中国化学快报

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A New Method for the Cleavage of Carbohydrate Benzylidene Acetal by Ceric (IV) Ammonium Nitrate in CH₃CN-H₂O (10:1)

Shou Fu LU, Qin Qin OUYANG, Zhong Wu GUO, Biao YU, Yong Zheng HUI

中国化学快报. 1997, 8(10): 841-842.

摘要 ( )

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A new method for the cleavage of carbohydrate benzylidene acetal has been developed using Ceric (Ⅳ) ammonium nitrate (CAN) [(NH₄)₂Ce(NO₃)₆] in CH₃CN-H₂O (10/1,v/v).

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An Efficient One-step Methyl Esterification of Carboxylic Acid and Deacetylation of Alcohol under BF₃·OEt₂-MeOH

Shou Fu LU, Qin Qin OUYANG, Zhong Wu GUO, Biao YU, Yong Zheng HUI

中国化学快报. 1997, 8(10): 843-844.

摘要 ( )

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An efficient one-step methyl esterification of carboxylic acid and deacetylation of alcohol under BF₃·OEt₂-MeOH was developed.

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A New One-Pot Synthesis of Macroheterocycles Using Mannich Reaction

Min Min YANG, Jin Qi ZHANG, Zhen SHEN

中国化学快报. 1997, 8(10): 845-846.

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Three N,N'-heterylmethyl derivates of diaza-18-crown-6(I) are readily prepared by the reaction of (I) with paraformaldehyde and heterocyclic compounds in dry benzene.

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Preliminary Studies on Acylation of 10β-OH and 7α-OH in 7-Epi-10-deacetylpaclitaxel

Wei Shuo FANG, Qi Cheng FANG, Xiao Tian LIANG

中国化学快报. 1997, 8(10): 847-848.

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10β-OH can be acylated cleanly when 7α-OH is also free,and thus a facile access to semi-synthesis of 7-epi-paclitaxel was proposed.A 2's,3's-oxazoline paclitaxel analog was serendipitously synthesized.

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Synthesis of Dibenzo-sulfur-heterocycles through Reaction of Diphenyl-type Compounds with Elemental Sulfur over USY Zeolite

Bo Jun ZUO, Yu Dao MA, Yan TIAN, Qi Long WANG

中国化学快报. 1997, 8(10): 849-852.

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A series of dibenzo-sulfur-heterocycle compounds,such as phenothiazine,phenoxthine,thianthrene,thioxanthene and derivatives of dibenzothiophene were synthesized with satisfactory yields through reaction of the corresponding diphenyl-type compounds with elemental sulfur over a USY zeolite catalyst.

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The Synthesis of New Sulfur-containing Chiral Macrocyclic Ligand

Xiao Ling ZHANG, Jing Song YOU, Xing Shu LI, Ru Gang XIE

中国化学快报. 1997, 8(10): 853-854.

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Five new chiral sulfur-containing macrocyclic ligands which can be used in chiral recognition to guests have been synthesized and characterized.

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Stereoselective Synthesis of 2-Chloro-4-Substituted-phenyl-5,5-Dimethyl-1,3,2-Dioxaphosphorinan-2-(Thi)ones

Rui Lian SHAO, Guang Fu YANG, Wei Shi MIAO, Min Hua YANG

中国化学快报. 1997, 8(10): 855-858.

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The stereoselective synthesis of 2-chloro-4-substituted-phenyl-5,5-dimethyl-1,3,2-dioxaphosphorinan-2-(thi) ones is described.Only single trans-isomers were obtained when 1-substituted-phenyl-2,2-dimethyl-1,3-propanediols (1) reacted with POCl₃.But the stereoselectivity of cyclization reaction between (1) and PSCl₃ depended greatly upon the reaction condition.The configurational assignments and the ratio of cis-/trans-diastereoisomers of the products were performed on the basis of ¹HNMR,³¹PNMR and IR spectra and confirmed by X-ray diffraction analyses.

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Synthesis of 11-demethyl and 6, 6,11-demethyl Calanolide A

Chun Mei ZHOU, Lin WANG, Zhi Zhong ZHAO

中国化学快报. 1997, 8(10): 859-860.

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Synthesis of 11-demethyl and 6,6,11-demethyl calanolides A (6-9) have been carried out by a four-step reaction sequence using a simple approach in order to investigate the structural requirements necessary for antiviral activity.

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Studies on the Synthesis of Preverecynarmin

Ya Cheng XING, Wen CEN, Yu Lin LI

中国化学快报. 1997, 8(10): 861-862.

