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Alkene Epoxidation (alkene + epoxidation)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

ChemInform Abstract: Biomimetic Alkene Epoxidation and Alkane Hydroxylation with Sodium Periodate Catalyzed by Mn(III)-Salen Supported on Amberlite IRA-200.

CHEMINFORM, Issue 10 2008
Valiollah Mirkhani
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

An Environmentally Benign Catalytic System for Alkene Epoxidation with Hydrogen Peroxide Electrogenerated in situ.

CHEMINFORM, Issue 8 2007
Kam-Piu Ho
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

A Novel Catalyst for Alkene Epoxidation: A Polymer-Supported CoIILCl2 {L = 2-(Alkylthio)-3-phenyl-5- (pyridine-2-ylmethylene)-3,5-dihydro-4H-imidazole-4-one} Complex.

CHEMINFORM, Issue 31 2006
Elena K. Beloglazkina
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

An Improved Protocol for the Ruthenium(pybox)-Catalyzed Asymmetric Alkene Epoxidation.

CHEMINFORM, Issue 52 2003
Man Kin Tse
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Activation Parameters for the Epoxidation of Substituted cis/trans Pairs of 1,2-Dialkylalkenes by Dimethyldioxirane

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 20 2006
Brian S. Crow
Abstract The first activation parameter data for the reaction of dimethyldioxirane (1) with five cis/trans pairs of alkenes are reported. The epoxidation of cis -1,2-dialkylalkenes (2cis: R1 = Me, R2 = iPr; 3cis: R1 = Me, R2 = tBu; 4cis: R1 = R2 = Et; 5cis: R1 = Et, R2 = iPr; 6cis: R1 = Et, R2 = tBu) and trans -1,2-dialkylalkenes (2trans: R1 = Me, R2 = iPr; 3trans: R1 = Me, R2 = tBu; 4trans: R1 = R2 = Et; 5trans: R1 = Et, R2 = iPr; 6trans: R1 = Et, R2 = tBu) by 1 produced the corresponding epoxides, quantitatively and stereospecifically, as the sole observable products. Activation parameters of the epoxidation of the five pairs of alkenes, 2cis,6cis and 2trans,6trans, by 1 were determined using the Arrhenius method. Enhanced selectivity for cis - vs. trans -alkene epoxidation was observed at lower temperatures. In general, the ,G, terms were larger and showed more variability for the reaction of 1 with trans -alkenes as compared to those for the corresponding cis isomers. The ,H, terms mirrored trends observed in ,G, because ,S, terms for all ten of the compounds were roughly identical. The ,,G, values, a comparison of the trans to the cis isomer data, yielded positive values of 1.2 to 1.8 kcal/mol for the five sets of data and appeared to be dependent on relative steric interactions. The experimental activation parameter data, consistent with predictions from ab initio calculations based on a spiro transition-state model, showed that the lower reactivity of trans -alkenes is due to enthalpy factors. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]

Photovoltaic activity of Ti/MCM-41

CHEMPHYSCHEM, Issue 1 2009
Pedro Atienzar Dr.
Abstract Ti/MCM-41 is a well-known heterogeneous catalyst for alkene epoxidation with organic peroxides. This titanosilicate contains isolated titanium atoms forming part of a framework of mesoporous silica whose structure is formed by parallel hexagonal channels 3.2 nm in diameter. The surface area and porosity of Ti/MCM-41 are about 880 m2,g,1 and 0.70 cm3,g,1, respectively. These values are among the highest for any material. Herein, we show that Ti/MCM-41 exhibits photovoltaic activity. Dye-sensitized solar cells using mesoporous Ti/MCM-41 (2.8,5.7,% Ti content) as active layer, black dye N3 as photosensitizer and I3,/I, in methoxyacetonitrile as electrolyte exhibit a VOC, JSC and FF of 0.44 V, 0.045 mA,cm,2 and 0.33, respectively. These values compare well against 0.75 V, 4.1 mA,cm,2 and 0.64, respectively, measured for analogous solar cells using conventional P-25 TiO2. However, the specific current density (JSC/Ti atom) for the Ti/MCM-41 is very similar to that of P25 TiO2. [source]