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γ-Hydroxy-α,β-acetylenic esters:asymmetric syntheses and applications

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Science China chemistry 2010年第1期53卷 21-35页

作者： GAO Ge1 & PU Lin2.1department of chemistry,{2. university,chengdu 610064,China 2.0} of chemistry,university of Virginia,Charlottesville,Virginia 2.904-4319,USA department of chemistry Sichuan University Chengdu China department of chemistry University of Virginia Charlottesville USA

γ-Hydroxy-α,β-acetylenic esters are versatile synthetic precursors to many organic *** paper reviews the synthesis of chiral γ-hydroxy-α,β-acetylenic esters by asymmetric reduction of γ-oxo-α,β-acetylenic esters,enantioselective addition to aldehydes in the presence of chiral catalysts,and diastereoselective addition to chiral *** preparation of racemic γ-hydroxy-α,β-acetylenic esters is also *** are provided for the application of γ-hydroxy-α,β-acetylenic esters in organic synthesis.

关键词： γ-hydroxy-α β-acetylenic ester asymmetric enantioselective diastereoselective

Theoretical study on the hydrolysis mechanism of N,N-dimethyl-N′-(2.,3′-dideoxy-3′-thiacytidine)formamidine

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Science China chemistry 2008年第10期51卷 911-917页

作者： ZHANG Chang1 & XUE Ying2. 1 College of chemistry and Environment Protection Engineering, Southwest university for Nationalities, {2. 610041, China 2.College of chemistry, sichuan university, chengdu 610064, China College of chemistry and Environment Protection Engineering Southwest University for Nationalities Chengdu China College of chemistry Sichuan University Chengdu China

The hydrolysis mechanisms of N,N-dimethyl-N′-(2.,3′-dideoxy-3′-thiacytidine)formamidine (FA-3TC) in the gas phase and in aqueous solution were studied by use of the density functional theory B3LYP/6-31+G(d, p) method. Two possible reaction pathways in the title reaction were considered. In one pathway water attacks the C=N double bond first (path A) while in the other water attacks the C—N single bond first (path B). The calculated results indicate that the first step in both pathways is the rate-limiting process and path A is more favorable than path B in the gas phase. The effect of solvent water on the title reaction was assessed at the B3LYP/6-31+G(d, p) level of theory based on the po-larizable continuum model (CPCM). In water the first mechanism (path A) is also favored.

关键词： N N-dimethyl-N′-(2. 3′-dideoxy-3′-thiacytidine)formamidine hydrolysis solvent effect B3LYP polarizable continuum model

Characteristic analysis for a polynomial-like iterative equation

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Chinese Science Bulletin 1998年第3期43卷 192-196页

作者： Janusz Matkowski 1 and ZHANG Weinian 2.1. department of Mathematics, Technical university, 43_300 Bielsko_Biala, Poland 2. department of Mathematics, sichuan Union university, chengdu 610064, China department of Mathematics Technical University Bielsko-Biala Poland department of Mathematics Sichuan Union University Chengdu China

In the light of Euler’s idea for differential equations,a polynomial_like n _order iterative equation is discussed through analyzing its characteristic polynomial. An unproved result is verified rigorously for the fi... 详细信息

关键词： iterative dynamics functional equation characteristic.

Cartesian closedness of categories of completely distributive lattices

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Chinese Science Bulletin 1998年第24期43卷 2059-2063页

作者： ZHANG Dexue 1 and YANG Zhongqiang 2.1. department of Mathematics, sichuan university,{2., China 2. department of Mathematics, Shaanxi Normal university, Xi’an 710062. China department of Mathematics Sichuan University Chengdu China department of Mathematics Shaanxi Normal University Xi’an China

The category of completely distributive lattices with Scott continuous functions is cartesian closed. Neither the category of completely distributive lattices with arbitrary union preserving mappings nor the category ... 详细信息

关键词： completely distributive lattice continuous lattice cartesian closedness.

Theoretical study of the potential energy surface and the highly excited rovibra-tional spectroscopy of H_2. molecule

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Chinese Science Bulletin 2001年第8期46卷 650-652页

作者： XIE Junkai & YAN Guosendepartment of chemistry, {2. Normal university, chengdu 610066, China department of chemistry, sichuan university, chengdu 610064, China department of chemistry Sichuan Normal University Chengdu China department of chemistry Sichuan University Chengdu China

This note reports the potential energy surface of H2. that has been refined by using SCF-CI approach and the high-resolution experimental data. The calculated splitting values of the local mode vibration states pair close to observed values. This vibration state calculation has shown that there are no obvious non-Born Oppenheimer effects occurring in the lower vibration states of the system.

关键词： potential energy surface local mode vibration state non- Born Oppenheimer effect.

Enantioselective Reduction of Prochiral Ketones Catalyed by Oxazaborolidine Derived from L-Cystine

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Chinese Chemical Letters 1997年第8期8卷 679-680页

作者： Xing Shu Li Xiao Ling Zhang Ru Gang Xie(department of chemistry, {2. Union university, chengdu, 610064)(department of chemistry, {2. Educational College, chengdu, 610041) department of chemistry Sichuan Union University Chengdu 610064 China department of chemistry Sichuan Educational College Chengdu 610041 China

Two new chiral oxazaborolidine derivated from L-cystine have been used to catalyze the enantioselective reduction of prochiral ketones and the secondary alcohols are obtained with good to excellent opitical yields.

关键词： Enantioselective Reduction of Prochiral Ketones Catalyed by Oxazaborolidine Derived from L-Cystine

APPLICATIONS OF THE THEORY OF CAMINA GROUPS

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Chinese Annals of Mathematics,Series B 1999年第1期20卷 39-50页

作者： REN YONGCAI(department of Mathematics,sichuan Union {2.,chengdu 610064,China) department of Mathematics Sichuan Union University Chengdu 610064 China

In this papert the author first gives a conjugacy-class version of Camina hypotheses andthen applys the Camina group theory to discussing two classes of finite groups.

关键词： Camina groups Applications Characters

Dioxygen Affinities and Catalytic Epoxidation Performanceof Transition-Metal Hydroxamates

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Chinese Chemical Letters 1999年第1期10卷 79-82页

作者： Hua YANG Sheng Ying QIN Xiao Xia LU(department of chemistry,{2., chengdu 610064) department of chemistry Sichuan University Chengdu 610064 China

The dioxygen affinities and catalytic epoxidation performance of transition-metal hydroxamates were investigated for the first time. The effects of substituents on these properties were also discussed in the paper.

关键词： transition-metal hydroxamates dioxygen affinities catalytic epoxidation

SYNTHESIS OF LIQUID CRYSTALS CONTAINING THE AZA-15-CROWN-5 UNIT

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Chinese Chemical Letters 1996年第3期7卷 213-216页

作者： Wei ZHAO Ming Gut XIE Qing JIANG(department of chemistry,{2., chengdu, 610064.) department of chemistry Sichuan University Chengdu 610064

Two new aryl esters with the aza-15-crown-5 structural unit were synthesized. Their structures have been elucidated with IR, (1)HNMR, MS and elementary analysis. The determinations of DSC and textures have shown that ... 详细信息

关键词： POLYMERS ETHERS