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A precursor 9 of preverecynarmin was prepared by starting from isoprene and geraniol.The key steps in synthesis are the addition of sulfurstabilized carbanion to aldehyde and alkylation with allylic chloride.

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Synthesis of 7-Epi-howiinol A

Shao Yi SUN, De Quan YU

中国化学快报. 1997, 8(10): 863-864.

摘要 ( )

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7-Epi-howiinol A,an antitumor lactone,has been synthesized in nine steps starting from α-D-glucoheptonic γ-lactone with an overall yield of 8.5%.

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Total Synthesis of α-Chamigrene and β-Chamigrene

Jin Jun WANG, Lian Hai XUE, Jun QIU, Guang Quan WANG

中国化学快报. 1997, 8(10): 865-868.

摘要 ( )

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α-Chamigrene (12) and β-chamigrene (15) were synthesized via a useful synthon in the synthesis of chamigrene-type sesquiterpenes,i.e.,1-methoxycarbonyl 5,5,9-trimethyl spiro-[5,5] undeca-1,8-dien-3-one(6),which had been prepared from a retro-aldol rearrangement product of proto-[2+2] photocycloadducts obtained by means of photoaddition reaction of terpinolene with methyl 2,4-dioxopentanoate.

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The Mechanism of the Initial Dark Oxidation of Ethers and the Ether-Oxygen Contact Charge Transfer Complex

Jun Min ZHU, Wei Xiao CAO, Xin De FENG

中国化学快报. 1997, 8(10): 869-872.

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The contact charge transfer (CCT) absorption spectra of isopropyl ether,phenyl isopropyl ether and benzyl isopropyl ether with oxygen were measured.The mechanism of the initial dark oxidation of different ethers via ether-O₂ CCT was proposed.

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A New Glucoside from Ceratostigma willmottianum

Jian Min YUE, Yu ZHAO, Jun XU, Zhong Wen LIN, Han Dong SUN

中国化学快报. 1997, 8(10): 873-874.

摘要 ( )

可视化

Ceratoside A (1),a new compound was isolated from the butanol-soluble fraction of Ceratostigma willmottianum,Its structure was determined by the utilization of 2D-NMR techniques.

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HPLC of Amino Acids and Oligopeptides by Pre-Column Fluorescence Derivatization with 9-Acridine Formyl Chloride

Jin Mao YOU, Xin Jun FAN, Qing Yu OU

中国化学快报. 1997, 8(10): 875-878.

摘要 ( )

可视化

A highly sensitive HPLC method for the detection of amino acids and oligopeptides with 9-acridine formyl chloride by.pre-column fluorescence derivatization has been developed.Glycine.glycylglycine,histidine,triglycine and glutathione were separated on a reversed-phase C₁₈ column with methanol-water-triethylamine eluent,derivatization and chromatographic conditions were optimized.The five derivatives were eluted in 28 min with a good reproducibility.Linear range of the calibration graph was 0.08-260 nmol/ml^-1.The relative standard deviations(n=6) are < 5%.Detection limits (signal-to-noise ratio=3) for the five derivatives are 20-40 fmol.

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Formation of the [M+NH₄]⁺ Ious of Some Mouo-and Di-saccharides in Fast Atom Bombardment Mass Spectrometry

Jian Jun ZHAI, Fan Zhi ZHAO, Cheng Gang HUANG, Yao Zu CHEN, Jin Shan GUO

中国化学快报. 1997, 8(10): 879-882.

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可视化

In positive-ion fast atom bombardment (FAB) mass spectrometry,when mono-and di-saccharides are mixed with an appropriate amount of NH₄Cl,a highly abundant peak [M+NH₄]⁺ appears in FAB mass spectra.From the adduct ion [M+NH₄]⁺,the molecular weights of mono-and di-saccharides can be determined definitively.

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Spectrometric Study of α-Phenylcinnamic Acids

Xin HE, Li Yuan MOU, Zi Yun LIN, Li Ya ZHU, Xiao Tian LIANG

中国化学快报. 1997, 8(10): 883-884.

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Fourteen substituted α-phenylcinnamic acids were prepared by the classical Perkin condensation.A plausible way of cleavage was involved in the formation of the specific fragment peaks in the MS of the α-phenylcinnamic acids.The characteristic chemical shift of the olefinic proton in ¹HNMR is also discussed.

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Conformational Analysis of γ-Butyrolactones by Nuclear Magnetic Resonance Spectroscopy

Fu An KANG, Cheng Lie YIN

中国化学快报. 1997, 8(10): 885-888.

