α,β-unsaturated acyl-substituted imido derivatives are a kind of important electron-deficient alkenes and widely applied in synthesis.In this paper,a new synthetic method of these alkenes is developed and the cataly...α,β-unsaturated acyl-substituted imido derivatives are a kind of important electron-deficient alkenes and widely applied in synthesis.In this paper,a new synthetic method of these alkenes is developed and the catalytic mechanism is discussed.With LiCl as the catalyst,the products are synthesized with succinimides or phthalimide、crotonic anhydride in the present of triethylamine at low temperature.The reactions proceed smoothly in the given condition with good yields.展开更多
Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated ...Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated for the case of selective alkylarene oxidation by molecular oxygen.The proposed catalytic system consists of two widely available components:N-hydroxyphthalimide(NHPI,a homogeneous organocatalyst for free-radical chain reactions)and nanosized TiO_(2)(heterogeneous UV-active photoredox catalyst).The interaction of NHPI with TiO_(2) allows for a shift from UV to visible light photoredox activity and generation of phthalimide-N-oxyl(PINO)radicals that diffuse into the solution where NHPI/PINO-catalyzed free-radical chain reaction can proceed without the additional light input providing a fundamental increase in energy efficiency.The NHPI/TiO_(2) ratio controls the selectivity of oxidation affording preferential formation of hydroperoxide or ketone from alkylarene.展开更多
The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-...The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-toluic acid (PTA) were investigated. The results showed that the existing synergistic action in the catalytic oxidation can shorten the induction period of the radical reaction and improve the yield of PTA.展开更多
Shirota's kinetic model and our kinetic model were used to treat the kinetic data of styrene (St) and N-phenylmaleimide (PMI) copolymerization in which charge-transfer complex (CTC) was formed. The results obtaine...Shirota's kinetic model and our kinetic model were used to treat the kinetic data of styrene (St) and N-phenylmaleimide (PMI) copolymerization in which charge-transfer complex (CTC) was formed. The results obtained by Shirota's kinetic model were disagreed with the experiments and the experimental phenomena could not be explained. The kinetic data of all feed fractions can be treated with our kinetic model, and the experimental phenomena can be explained from the propagation constants and reactivity ratios. Our kinetic model is also suitable for the kinetic data of methyl methacrylate (MMA) and PMI copolymerization in which CTC can not be formed.展开更多
In this paper a modified two-step procedure for synthesis of N-（1-naphthyl） suecinimide （NaS） was developed, and the molecular structure of NaS was properly characterized by XRD, FT-IR, 1H NMR, DSC, etc. The resul...In this paper a modified two-step procedure for synthesis of N-（1-naphthyl） suecinimide （NaS） was developed, and the molecular structure of NaS was properly characterized by XRD, FT-IR, 1H NMR, DSC, etc. The results show that the melting point of our product is 159 ℃-160.5 ℃, and the characteristic infrared absorption band of carbonyl group splits into two peaks （1705cm^-3/1779cm^-3）, which are found to be quite different from the documented data （rap 147℃ -149℃; IR C=0-1700cm^-3）. Besides, photophysical spectroscopy was found to be powerful to study the molecular structure and crystal morphology of NaS compound.展开更多
A series of N-substituted （Z）-3-（（2-benzyl）-4-oxopent-2-yl）pyrrole-2,5-diones were synthesized and characterized. The compounds were synthesized from dimethyl-2-（（Z）-2-（benzylamino）-4-oxopent-2-en-3-yl） fu...A series of N-substituted （Z）-3-（（2-benzyl）-4-oxopent-2-yl）pyrrole-2,5-diones were synthesized and characterized. The compounds were synthesized from dimethyl-2-（（Z）-2-（benzylamino）-4-oxopent-2-en-3-yl） fumarate （9） and dimethyl acetylenedi-carboxylate followed by reaction with some amines in refluxing ethanol. The identification of the compounds were based on spectroscopic analysis such as 1R （infrared）, UV （ultraviolet）, ^1H-NMR （nuclear magnetic resonance） and the microanalysis of the elements （CHN （microanalysis）） data.展开更多
N-(5-phenylseleno)pentyl succinimide 1, C15H19NO2Se (Mr = 324.27), was prepared by treating Br(CH2)5SePh with potassium succinimide. Its crystal structure has been determined by X-ray single-crystal diffraction. The c...N-(5-phenylseleno)pentyl succinimide 1, C15H19NO2Se (Mr = 324.27), was prepared by treating Br(CH2)5SePh with potassium succinimide. Its crystal structure has been determined by X-ray single-crystal diffraction. The crystal of 1 belongs to monoclinic system, space group P21/c with the crystal cell parameters: a = 18.018(6), b = 5.980(2), c = 14.682(5) ? = 109.977(6)? V = 1486.7(9) 3, Z = 4, Dc = 1.449 g/cm3, (MoK? = 2.523 mm-1, F(000) = 664,the final R = 0.0302 and wR = 0.0666 for 2623 independent observed reflections with I > 2(I). Structure analyses revealed that there exist strong nonclassical hydrogen bonds (CH…O).展开更多
