69855-16-9Relevant articles and documents
A useful propionate cofactor enhancing activity for organic solvent-tolerant recombinant metal-free bromoperoxidase (perhydrolase) from Streptomyces aureofaciens
China, Hideyasu,Ogino, Hiroyasu
, p. 327 - 332 (2019/07/12)
The oxidative brominating activity of an organic solvent-tolerant recombinant metal-free bromoperoxidase BPO-A1 with C-terminal His-tag (rBPO-A1), from Streptomyces aureofaciens found to depend on various additives. These included carboxylic acids, used as cofactors and alcohols, used as water-miscible organic solvents. Enzyme activity was significantly enhanced by using propanoic acid (PA) as a cofactor, which had a high Log D at pH 5.0 and ethylene glycol with a low Log P. The positional specificity of oxidative hydroxybromination for olefins, using rBPO-A1 and PA in the presence of methanol, was higher compared to a non-enzymatic reaction using peracetic acid. The oxidative bromination step, occurring after enzymatic peroxidation step, is suggested to be pseudoenzymatic.
Oxidation of geraniol and other substituted olefins with hydrogen peroxide using mesoporous, sol-gel-made tungsten oxide-silica mixed oxide catalysts
Somma, Filippo,Strukul, Giorgio
, p. 344 - 351 (2007/10/03)
The preparation of a series of mesoporous tungsten oxide-silica mixed oxides by sol-gel methods under basic conditions is reported. Surface modification with methyl and 3-chloropropyl groups is possible in an amount between 10 and 40 mol% with respect to the silane precursor. The amount of polar organic functional groups controls the surface area, the porosity, and the catalytic activity of the solids in the oxidation of different substrates with hydrogen peroxide. The oxidation of geraniol is studied in detail. The catalysts are active and produce epoxides in good yields. The latter are influenced by the presence of polar organic groups. The preparation method allows the preparation of catalysts that are resistant to leaching and can be recycled several times without appreciable loss of activity.
Selective epoxidation of monoterpenes with H2O2 and polymer-supported methylrheniumtrioxide systems
Saladino, Raffaele,Neri, Veronica,Pelliccia, Anna Rita,Mincione, Enrico
, p. 7403 - 7408 (2007/10/03)
A convenient and efficient synthesis of monoterpene epoxides by application of heterogeneous poly(4-vinylpyridine)/methyl rhenium trioxide (PVP/MTO) and polystyrene/methyl rhenium trioxide (PS/MTO) systems is described. Even highly sensitive terpenic epoxides were obtained in excellent yield. Environment friendly, easily available, and low cost H2O2 was used as oxidant. Catalysts were stable systems for at least five recycling experiments.
Selective epoxidation of monoterpenes with methyltrioxorhenium and H2O2
Villa De P., Aida L.,De Vos, Dirk E.,Montes De C., Consuelo,Jacobs, Pierre A.
, p. 8521 - 8524 (2007/10/03)
In the presence of pyridine as a co-catalyst, CH3ReO3 catalyses the epoxidation of terpenes such as α-pinene with H2O2 with minimal rearrangement of the epoxide. Pyridine is also critical to suppress isomerisation of the olefin substrate (in case of nerol, geraniol). The reaction can be directed towards selective single or double epoxidation, or in one step towards the rearranged product (e.g. from linalool to the ring- closure product linalool oxide.
Oxidations with hydrogen peroxide catalysed by the [WZnMn(II)2(ZnW9O34)2]12- polyoxometalate
Neumann,Juwiler
, p. 8781 - 8788 (2007/10/03)
Polyoxometalates can be used as catalysts for the activation of molecular oxygen and 30% aqueous hydrogen peroxide for the selective transformation of various organic substrates. In this paper results are presented for the oxidation of alkenes, dienes, alkenols, and sulfides using 30% aqueous H2O2 as oxidant and [WZnMn(II)2(ZnW9O34)2]12- as catalyst. In certain but not all cases high reactivity, chemoselectivity and stereospecificity has been observed especially in the epoxidation of alkenols with primary hydroxyl units.
