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81.
Xiao-Feng Wu 《Tetrahedron letters》2012,53(45):6123-6126
A zinc-catalyzed oxidation of benzylic substrates has been developed. The corresponding carbonyl containing compounds have been produced in moderate to excellent yields. Both arenes and heteroarenes can be applied as substrates by using H2O2 as the oxidant. 相似文献
82.
A mild and highly chemoselective method for the preparation of oxathiolane from aliphatic and aromatic aldehydes and ketones with 2-mercaptoethanol in the presence of catalytic amount of N-bromosaccharin at room temperature is reported. 相似文献
83.
Perfluorinated benzocycloalkenes (benzocyclobutene, indan, tetralin), alkylbenzocycloalkenes and alkylbenzenes react with CF3COOH/SbF5 at 20-50 °C giving the corresponding carbonyl derivatives. 相似文献
84.
Subhabrata Chaudhury Dennis W. Bennett Tasneem A. Siddiquee 《Journal of organometallic chemistry》2004,689(9):1437-1443
Tricarbonyl(1-methoxycarbonyl-5-phenylpentadienyl)iron(1+) hexafluorophosphate (7) was prepared in two steps from tricarbonyl(methyl 6-oxo-2,4-hexadienoate)iron. While addition of carbon and heteroatom nucleophiles to 7 generally occurs at the phenyl-substituted dienyl carbon to afford (2,4-dienoate)iron products, the addition of phthalimide proceeded at C2 to afford a (pentenediyl)iron product (18). Complex 18 was structurally characterized by X-ray diffraction analysis. 相似文献
85.
T.I. Gorbanyuk A.A. Evtukh V.G. Litovchenko V.S. Solntsev 《Physica E: Low-dimensional Systems and Nanostructures》2007,38(1-2):211
The effect of hydrogen sulphide on the current–voltage characteristics of metal–insulator–semiconductor (MIS) structures based on nanoporous silicon (Sinanopor) under copper doping has been investigated. Scanning electron (SEM), atomic force (AFM) and optic microscopes and/or secondary ion mass spectroscopy (SIMS) were used to obtain detailed characterisation of copper cluster distribution present at the surface and pores, respectively. SIMS spectra reveal that finite gradient in copper distribution along the pores and oxidation of nanoporous silicon simultaneously can be obtained successfully under electroless deposition process. It was also shown that the doping of nanoporous silicon by Cu leads to enhanced hydrogen sulphide sensitivity of MIS structures even without catalytic active top electrodes (for example, Pd) at room temperature. Furthermore, for different types of familiar MIS structures based on nanoporous silicon, e.g., MIS structures doped or undoped by copper and by using Pd metal electrodes, the hydrogen sulphide detection at room temperature mainly depends on the modification in the height of barrier of hetero- (Al–Cu–Sinanopor–c-Si) or Schottky-like (Pd–Cu–Sinanopor–c-Si) structures resulting the chemical interaction of molecular H2S gas with copper clusters at the surface and in the pores. It is demonstrated that MIS structures based on the nanoporous silicon with copper doping are more sensitive to H2S action at room temperature. In addition, the physical mechanism explaining the observed phenomena is also discussed. 相似文献
86.
One-pot three-component Kabachnik-Fields synthesis of α-aminophosphonates with high yields from the reaction between carbonyl compound, primary amine, and substituted phosphite can be carried out in a short period, using H-beta zeolite as a reusable catalyst. 相似文献
87.
Martijn A. Zwijnenburg Robert G. Bell Furio Corà 《Journal of solid state chemistry》2008,181(9):2480-2487
The energetics, structure and physical properties of tetragonal and orthorhombic SiS2 were calculated by periodic density functional theory (DFT) calculations, using both localized orbital and projected augmented wave basis-sets. All methods applied agree upon the relative energies of the different polymorphs but show differences in the predicted geometries, which are minimized upon improving the basis-set quality. The hybrid PBE0 functional was found to give the best match between experimental and calculated structures. When comparing SiS2 with its much better studied oxide analog silica, we observe that upon substituting sulphur for oxygen, the energy landscape changes dramatically. Other effects of changing S for O are found to be smaller Si-X-Si angles, a broader distribution of X-Si-X angles, a more flexible framework and a significantly reduced band gap. The latter is in line with the experimental observation of photoluminescence in related GaGeS2 compounds and suggests that SiS2 might find application in UV light emitting diodes. Finally, a comparison of the maximally localized Wannier functions demonstrates that the Si-S bonds in SiS2 have a considerably more covalent character than the Si-O bonds in silica. 相似文献
88.
Potassium phthalimide was found to be a highly effective and easily accessible organocatalyst for the cyanosilylation of various carbonyl compounds under extremely mild conditions. The corresponding cyanohydrin trimethylsilyl ethers were obtained in high to quantitative yields in solvent-free conditions at room temperature using 2.5 mol% catalyst loading. 相似文献
89.
90.
A simple, environmentally benign protocol for synthesis of hydrazones from carbonyl compounds and hydrazides has been developed in the presence of meglumine in aqueous-ethanol media at room temperature. The salient features of the present protocol are mild reaction conditions, short reaction time, high yields, operational simplicity, metal-free, applicability toward large-scale synthesis, and biodegradable and inexpensive catalyst. 相似文献