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991.
Manuel Alberto Flores‐Hidalgo Daniel Glossman‐Mitnik D. H. Galvan Diana Barraza‐Jimenez 《中国化学会会志》2013,60(8):1082-1091
Density Functional Theory employing hybrid and M06 functionals in combination with three different basis sets is used to calculate the ground state of a cage like (ZnO)12 nanocluster which has been consistently reported as the more stable cluster for its particular size. B3LYP and B3PW91 hybrid functionals combined with 6‐31+G*, Lanl2dz and SDD basis sets are employed to treat the ZnO molecular system. Alternatively, three M06 functionals in combination with three basis sets are employed in the nanostructure calculations. Results obtained by treating ZnO sodalite cage nanocluster with M06 functionals demonstrated comparable quality to results obtained with hybrid functionals. Within this study, efficient theoretical DFT methods with the widely known hybrid and the recently created M06 meta‐hybrid functionals are employed to study nanostructured ZnO. Our resulting parameters provide a fresh approach performance wise on the different theoretical methods to treat transition metal nanostructures, particularly, ZnO nanoclusters geometry and electronic structure. 相似文献
992.
Benoit Rigo Philippe Gautret Anne Legrand Samira El Ghammarti Daniel Couturier 《合成通讯》2013,43(18):2609-2615
Starting from the readily available N,O-bis trimethylsilyl pyroglutamate, an easy high yield one pot synthesis of ketone 1 was described. 相似文献
993.
Augusto Rivera Jaime Ríos-Motta Ginna Paola Trujillo Derly Marcela González Daniel Alcázar 《合成通讯》2013,43(6):791-799
A series of 2,2′-(dihydropyrimidine-1,3(2H,4H)-diyldimethanediyl)bis(substituted-phenols) was synthesized using a Mannich-type reaction between the macrocyclic aminal 1,3,7,9,13,15,19,21-octaazapentacyclo[19.3.1.13,7.19,13.115,19]octacosane (OAPO) (1) and substituted phenols in basic media. These previously unreported compounds were separated from the reaction mixture by column chromatography in highly pure form with 25–75% yields. The most stable conformer was predicted using AM1-type semiempirical quantum chemical calculations. 相似文献
994.
Daniel Wright Mariagioia Zampagni Elisa Evangelisti Simona Conti Giampiero D'Adamio Andrea Goti Matteo Becatti Claudia Fiorillo Niccolò Taddei Gianfranco Liguri 《Photochemistry and photobiology》2013,89(2):442-452
UV‐induced toxicity is characterized by marked oxidative stress, accompanied by the depletion of key cellular antioxidants, particularly glutathione (GSH). Replenishing cellular GSH may represent a means of counteracting UV‐induced toxicity: however, treatment with free GSH is not therapeutically effective due to its unfavorable pharmacokinetic properties. In this study, we show that S‐acyl‐glutathione (acyl‐SG) derivatives, which consist of an acyl chain (of variable length and saturation) linked via a thioester bond to GSH, increase intracellular levels of reduced GSH in primary skin fibroblasts, adenocarcinoma HeLa and neuroblastoma SH‐SY5Y cells. Consistent with this, acyl‐SG derivatives protect against UV‐induced reactive oxygen species (ROS) production and UV‐B/C‐mediated lipid peroxidation and caspase‐3 activation in the analyzed cell lines, with unsaturated thioesters displaying a significantly greater protective effect. Taken together, our findings suggest that acyl‐SG thioesters may be therapeutically effective in the treatment of UV‐related skin disorders and oxidative stress‐mediated conditions in general. 相似文献
995.
Air oxidation of N-cyclopropylanilines was shown to occur under either ambient conditions or accelerated conditions (warming or shining light) in an open container. A subsequent fragmentation resulted in formation of the corresponding acetamide. While potential mechanisms have been previously proposed, simple aerobic oxidation to β-hydroxy-propionamides in the absence of a radical promoter has not been previously reported. 相似文献
996.
Chlorosulfonyl isocyanata (CSI) reacts with 2H-azirines 1 a-c at -78°C to form [2+2+2] cycloadducts 3a-c and 4a-c. The tricyclic aziridine derivatives 4a-c undergo CSI extrusion reactions and subsequent oxidation to the corresponding pyrazines 5a-c. Structural identifications of 3a-c and 4a-c are based on ir, nmr and mass spectral data. 相似文献
997.
Daniel R. Zuidema Sarah L. Williams Katherine J. Wert Karin J. Bosma Abigail L. Smith Robert C. Mebane 《合成通讯》2013,43(19):2927-2931
Aryl ketones are readily deoxygenated to their corresponding aryl alkanes upon treatment with Raney nickel catalyst in boiling 2-propanol.
998.
We report here an efficient method for the synthesis and characterization of the room-temperature ionic liquid 1,3-di-n-butylimidazolium tribromide ([BBIm]Br3) (2) and its application as an efficient reagent and solvent for regioselective bromination of arylamines and phenols under mild conditions. The bromination was carried out in the absence of organic solvents, and in most cases, the only extraction solvent needed was water. The spent 1,3-di-n-butylimidazolium bromide (1) was easily recycled. 相似文献
999.
Condensation of 2-nitrothiophenol with ethyl propiolate afforded 3-(2-nitrophenylthio)propenoate. Oxidation of sulfur atom to sulfone group gave ethyl 3-(2-nitrophenylsulfonyl)propenoate, which underwent condensation with tosyl methylisocyanide (TosMIC) to yield ethyl 4-(2-nitrophenylsulfonyl)pyrrole-3-carboxylate. Reduction of nitro group afforded ethyl 4-(2-aminophenylsulfonyl)-1H-pyrrole-3-carboxylate, which was cyclized to 2H-pyrrolo[3,4-b][1,5] benzothiazepin-10(9H)-one 4,4-dioxide. Similar procedure was used for the synthesis of 9,10-dihydro-10-methyl-2H-pyrrolo[3,4-b][1,5]benzothiazepine 4,4-dioxide. 相似文献
1000.
Bromonitromethane, triethyl orthoformate and aniline react together, in a one-flask procedure, to afford the title compound. 相似文献