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可视化

A series of trans-4,5-disubstituted-γ-butyrolactones are found to assume two different envelope conformations by means of nuclear magnetic resonance spectroscopy.

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The QSAR Research of Pyrrolobenzothiazepinones and Pyrrolobenzo-xazepinones-Novel and Specific Non-Nucleoside HIV-1 Reverse Transcriptase Inhibitors

Jun Mei WANG, Ting Jun HOU, You Yong Li, Xiao Jie XU

中国化学快报. 1997, 8(10): 889-892.

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The quantitative structural parameters and activity relationship of pyrrolobenzo-thiazepin-ones and pyrrolobenzoxazepinones' inhibitory activities on HTV-1 reverse transcriptase (RT) was studied.A good relationship has been built.

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Study on 3D Quantitative Structure-Activity Relationships of Taxoid

Qi Qing ZHU, Zong Ru GUO, Niu HUANG, Min Min WANG, Feng Ming CHU

中国化学快报. 1997, 8(10): 893-896.

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A series of 94 taxol analogues exhibiting antitumor activity were investigated using comparative molecular field analysis (CoMFA) method.The most optimal CoMFA from 80 compounds selected randomly yielded a two-components model,with significant cross-validation r²_cv of 0.640 and conventional r² of 0.868.The robustness of the CoMFA model was further validated by prediction of 14 test set compounds.The CoMFA model explained present SAR and particularly the importance of the hydroxyl group at C-2' position and the stereochemistry at C-2' and C-3' positions.

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Physical Diffusion and Electron-transfer Dynamics of Electroactive Solutes in Polymer Electrolytes Ⅱ. Effect of the Ionic Size of Supporting Electrolytes

Li Ming DING, Hua Fang ZHOU, Zhong SHI, Shao Jun DONG

中国化学快报. 1997, 8(10): 897-900.

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The diffusion coefficients(D_app) and the heterogeneous electron-transfer rate constants(k_s) for ferrocene in MPEG/salt electrolytes were determined by using steady-state voltammetry.The temperature dependence of the two parameters obeys the Arrhenius equation.The effect of the ionic size of six supporting electrolytes on diffusion and electron transfer dynamics of ferrocene was discussed.

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Physical Diffusion and Electron-transfer Dynamics of Electroactive Solutes in Polymer Electrolytes Ⅲ. Effect of the Polymer Solvents

Li Ming DING, Zhong SHI, Hua Fang ZHOU, Shao Jun DONG

中国化学快报. 1997, 8(10): 901-904.

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The diffusion coefficients(D_app) and the heterogeneous electron transfer rate constants(k_s) for ferrocene in several polymer solvents were determined by using steady-state voltammetry.The temperature dependence of the two parameters indicates Arrhenius behavior.The polymer solvent effects on diffusion and electron transfer dynamics of ferrocene were discussed.

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Axial Coordination Effects of Pyridine on the Electrochemistry of (TPP)Co in 1,2-Dichloroethane Solution

Chuan Wei YAN, Xiang Qin LIN, Hai Chao LIN, Chu Nan CAO

中国化学快报. 1997, 8(10): 905-908.

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The electrochemistry of (TPP)Co in the presence of pyridine was investigated in dichloroethane solution by cyclic voltammetry.With the addition of pyridine to the solution,the reduction peaks of the axial complex compounds, (TPP)Co(Ⅲ)(Py) and (TPP)Co(Ⅲ)(Py)₂ were observed.It was found that the reduction peak of Co(Ⅱ)/Co(Ⅰ) shifted to about-1.20V (SCE) with the increase of added pyridine.The new reduction peak may be attributed to the direct reduction of the axially complex (TPP)Co(Ⅱ)(Py).

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Electrochemical and Spectroelectrochemical studies of Mixed-Valence Heteropolyanion VMo₁₂O₄₀^n- (n=4,5,6) in Aprotic Media

Shu Yan ZHANG, Hao Ran SUN, Ji Qing XU, Tong Shun SHi

中国化学快报. 1997, 8(10): 909-912.

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The mixed-valence heteropolyanion VMo₁₂O₄₀^n- (where n=4,5,6) in aprotic media was investigated by cyclic voltammetry and in-situ FTIR and UV-visible-near-IR spectroelectrochemical methods.The results indicate that the heteropolyanion VMo₁₂O₄₀^3- undergoes three reversible one electron transfer reductions and the mixed-valence heteropolyanion VMo₁₂O₄₀^n- (where n=4,5,6) was formed after electroreduction.The spectra of the aforementioned mixed-valence compounds were characterized by in-situ spectroelectrochemical methods.

