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31.
Intramolecular alkene-carbonyl coupling reaction of N-benzyl-N-(o-alkenylaryl)carbamate derivative derived from o-aminostyrene, o-(aminomethyl)styrene and o-aminoallylbenzene smoothly proceeded by treating with zirconocene-butene complex to give the corresponding lactam derivative.  相似文献   
32.
Sphingomyelinase (SMPLC) from Bacillus cereus was modified with a polyethylene glycol (PEG) derivative, methoxypolyethylene glycol-succinimidyl succinate (ss-PEG). The molecular weight of the ss-PEG-modified SMPLC was calculated to be approx. 150 kDa by gel-filtration whereas that of the native enzyme, was 25 kDa. By this modification, the enzyme increased its thermostability and retained its hydrolytic activity toward 2-(N-hexadecanoylamino)-4-nitrophenylphosphocholine (HNP) and sphingomyelin (SM) in the mixed micelles with the surfactants such as Triton X-100 and sodium deoxycholate (SDC). However, the activity toward liposomal SM was significantly decreased, and all the enzyme activities toward bovine erythrocytes, including membraneous SM-hydrolyzing and hemolytic activities as well as the enzyme adsorption onto the erythrocyte membranes, were completely lost.  相似文献   
33.
Polystyrene-bound 4-(1-pyrrolidino)pyridine moieties were prepared by the reaction of chloromethylated polystyrene resins with pyrrolidinopyridine derivatives containing hydroxyl groups. The supported amines were effective catalysts for acylations of tert-alcohols or enols, acylrearrangements, and diester synthesis from epoxides and anhydrides. Some of the low ring-substituted (8–15%) catalysts exhibited high activity comparable to that of 4-(N,N-dimethylamino)pyridine, though the activity was a little lower than that of 4-(1-pyrrolidino)pyridine. The recovered catalysts can be re-used, except for acyl rearrangements, without significant decrease in activity.  相似文献   
34.
Synthesis of (1R,2S,5S,6R,8S)-3-azabicyclo[3.3.0]octane-2,6,8-tricarboxylic acid (2) from trans-4-hydroxy-L-proline (5) was attempted. A Diels-Alder reaction of 3,4-dehydroproline derivative 9 and cyclopentadiene afforded a single stereoisomer 11. The Diels-Alder adduct was smoothly converted to the hydrochloride of 2 (24) via RuO(4) oxidation. Although some racemization of the material or product was observed during the synthetic processes, the amino acid 24 proved to be optically pure.  相似文献   
35.
Mono- and multilayers of amphiphilic [Ru(phen)(2)(dcC12bpy)](2+) (phen = 1,10-phenanthroline, dcC12bpy = 4,4'-caboxyl-2,2'-bipyridyl didodecyl ester) hybridized with a clay mineral have been prepared by a modified Langmuir-Blodgett method, and their structures and properties have been investigated. Formation of a hybrid monolayer of the Ru(II) complex cations and the clay platelets at an air-clay suspension interface was confirmed by surface pressure-molecular area (pi-A) isotherm measurement and atomic force microscopic (AFM) observation. Multilayers were fabricated by depositing the hybrid monolayers onto glass substrates. The absorbance at 492 nm due to the Ru(II) complex cation in the multilayer increased linearly with the increase in the layer number, indicating layer-by-layer deposition of the hybrid monolayers. Because no increase in the second-harmonic generation (SHG) signal from the multilayers against the layer number was observed, the orientation of the Ru(II) complex cations in the layer would be disturbed. The hydrophilic surface of the transferred hybrid monolayer can be converted to a hydrophobic surface by dipping it in an aqueous solution of octadecylammonium chloride (ODAH(+)Cl(-)). The multilayers modified with ODAH(+) showed a quadratic relation between the SHG intensity and the layer number. This means that the Ru(II) complex cations in the multilayer are successfully oriented in a noncentrosymmetric way by the conversion of the surface property. Both a racemic mixture and an enantiomer of the Ru(II) complex cations were employed to examine the chiral effect on the film properties. The chiral contribution to the SHG signal was enhanced in the multilayer modified with ODAH(+).  相似文献   
36.