A novel strategy for site-selective benzylic C–H oxidation has been developed through mediated electrolysis.A bulky maleimide N-oxyl radical(MINO)generated by proton-coupled electrochemical oxidation of N-hydroxymale...A novel strategy for site-selective benzylic C–H oxidation has been developed through mediated electrolysis.A bulky maleimide N-oxyl radical(MINO)generated by proton-coupled electrochemical oxidation of N-hydroxymaleimide(NHMI),serves as a hydrogen atom-transfer mediator.Good-to-excellent site selectivity was observed among different substrates,providing a practical approach for site-selective benzylic C–H oxidation.Additionally,the hydrogen-atom transfer mechanism for C–H electrochemical oxidation allows the oxidation to proceed at much lower anode potentials relative to direct electrolysis and with minimal reliance on the substrate's electronic properties.展开更多
Aim To synthesize the tripepide Weinreb amide Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) as a useful precursor of aspartyl peptide aldehyde derivatives; Methods DCC, IBCF method was used for preparation of ...Aim To synthesize the tripepide Weinreb amide Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) as a useful precursor of aspartyl peptide aldehyde derivatives; Methods DCC, IBCF method was used for preparation of Weinreb amide; N hydroxysuccinimide activated ester was used in peptide synthesis; and Boc as N protecting group of amino acid. Results Boc Asp(OBzl) N(OMe)Me (3), Boc β Ala Asp(OBzl) N(OMe)Me (5), and Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) were synthesized successfully. Conclusion An useful precursor of tripeptide aspartyl aldehydes was synthesized.展开更多
Terephthalic acid(PTA) is practically one of the main materials of polyester. Its corresponding solid-liquid equilibrium data will provide essential support for industry design and further theoretical studies. In this...Terephthalic acid(PTA) is practically one of the main materials of polyester. Its corresponding solid-liquid equilibrium data will provide essential support for industry design and further theoretical studies. In this work,solid-liquid equilibriums of terephthalic acid in four solvents, N,N-dimethylformamide, N,N-dimethylacetamide,dimethylsulphoxide and N-methyl-2-ketopyrrolidene, were determined in the temperature range from 293.15 K to 364.6 K by dynamic method. All these data were regressed by λh model, Wilson model and NRTL model, average absolute relative deviations of which are 1.25%, 15.02% and 7.22% respectively. It indicates that λh model is mostsuitable for description of the solid-liquid equilibrium containing PTA.展开更多
文摘α,β-unsaturated acyl-substituted imido derivatives are a kind of important electron-deficient alkenes and widely applied in synthesis.In this paper,a new synthetic method of these alkenes is developed and the catalytic mechanism is discussed.With LiCl as the catalyst,the products are synthesized with succinimides or phthalimide、crotonic anhydride in the present of triethylamine at low temperature.The reactions proceed smoothly in the given condition with good yields.
文摘Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated for the case of selective alkylarene oxidation by molecular oxygen.The proposed catalytic system consists of two widely available components:N-hydroxyphthalimide(NHPI,a homogeneous organocatalyst for free-radical chain reactions)and nanosized TiO_(2)(heterogeneous UV-active photoredox catalyst).The interaction of NHPI with TiO_(2) allows for a shift from UV to visible light photoredox activity and generation of phthalimide-N-oxyl(PINO)radicals that diffuse into the solution where NHPI/PINO-catalyzed free-radical chain reaction can proceed without the additional light input providing a fundamental increase in energy efficiency.The NHPI/TiO_(2) ratio controls the selectivity of oxidation affording preferential formation of hydroperoxide or ketone from alkylarene.
基金supported by the National Natural Science Foundation of China(Grant No.20072025).
文摘The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-toluic acid (PTA) were investigated. The results showed that the existing synergistic action in the catalytic oxidation can shorten the induction period of the radical reaction and improve the yield of PTA.
基金Supported by the Doctoral Foundation of the Education Commission of China.