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Fabrication of Multilayer Film Electrode Containing 12-Tungstosilicate Anions and Its Electrocatalytic Reduction for Dioxygen

Chang Qing SUN, Ji Dong ZHANG

中国化学快报. 1997, 8(10): 913-916.

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A novel multilayer film electrode containing 12-tungstosilicate anions was achieved on the surface of gold electrode by alternating deposition of 12-tungstosilicate anions with 60% quaternized poly(4-vinylpyridine) based on electrostatic interaction.The chemically-modified electrode exhibits a high catalytic activity towards the electroreduction of molecular oxygen.

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Synthesis and Electrical Conductivity of MDA [Ni(dmit)₂]₂

Shu Qing SUN, Xiao Yin XU, Qi Chun ZHANG, Pei Ji WU, Dao Ben ZHU

中国化学快报. 1997, 8(10): 917-918.

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Single crystals of MDA [Ni(dmit)₂]₂ were synthesized by using electrooxidation method.Electrical conductivity measurements exhibit a semiconducting feature with high conductivity at room temperature.

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Theoretical Investigation of Small Lathanum Carbide Clusters

Zhi Jian WU, Qing Bo MENG, Si Yuan ZHANG

中国化学快报. 1997, 8(10): 919-922.

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LaC₂⁺,LaC₂²⁺,LaC₃ and LaC₃^- clusters have been studied using B3LYP density functional method.Four isomers with C_2V,C_S,C_∞V and D_∞h symmetry were presented for LaC₂⁺ and LaC₂²⁺.Meanwhile,two spin states,namely,singlet and triplet for LaC₂⁺,doublet and quartet for LaC₂²⁺,were considered.The results indicated that ring isomers with C_2V and C_S symmetry are the most stable for LaC₂⁺ at both spin states and for LaC₂²⁺ at quartet state.Whereas for LaC₂²⁺ at doublet state,linear isomer with C_∞V symmetry is energetically favored.For LaC₃ and LaC₃^- clusters,three isomers have been presented for each cluster,that is,two ring isomers with C_2V symmetry (in one of them,La forms two single bonds with two carbons,and in another,La forms a double bond with carbon),and one linear isomer with C_∞V symmetry.The results revealed that the ring isomer in which La forms two single bonds with carbons is the lowest in energy.

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The Study of Cation Distributions in the Dehydrated KFI-Type Zeolites

Shui Ping ZHU, Qing Hua JIN, Zhen Ya GUO, Bao Hui LI, Da Tong DING

中国化学快报. 1997, 8(10): 923-926.

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Based on four constant parameters (the site energy differences E_M2-E_M1=25.50 kJ/mol,E_M3-E_M1=-10.73 kJ/mol and the potential energies of interactions between the cation pairs occupying adjacent sites W₁₂=45.60 kJ/mol,W₁₄=0.56 kJ/mol) and a temperature-dependent parameter E_M4-E_M1=2.68 (T/7323)^2.5 kJ/mol,the equilibrium distributions of the exchangeable cations,K^+,s,over those four available cation sites in K_22.4Al_22.4Si_73.6O₁₉₂ are studied by the simulated annealing method.

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Synthesis of A Novel Aluminosilicate with Bimodal Mesopore Distribution

Zhong Yong YUAN, Jing Zhong WANG, He Xuan LI, Zhi Xiang CHANG

中国化学快报. 1997, 8(10): 927-930.

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A novel aluminosilicate with well-defined bimodal mesopore distribution has been synthesized directly,in which one mesopore is distributed at around 3.8nm and the other at 2.6nm.

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A Novel Method of the Modification of Ultrastable Y Zeolites With Citric Acid in Unbuffered System

Rong Gang DING, Ling QIAN, Lin Hua SONG, Zi Feng YAN, Huai Ping WANG

中国化学快报. 1997, 8(10): 931-934.

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可视化

The feasibility of preparing high Si/Al ratio samples by treating USY zeolites with citric acid solution in unbuffered system was extensively investigated.The effect of treating conditions was explored.The results show that Si/Al ratios,crystallinities,contents of crystalline silicon and thermal stabilities of the samples are greatly increased after moderate modification.It means that it might be an effective method for the moderate modification of USY samples.

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1997年, 第8卷, 第10期　刊出日期：1997-10-20

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1997年, 第8卷, 第10期 刊出日期：1997-10-20

1997年, 第8卷, 第10期　刊出日期：1997-10-20