114701-53-0Relevant articles and documents
Highly facile homogeneous epoxidation of olefins using oxo-diperoxo tungstate(VI) complex as catalyst, bicarbonate as co-catalyst and hydrogen peroxide as a terminal oxidant
Maiti, Swarup K.,Dinda, Subhajit,Gharah, Narottam,Bhattacharyya, Ramgopal
, p. 479 - 489 (2007/10/03)
Addition of a dilute acetic acid solution of 8-quinolinol to an H 2O2 solution of freshly precipitated H2WO 4·2H2O furnishes a yellow adduct [WO(O 2)2·2QOH] 1 which, on crystallization from a suitable solvent, affords orange-yellow complex [WO(O2)(QO) 2] 2. When 2 reacts stoichiometrically with olefinic compounds in a 1:1 molar ratio, the respective olefins are epoxidized and 2 is converted to the orange-red [WO2(QO)2] 3. When 1 is treated with an excess of H2O2 (greater than 6 equiv.) and PPh4Cl, an anionic light yellow complex PPh4[WO(O2)2(QO)] 4 is obtained. 4 reacts with cyclopentene (a representative olefin) in a 1:1 molar ratio producing cyclopentene oxide and itself is converted to PPh 4[WO2(O2)(QO)] 5. If the above reaction is conducted at a 1:2 molar ratio (instead of 1:1) then 2 moles of the corresponding epoxide is formed and 4 is converted to PPh4[WO 3(QO)] 6. All these peroxo complexes have remarkable catalytic efficiencies in the epoxidation of olefinic compounds when used in tandem with NaHCO3 as co-catalyst and H2O2 as oxidant in a CH3CN medium at room temperature, the method being green and economical. The catalyst 4 under the above experimental conditions shows so far unmatched efficiency in epoxidizing a wide variety of olefinic substrates. the Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2006.
A Novel Oxidation of Internal Alkynes with Hydrogen Peroxide Catalyzed by Peroxotungsten Compounds
Ishii, Yasutaka,Sakata, Yasuyuki
, p. 5545 - 5547 (2007/10/02)
Internal alkynes underwent a novel oxidation with aqueous hydrogen peroxide catalyzed by peroxotungsten compounds under two-phase conditions using chloroform as the solvent, giving α,β-epoxy ketones and α,β-unsaturated ketones as principal products.The epoxidation of α,β-unsaturated ketones by this catalyst-oxidant system appeared to involve the electrophilic attack of the peroxo species to the double bond.