文摘Shirota's kinetic model and our kinetic model were used to treat the kinetic data of styrene (St) and N-phenylmaleimide (PMI) copolymerization in which charge-transfer complex (CTC) was formed. The results obtained by Shirota's kinetic model were disagreed with the experiments and the experimental phenomena could not be explained. The kinetic data of all feed fractions can be treated with our kinetic model, and the experimental phenomena can be explained from the propagation constants and reactivity ratios. Our kinetic model is also suitable for the kinetic data of methyl methacrylate (MMA) and PMI copolymerization in which CTC can not be formed.
基金Natural Science Foundation of China (50273014, 29928003)Natural Science Foundation of Tianjin (03380261).
文摘In this paper a modified two-step procedure for synthesis of N-（1-naphthyl） suecinimide （NaS） was developed, and the molecular structure of NaS was properly characterized by XRD, FT-IR, 1H NMR, DSC, etc. The results show that the melting point of our product is 159 ℃-160.5 ℃, and the characteristic infrared absorption band of carbonyl group splits into two peaks （1705cm^-3/1779cm^-3）, which are found to be quite different from the documented data （rap 147℃ -149℃; IR C=0-1700cm^-3）. Besides, photophysical spectroscopy was found to be powerful to study the molecular structure and crystal morphology of NaS compound.
文摘A series of N-substituted （Z）-3-（（2-benzyl）-4-oxopent-2-yl）pyrrole-2,5-diones were synthesized and characterized. The compounds were synthesized from dimethyl-2-（（Z）-2-（benzylamino）-4-oxopent-2-en-3-yl） fumarate （9） and dimethyl acetylenedi-carboxylate followed by reaction with some amines in refluxing ethanol. The identification of the compounds were based on spectroscopic analysis such as 1R （infrared）, UV （ultraviolet）, ^1H-NMR （nuclear magnetic resonance） and the microanalysis of the elements （CHN （microanalysis）） data.
基金This work was supported by the NNSFC (No. 29832030)
文摘N-(5-phenylseleno)pentyl succinimide 1, C15H19NO2Se (Mr = 324.27), was prepared by treating Br(CH2)5SePh with potassium succinimide. Its crystal structure has been determined by X-ray single-crystal diffraction. The crystal of 1 belongs to monoclinic system, space group P21/c with the crystal cell parameters: a = 18.018(6), b = 5.980(2), c = 14.682(5) ? = 109.977(6)? V = 1486.7(9) 3, Z = 4, Dc = 1.449 g/cm3, (MoK? = 2.523 mm-1, F(000) = 664,the final R = 0.0302 and wR = 0.0666 for 2623 independent observed reflections with I > 2(I). Structure analyses revealed that there exist strong nonclassical hydrogen bonds (CH…O).
文摘A novel strategy for site-selective benzylic C–H oxidation has been developed through mediated electrolysis.A bulky maleimide N-oxyl radical(MINO)generated by proton-coupled electrochemical oxidation of N-hydroxymaleimide(NHMI),serves as a hydrogen atom-transfer mediator.Good-to-excellent site selectivity was observed among different substrates,providing a practical approach for site-selective benzylic C–H oxidation.Additionally,the hydrogen-atom transfer mechanism for C–H electrochemical oxidation allows the oxidation to proceed at much lower anode potentials relative to direct electrolysis and with minimal reliance on the substrate's electronic properties.
文摘Aim To synthesize the tripepide Weinreb amide Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) as a useful precursor of aspartyl peptide aldehyde derivatives; Methods DCC, IBCF method was used for preparation of Weinreb amide; N hydroxysuccinimide activated ester was used in peptide synthesis; and Boc as N protecting group of amino acid. Results Boc Asp(OBzl) N(OMe)Me (3), Boc β Ala Asp(OBzl) N(OMe)Me (5), and Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) were synthesized successfully. Conclusion An useful precursor of tripeptide aspartyl aldehydes was synthesized.
基金Supported by China Petroleum & Chemical Corporation(No.200049).
文摘Terephthalic acid(PTA) is practically one of the main materials of polyester. Its corresponding solid-liquid equilibrium data will provide essential support for industry design and further theoretical studies. In this work,solid-liquid equilibriums of terephthalic acid in four solvents, N,N-dimethylformamide, N,N-dimethylacetamide,dimethylsulphoxide and N-methyl-2-ketopyrrolidene, were determined in the temperature range from 293.15 K to 364.6 K by dynamic method. All these data were regressed by λh model, Wilson model and NRTL model, average absolute relative deviations of which are 1.25%, 15.02% and 7.22% respectively. It indicates that λh model is mostsuitable for description of the solid-liquid equilibrium containing PTA.
