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排序方式: 共有1603条查询结果,搜索用时 15 毫秒
1.
Jong Chan Lee Jin Young Park So Young Yoon Yong Hun Bae Seung Jun Lee 《Tetrahedron letters》2004,45(1):191-193
A novel and direct method for the synthesis of α-halocarbonyl compounds using sequential treatment of carbonyl compounds with [hydroxy(tosyloxy)iodo]benzene followed by magnesium halides under solvent-free microwave irradiation conditions is described. 相似文献
2.
We show that using ionic liquids as reagents in conjunction with microwave heating it is possible to prepare primary alkyl halides from the corresponding alcohols rapidly. Using ionic liquids as solvents in conjunction with microwave heating it is possible to prepare aryl nitriles from the corresponding aryl bromides or iodides. The scope and limitations of using microwave-promotion as a tool in these reactions is discussed. 相似文献
3.
A variety of aryl nitriles were prepared in excellent yields from the palladium acetate catalyzed coupling of aryl halides with Zn(CN)2 using polymer-supported triphenyl phosphine as the ligand and dimethylformamide as solvent under microwave irradiation conditions. 相似文献
4.
In the present paper, a new two-parameter inverted equation of state (EOS) is developed which is found to be working very
well in the high-pressure region. To check its success and validity, this EOS has been applied in a number of solids. The
computed volume compression is found to be in very good agreement with the experimental data in the whole range of pressure
in all the solids. The minimum and the maximum pressure range used in the present study is 0–320 kbar and 0–3000 kbar, respectively. 相似文献
5.
Adriana Tudose 《Tetrahedron letters》2006,47(48):8529-8533
Simple catalysts formed in situ from palladium acetate and a variety of imidazolium and imidazolinium carboxylates and dithiocarboxylates have been screened in the coupling of aryl halides with trans-2-phenylvinylboronic acid. Imidazol(in)ium carboxylates show an excellent activity, which compares to that displayed by the parent imidazol(in)ium chlorides, whereas imidazol(in)ium dithiocarboxylates are poorly efficient. Interestingly, the base employed exerts a profound influence on the trans/cis stereochemistry of the coupling product. 相似文献
6.
Bobonich F. M. Yaroshenko N. A. Solomakha V. N. Strelko V. V. Il'in V. G. 《Theoretical and Experimental Chemistry》2004,40(4):254-259
Under the conditions studied for the synthesis of mesophase materials with alkylpyridinium halides an increase in the density of packing of these molecules in the encapsulated micelles was observed with an increase in the length of the alkyl radicals. The difference in the density of packing of these surface active reagents (SAR) depended to a considerable extent on the perfection of the hexagonal structure and the characteristic absorption properties of the mesophase materials of MCM-41 type. 相似文献
7.
Georgiy B. Shul’pin Camilla C. Golfeto Lidia S. Shul’pina 《Tetrahedron letters》2005,46(27):4563-4567
The H2O2-FeCl3-bipy system in acetonitrile efficiently oxidises alkanes predominantly to alkyl hydroperoxides. Turnover numbers attain 400 after 1 h at 60 °C. It has been assumed that bipy facilitates proton abstraction from a H2O2 molecule coordinated to the iron ion (these reactions are stages in the catalytic cycle generating hydroxyl radicals from the hydrogen peroxide). Hydroxyl radicals then attack alkane molecules finally yielding the alkyl hydroperoxide. 相似文献
8.
9.
Summary A fumed silica surface was systematically modified by the grafting of n-alkyl chains with increasing carbon numbers. The samples
were characterized by the dispersive component of the surface energy, their specific interaction potential and enthalpies
of adsorption of polar, in particular, alcohol probes. It is shown that the variation of the surface properties and adsorption
capacities depend on the chain length of the graft. For instance, minimum values are recorded when the surface coverage by
methylene groups corresponds either to one or two CH2 surface layers. This behaviour is related to the mobility of the grafted alkyl chains, mobility which was examined by solid
state NMR. 相似文献
10.
Lyudmila V. Chernykh Jitka Eysseltova Mikhail Y. Skripkin 《Monatshefte für Chemie / Chemical Monthly》2003,134(5):751-761
Summary. Solubility isotherms in the CuBr2−MBr−H2O (M
+ = Li+, Na+, Cs+) systems at 298.15 K were measured. The results together with other available literature data for copper chloride and bromide
systems were treated by hydration analysis, and comparative discussion of ionic processes taking place in the respective saturated
solutions was performed.
Corresponding author. E-mail: jitka@prfdec.natur.cuni.cz
Received August 6, 2002; accepted (revised) November 29, 2002
Published online April 3, 2003 相似文献