[structure: see text] Novel hydrogen-bonded charge-transfer salts of TCNQ with mono- and diprotonated 4,4'-biimidazolium were synthesized in order to demonstrate the high potential of the 4,4'-biimidazole system in a molecular conductor from the viewpoint of crystal engineering and electronic modulation. Crystal structure analyses of neutral 4,4'-biimidazole and TCNQ salts revealed the formation of two types of hydrogen-bonding modes of the 4,4'-biimidazole moiety depending on the protonated states. Neutral 4,4'-biimidazole possessed a linear chain mode of hydrogen-bonding to construct two-dimensional network. In the TCNQ salt of monoprotonated 4,4'-biimidazolium, the 4,4'-biimidazole moiety formed a dimer by a complementary mode of hydrogen-bonding. In contrast, the salt of diprotonated 4,4'-biimidazolium showed a double linear chain mode of hydrogen-bonding to construct a three-dimensional network. The formation of two types of hydrogen-bonding modes made the difference in the stacking patterns of TCNQ columns and in their transport properties. The TCNQ salt of diprotonated 4,4'-biimidazolium exhibited high electrical conductivity (sigma(rt) = 1.1 x 10(-1) S cm(-1)).  相似文献   
37.
Nanocomposites consisting of conducting polyaniline and clay minerals were successfully synthesized from mechanochemically intercalated anilinium fluoride; the nanocomposites prepared by the mechanochemical intercalation method contained much more polyaniline in the clay layers than those prepared by a conventional solution method.  相似文献   
38.
Direct fluorination of 1,3-dioxolan-2-one with elemental fluorine was successfully carried out to provide 4-fluoro-1,3-dioxolan-2-one, which was expected as an additive for lithium ion secondary battery. 4-Fluoro-1,3-dioxolan-2-one was also further fluorinated with elemental fluorine to give three isomers of difluoro derivatives by the same methodology. Another topic is the preparation of trifluoromethanesulfonyl fluoride, an intermediate of lithium battery electrolyte, by the reaction of methanesulfonyl fluoride with elemental fluorine. The use of perfluoro-2-methylpentane as a solvent gave satisfactory selectivity of trifluoromethanesulfonyl fluoride.  相似文献   
39.
A catalyst for the polymerization of epoxides consisting of trialkylaluminums, cyclic ethers, and cyclic imides has been investigated. Various catalyst components were examined to reveal that the combination of triisobutylaluminum, dioxane, and succinimide gives the most active catalyst. The catalytic activity is greatly enhanced with aging in which the change in color from pale yellow to dark red takes place. The polymerization data show that the dioxane provides a pathway for the catalyst components to form an active species. The dioxane-containing catalyst is likely to be different in structure from that of the dioxane-free catalyst. It was shown that the catalyst solution is electrically conductive. A parallel correlation seems to exist between the electrical conductivity and the catalytic activity, suggesting that the catalytic species may be of an ionic character.  相似文献   
40.
A structure-activity relationship (SAR) study on 5-substituted oxazolidinones as an antibacterial agent is described. The oxazolidinones, of which 5-acetylaminomethyl moiety was converted into other functions, were prepared and evaluated for antibacterial activity. Elongation of the methylene chain (8) and conversion of the acetamido moiety into guanidino moiety (12) decreased the antibacterial activity. The replacement of carbonyl oxygen (=O) by thiocarbonyl sulfur (=S) enhanced in vitro antibacterial activity. Especially, compound 16, which had the 5-thiourea group, showed 4-8 stronger in vitro activity than linezolid. Our SAR study revealed that the antibacterial activity was greatly affected by the conversion of 5-substituent.  相似文献   
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