic.Herein,we report an efficient iridium-catalyzed asymmetric hydrogenation of tetrasubstituted α,β-unsaturated ketone...Asymmetric hydrogenation of tetrasubstituted alkenes is an important but challenging research topic.Herein,we report an efficient iridium-catalyzed asymmetric hydrogenation of tetrasubstituted α,β-unsaturated ketones for the synthesis of chiral 2-substituted cyclopentyl aryl ketones,an important chiral structural motif for the preparation of chiral pharmaceuticals and bioactive molecules.The reaction proceeded very well with good functional group compatibility and delivered the hydrogenated products in high yields and stereoselectivities(up to 99% yield,>20:1 dr and 99%ee).In addition,the reaction could be carried out on a gram-scale,and all four stereoisomers of the hydrogenated products bearing two contiguous stereocenters were obtained.Furthermore,the hydrogenated product can be transformed into the ERβ agonist Erteberel,and the reaction pathway was also studied via deuterium-labelling experiments.展开更多
基金Education Department of Zhejiang Province(No.20060811) for the financial support of this work.
文摘A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H2O2/HCl system in ethanol at room temperature is described. The target compounds have been characterized by ^1H NMR, ^13C NMR, IR and MS. Short reaction time, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure.
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.
文摘Proceeding from natural amino acid L-asparagine and commercially available aldehydes a stereoselective synthesis was developed of (2S,4S)-2-alkyl(aryl)-3-(3-sulfanylpropanoyl)-6-oxohexahy- dropyrimidine-4-carboxylic acids, potential antihypertensive drugs, inhibitors of the angiotensin converting enzyme.
文摘2-Substituted-2,3-dihydro-4（1H）-quinazolinones were synthesized in high yield by condensation of 2-anthranilamide with aromatic aldehydes or ketones in refluxing water without catalyst.This protocol has advantages of high yield,simple work-up and environmental friendly procedure.
文摘A series of 2,3-dihydroquinazolin-4（1H）-ones have been synthesized in good to excellent yields through direct cyclocondensation of anthranilamide and aryl aldehydes or ketones in water or methanol under mild conditions.The reaction was efficiently promoted by 10 mol%sulfamic acid（SA,H_2NSO_3H） and the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity.
基金The Project Supported by the National Science Foundation of U.S.A.
文摘1,1,1,-Trifluoro-2- substituted- phenyl- 2- propanols- 3- 14C were prepared from addition of methyl- 14C magnesium iodide to appropriate trifluoroacetophenone. These alcohols were converted into tosylatcs by reaction with n-butyllithium and then with p-toluenesulfonyl chloride. The yield, boiling point or melting point and pertinent spectral data of these compounds are reported.
文摘The reaction of imidazole-2-thione derivative 1 with 2-chloro-N-p-tolylacetamide afforded the corresponding 2-(1HI-imidazol-2-ylthio)-N-p-tolylacetamide 2. Reaction compound 2 with different reagents such as p-chlorobenzaldehyde and p-chlorophenyl diazonium chloride afforded the corresponding arylidene derivative 3 and hydrazone derivative 6. Reactions of 2 with carbon disulfide in dimethylformamide (DMF) in one equivalent potassium hydroxide afforded intermediate potassium sulphide salt 8, which treatment with dilute hydrochloric acid and phenacyl bromide afforded the corresponding 2-[p-tolylcarbamoyl]ethanedithioic acid 9 and 3-[benzo-ylmethylthio]-N-p-tolyl-3-thioxo-propaneamide 10. While the reaction 2 with carbon disulphide in the presence of two equivalent potassium hydroxide in DMF gave non-isolated potassium salt 11, which was allowed to react with halogenated compounds namely ethyl chloroacetate and methyl iodide afforded the corresponding 3, 3-bis[(ethoxycarbonyl)methylthio]-N-p-tolylacrylamide 12 and 3,3-bis-(methylthio)-N-p-tolylacrylamide 13 respectively. Reaction 2 with phenyl isothiocyanate in basic DMF yielded the intermediate potassium sulphide salt 18. Acidification 18 with dilute hydro-chloric acid afforded the corresponding thiocarbamoyl derivative 19. Treatment of intermediate 18 with methyl iodide, phenacyl bromide and ethylchloroacetate afforded the 3-anilino-3-(methylthio)-N-p-tolylacrylamide 20, 2-(1,3-thiazol-2(3H)-ylidene)-N-p-tolylacetamide 21 and 2-(4-oxo-3-phenyl-1,3-thiazolidin-2-ylidene)-N-p-tolylacetamide 22 respectively. The structure of the newly synthesized compounds has been confirmed by elemental analysis and spectra data. Synthesized compounds 2, 3, 6, 13, 15a, 15b, 17, 20, 21, 22 and 23 were screened for their antibacterial activities in vitro against Gram-positive (Staphylococcus aureus and Bacillus subtilis), Gram-negative (Pseudomonas aeuroginosa and Escherichia coli ) and antifungal activities against (Aspergillus fumigates, Syncephalastrum racemosum, Geotrichum candidum and Candida albicans).
