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191.
The reaction of O-methyl tetramethyldiamidophosphite with 3-bromopropanol or 3-bromo-2-butanol occurs with the liberation of dimethylamine and results in mixed phosphites. The reaction of O-methyl tetramethyldiamidophosphite with 3-thiocyano-2-butanol proceeds with the participation of the sulfur atom of the thiocyano group and formation ofS-(3-hydroxybutyl) tetramethyldiamidothiophosphate.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 167–169, January, 1994. 相似文献
192.
193.
利用可积系统的思想,借助三维Minkowski空间L3的矩阵模型,研究了L3中具有调和逆平均曲率的类空曲面和洛伦兹调和逆平均曲率类时曲面的可积性及其形变. 相似文献
194.
195.
V. A. Potemkin M. A. Grishina E. V. Bartashevich 《Journal of Structural Chemistry》2007,48(1):155-160
The BiS algorithm is suggested for modeling the drug molecule orientation within a receptor cavity. It is based on the assumption of complementarity of the field created by biologically active compounds and the field of the responsive receptor. The comparison of predicted orientations of various biologically active compounds on the relevant receptors with the data of X-ray structural studies (Protein Data Bank) reveals that the results obtained with this approach surpasses those reported in the literature. The suggested technique made it possible to elucidate the details of the action mechanism of DNA antimetabolites, dihydrofolate reductase inhibitors. The dependence of the activity on the structural parameters of “ligand-receptor” complexes is determined. 相似文献
196.
R. Souzy B. Ameduri B. Boutevin 《Journal of polymer science. Part A, Polymer chemistry》2004,42(20):5077-5097
The radical co‐ and terpolymerization of 4‐[(α,β,β‐trifluorovinyl)oxy]bromo benzene (TFVOBB) with 1,1‐difluoroethylene (or vinylidene fluoride, VDF, or VF2), hexafluoropropene (HFP), perfluoromethyl vinyl ether (PMVE), and chlorotrifluroroethylene (CTFE) is presented. Although TFVOBB could be thermocyclodimerized, it could not homopolymerize under radical initiation. TFVOBB could be copolymerized in solution under a radical initiator with VDF or CTFE comonomers, while its copolymerization with HFP or PMVE were unsuccessful. The terpolymerization of TFVOBB with VDF and HFP, or VDF and PMVE, or VDF and CTFE also led to original fluorinated terpolymers bearing bromoaromatic side‐groups. The conditions of co‐ and terpolymerization were optimized in terms of the nature of the radical initiators, and of the nature of solvents (fluorinated or nonhalogenated). Various monomer concentrations in the co‐ and terpolymers were assessed by 19F and 1H‐NMR spectroscopy. The thermal and physico chemical properties were also studied. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5077–5097, 2004 相似文献
197.
A. S. Peregudov L. N. Usatova E. I. Smyslova E. I. Fedin D. N. Kravtsov 《Russian Chemical Bulletin》1995,44(8):1513-1519
It has been shown by the19F NMR method that the relative polarities of nitrogenelement bonds in 2-(4-fluorophenyl)benzimidazole and its PhHg and PPh3Au derivatives increase in the order N-H19F NMR. It has been found that these reactions occur by a bimolecular associative mechanism and that the N-H bond is substantially less reactive than the N-Hg and N-Au bonds, which have identical reactivities within the limits of sensitivity of the method used.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1574–1580, August, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No. 93-03-5528). 相似文献
198.
N—烃氧丙酰基四氢噻唑—2—硫酮的合成 总被引:1,自引:0,他引:1
在三聚氯氰存在下由烃氧丙酸与四氢噻唑-2-硫酮反应得到N-烃氧丙酰四氢噻哇-2-硫酮(2a-i),由2a,c-h与格氏试剂反应得到烃氧乙基苯基酮(3a,c-h).产物2a-i未见报道. 相似文献
199.
A general class of Fuller modified maximum likelihood estimators are considered. It is shown that this class possesses finite moments. Asymptotic bias and asymptotic mean squared error are derived using small-σ expansions. A simulation study is carried out to compare different estimators in this class with standard estimators. 相似文献
200.
Michael-Addition Reaction of Malononitrile with a,β-Unsaturated Cycloketones Catalyzed by KF/Al_2O_3
The utility of fluoride salts as potential base in a va-riety of synthetic reactions has been recognized in re-cent years.1 However, low solubility of fluoride salts in ordinary solvents hampers their wide applications in organic synthesis. On the other hand, there has been increasing use of inorganic solid supports as catalysts for many years2 resulting in higher selectivity, milder reaction conditions and easier work-up. Especially po-tassium fluoride-coated alumina (KF-alumina) has been a … 相似文献