نتایج جستجو برای: epoxidation
تعداد نتایج: 1907 فیلتر نتایج به سال:
Oxidation of functioning copper has restricted its applicability as a catalyst for commercially important epoxidation of propylene to form propylene oxide. Here, we report that steady-state selectivity in propylene epoxidation on copper (Cu) nanoparticles increases sharply when the catalyst is illuminated with visible light. The selectivity increase is accompanied by light-induced reduction of ...
Silica-supported molybdenum surface complexes were prepared by the reaction between (N=)Mo(OtBu)3 and silica via displacement of the tert-butoxy ligands for siloxyls from the silica surface. The structure of the surface molybdenum complexes was well defined by in-situ FT-IR, elemental analysis, H NMR and C CP/MAS NMR techniques. The surface complexes could undergo alcoholysis reaction with CD3O...
Article history: Received 13 April 2010 Accepted 28 April 2010 Available online 16 June 2010 Dedicated to Henri Kagan on the occasion of his 80th birthday 0957-4166/$ see front matter 2010 Elsevier Ltd. A doi:10.1016/j.tetasy.2010.04.046 * Corresponding author. Tel.: +44 117 954 6315; fa E-mail address: [email protected] (V.K. Agg The epoxidation of meroquinene aldehyde with a chiral sul...
Epoxides are an important class of industrial chemicals that have been used as chemical intermediates. Catalytic epoxidation of olefins affords an interesting production technology. We found a widely usable green route to the production of epoxides: A silicotungstate compound, [gamma-SiW10O34(H2O)2]4-, is synthesized by protonation of a divacant, lacunary, Keggin-type polyoxometalate of [gamma-...
Highly selective photocatalytic epoxidation of olefins proceeds on Ti-containing silica with tetrahedrally coordinated Ti-oxide species with molecular oxygen and a simple addition of MeCN.
The remarkable catalytic activity of the saturated metal organic framework MIL-47 in the epoxidation of cyclohexene is elucidated by means of both experimental results and theoretical calculations.
trifluoromethylated organic compounds, especially chiral quaternary alcohols bearing trifluoromethyl group are of important intermediates in drugs, agrochemicals and etc.an efficient epoxidation of β-cf3-β,β-disubstituted unsaturated ketones (6) has been developed with environmental benign hydrogen peroxide as the oxidant and f5-substituted chiral quaternary ammonium salt (1g or 5) derived from...
kinetic study of epoxidation of unsaturated ketone of mesityl oxide was studied by usinghydrogen peroxide in the presence of dodecyltrimethyl ammonium bromide (dtab) as aninverse phase transfer catalyst. the reaction was carried out in the two-phase media of waterheptanewith 1:1 ratio in 25 °c. it was found that the order of reaction for mesityl oxide forketone concentration in the range of 0.0...
Through catalytic epoxidation and aziridination of olefins versatile synthetic intermediates and subunits of biologically active compounds and pharmaceuticals –epoxides and aziridines– can be obtained. The focus of this review is on recent advances in the epoxidation and aziridination of challenging terminal alkenes with respect to safety of solvents or reagents used and atom economy aspects, a...
90 A practical method of olefin epoxidation was developed by combining FeCl3·6H2O and 1methylimidazole in acetone using H2O2 as the terminal oxidant. This system showed very good reactivity toward epoxidation of both terminal and substituted alkenes. The use of tridentate and tetradentate amine-bis(phenolate) ligands as additives was also examined. Modest improvement in selectivity was achieved...
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