文摘Four components have been reacted in water and in the presence of N-morpholine yielded pyrnopyrazole as a simple substrate for novel N2-acyclonucleoside derivatives of fused pyranopyrazole. The sodium salt of fused pyranopyrazole reacted with halo alcohols led to the formation of new scaffolds from fused pyranopyrazole derivatives. All newly prepared compounds are characterized spectroscopically.
基金2024 Special Talent Introduction Projects of Key R&D Program of Ningxia Hui Autonomous Region(2024BEH04049)the 2024 Guyuan City Innovation-Driven Achievement Transformation Project(2024BGTYF01-47)2025 Ningxia Natural Science Foundation Program(2025AAC030624).
文摘Cp_(2)TiCl_(2) as a Lewis acid precursor and nicotinic acid as a ligand have been used synergistically for the one-pot synthesis of 2-(N-substituted amino)-1,4-naphthoquinones.This method establishes a general strategy for the functionalization and conversion of C-H bonds of 1,4-naphthoquinones into C-N bonds,providing an effective route to synthesize 2-(N-substituted amino)-1,4-naphthoquinone with high yield under mild conditions.Additionally,the synergistic catalytic mechanism was investigated by 1H NMR titration experiments and LC-MS analysis,with experimental results sufficiently and consistently supporting the proposed mechanism of the catalytic cycle.
基金support of the Fujian Science&Technol-ogy Innovation Laboratory for Optoelectronic Information of China(No.2021ZR124)the National Natural Science Foundation of China(No.21705150).
文摘Here,1D bis(N-carboxymethyl)peryleneimide(H_(2)PDI),0D 1,6,7,12-tetrachloro-bis(N-carboxymethyl)peryleneimide(4Cl-H_(2)PDI),and 2D 4Cl-H_(2)PDI/graphene quantum dot(4Cl-H_(2)PDI/GQD)nanostructures are synthesized and carefully analyzed.The effect of bay-/end-substitution and S-scheme heterojunction of PDI-based materials as main catalysts on the photocatalytic H_(2)O_(2)evolution is first studied through the oxygen reduction reaction(ORR).Under the visible-light irradiation(>420 nm),4Cl-H_(2)PDI and 4Cl-H_(2)PDI/GQD as photocatalysts exhibit the∼7 and∼16 times H_(2)O_(2)evolution rate than H_(2)PDI(1059.6 vs.2484.0 vs.160.0μM g^(−1) h^(−1)),respectively.The systematical experiments reveal that 4Cl-H_(2)PDI and 4Cl-H_(2)PDI/GQD should prefer a two-step single-electron ORR process,while H_(2)PDI may involve a 4e-water oxidation and one-step 2e-ORR process.Further experiments confirm that the bay-substitution and GQD doping of H_(2)PDI can promote the generation,transportation,and separation of photogenerated electrons and holes,and prolong the carrier lifetime.This work provides insight into PDI-based photocatalytic H_(2)O_(2)production.
基金financially supported by the National Key Research and Development Program of China(2024YFB4105401)the National Natural Science Foundation of China(22472017)+1 种基金the Liaoning Binhai Laboratory(LBLG-2024-06)the Fundamental Research Funds for the Central Universities(DUT22LAB602and DUT24RC(3)071)。
文摘Carbon dioxide hydrogenation to gasoline can effectively alleviate the energy crisis and benefit the global environment.Owing to its orthogonally connected nanosheet configuration,large pore volume,and appropriate thickness of single nanosheet,self-pillared pentasil(SPP)nanosheet zeolite is integrated with In_(2)O_(3)-ZrO_(2)as a tandem catalyst for CO_(2)hydrogenation to C_(5+)hydrocarbons.By substituting Al in the SPP framework with Ga,the acid strength of SPP is reduced,and acid density is increased,which favors the generation of C_(5+)hydrocarbons and enhances the cracking resistance of long-chain hydrocarbons.A maximum C_(5+)hydrocarbon selectivity of 82%was obtained on In_(2)O_(3)-ZrO_(2)/Ga-SPP(Si/Ga=100),which shows no deactivation after 200 h reaction time.Furthermore,introducing Pd into the In_(2)O_(3)-ZrO_(2)not only boosts CO_(2)conversion to 11%but also suppresses methane selectivity to below 1%.This study offers valuable insights into the design of highly active CO_(2)-to-gasoline catalysts by leveraging the distinctive structure and acidity of zeolites within the tandem catalyst systems.
