نتایج جستجو برای: epoxidation

تعداد نتایج: 1907  

Journal: :Science 2013
Andiappan Marimuthu Jianwen Zhang Suljo Linic

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 ...

2003
Qihua Yang Christophe Copéret Can Li Jean-Marie Basset

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...

2010
Muhammad Arshad M. Alejandro Fernández Eoghan M. McGarrigle Varinder K. Aggarwal

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...

Journal: :Science 2003
Keigo Kamata Koji Yonehara Yasutaka Sumida Kazuya Yamaguchi Shiro Hikichi Noritaka Mizuno

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-...

Journal: :Chemical communications 2005
Yasuhiro Shiraishi Masatsugu Morishita Takayuki Hirai

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.

Journal: :Chemical communications 2010
Karen Leus Ilke Muylaert Matthias Vandichel Guy B Marin Michel Waroquier Veronique Van Speybroeck Pascal Van der Voort

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.

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2015
shaoxiang wu qi wang yao-feng wang pran gopal karmaker fu-xue chen

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...

Journal: :journal of the iranian chemical research 0
mohammad taghi taghizadeh department of physical chemistry, faculty of chemistry, university of tabriz, tabriz, iran tahere shaidaii department of physical chemistry, faculty of chemistry, university of tabriz, tabriz, iran narges sabouri department of physical chemistry, faculty of chemistry, university of tabriz, tabriz, iran

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...

2015
Anja Fingerhut Olga V. Serdyuk Svetlana B. Tsogoeva

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...

2010
Kamrul Hasan Nicole Brown Christopher M. Kozak

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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