基金financially supported by the Scientific and Technological Plan Project of Guizhou Province ([2024]054)Additional support came from the Industry and Education Combination Innovation Platform of Intelligent Manufacturing and Graduate Joint Training Base at Guizhou University (2020-520000-83-01324061)the Guizhou Engineering Research Center for Smart Services (2203-520102-04-04-298868)。
文摘Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials for ASIBs,Na_(3)V_(2)(PO_(4))_(3)(NVP) exhibits excellent structural stability and a high Na+diffusion coefficient,making it a promising option.However,the high solubility of vanadium-based materials in aqueous electrolytes engenders suboptimal cycling stability for Na_(3)V_(2)(PO_(4))_(3),constraining its application in ASIBs.Herein,the Cr-substituted Na_(3)V_(1.3)Cr_(0.7)(PO_(4))3@C(NV_(1.3)Cr_(0.7)P) cathode material was synthesized via a simple sol-gel method.It is found that Cr substitution reduces the cell parameters of NV_(1.3)Cr_(0.7)P,effectively reinforcing the crystal structure.Furthermore,NV_(1.3)Cr_(0.7)P alters the Na^(+)insertion/extraction mechanism,transforming the typical two-phase reaction between Na_(1)V_(2)(PO_(4))_(3)and Na_(3)V_(2)(PO_(4))3into continuous solid-solution reactions with stable intermediates.The Cr substitution diminishes the sodium-ion diffusion energy barrier in NV_(1.3)Cr_(0.7)P,leading to smoother Na+insertion and extraction processes.Consequently,NV_(1.3)Cr_(0.7)P exhibits impressive cycling stability,retaining 74.8% of its capacity after 5,000 cycles at a current density of 5 A g^(-1),along with an outstanding rate performance of 79,2% at 10 A g^(-1).This work elucidates the stable Na^(+)insertion/extraction processes in Cr-substituted NV_(1.3)Cr_(0.7)P,offering insights into the application of vanadium-based materials in aqueous sodium-ion batteries.
基金Project supported by the National Natural Science Foundation of China （Nos. 20772025, 20972042）, Innovation Scientists and Technicians Troop Construction Projects of Henan Province （No. 104100510019）, and the Natural Science Foundation of Henan Province （No. 092300410237）.
文摘An efficient synthesis of 2-substituted benzoxazoles through RuCl3·3H2O catalyzed, air oxidized tandem reactions of 2-aminophenols and aldehydes in [bmim]BF4 was developed. This synthetic strategy has such advantages as mild reaction conditions, cost-free oxidant, readily available starting materials, and recyclable catalyst and solvent. As an application, it was successfully used in the synthesis of the unreported 5-（benzoxazol-2-yl）-2＇-deoxyuridines with potential biological activities.
基金Acknowledgement We are grateful for support of this project by the National Natural Science Foundation of China （No. J1103307） and the project of Science Foundation of Gansu Province （No. 1208RJZA266）.
文摘A novel and efficient approach to the synthesis of 2-substituted benzimidazoles has been developed via CuI/DMEDA-catalyzed coupling reaction and post-cyclization with glacial acetic acid from readily available 2-iodoanilines and amides. This method is suitable for the construction of a variety of benzimidazoles in moderate to good yields under short reaction times.
基金supported by the National Key R&D Program of China(No.2018YFE0126800)the National Natural Science Foundation of China(Nos.21991112 and 22001164)the Shanghai Pujiang Program(20PJ1406400).
文摘Asymmetric hydrogenation of tetrasubstituted alkenes is an important but challenging research topic.Herein,we report an efficient iridium-catalyzed asymmetric hydrogenation of tetrasubstituted α,β-unsaturated ketones for the synthesis of chiral 2-substituted cyclopentyl aryl ketones,an important chiral structural motif for the preparation of chiral pharmaceuticals and bioactive molecules.The reaction proceeded very well with good functional group compatibility and delivered the hydrogenated products in high yields and stereoselectivities(up to 99% yield,>20:1 dr and 99%ee).In addition,the reaction could be carried out on a gram-scale,and all four stereoisomers of the hydrogenated products bearing two contiguous stereocenters were obtained.Furthermore,the hydrogenated product can be transformed into the ERβ agonist Erteberel,and the reaction pathway was also studied via deuterium-labelling experiments.
