Hydrogen peroxide oxidations, catalyzed

Floyd. R. A., Soong. L. M., and Culver, P. L. Horseradish peroxidase/ hydrogen peroxide-catalyzed oxidation of the carcinogen M-hydroxy-Af-acetyl-2-aminofluorene as affected by cyanide and ascorbate. Cancer Res.. 36 1510-1519.1976. 

EFFECTS OF AMINES IN OXIDATION OF HYDROQUINONE WITH HYDROGEN PEROXIDE CATALYZED BY COPPER(H)... 

The observation that addition of imidazoles and carboxylic acids significantly improved the epoxidation reaction resulted in the development of Mn-porphyrin complexes containing these groups covalently linked to the porphyrin platform as attached pendant arms (11) [63]. When these catalysts were employed in the epoxidation of simple olefins with hydrogen peroxide, enhanced oxidation rates were obtained in combination with perfect product selectivity (Table 6.6, Entry 3). In contrast with epoxidations catalyzed by other metals, the Mn-porphyrin system yields products with scrambled stereochemistry the epoxidation of cis-stilbene with Mn(TPP)Cl (TPP = tetraphenylporphyrin) and iodosylbenzene, for example, generated cis- and trans-stilbene oxide in a ratio of 35 65. The low stereospecificity was improved by use of heterocyclic additives such as pyridines or imidazoles. The epoxidation system, with hydrogen peroxide as terminal oxidant, was reported to be stereospecific for ris-olefins, whereas trans-olefins are poor substrates with these catalysts. 

The most widely employed methods for the synthesis of nitrones are the condensation of carbonyl compounds with A-hydroxylamines5 and the oxidation of A+V-di substituted hydroxylamines.5 9 Practical and reliable methods for the oxidation of more easily available secondary amines have become available only recently.10 11 12 13. These include reactions with stoichiometric oxidants not readily available, such as dimethyldioxirane10 or A-phenylsulfonyl-C-phenyloxaziridine,11 and oxidations with hydrogen peroxide catalyzed by Na2W044 12 or Se02.13 All these methods suffer from limitations in scope and substrate tolerance. For example, oxidations with dimethyldioxirane seem to be limited to arylmethanamines and the above mentioned catalytic oxidations have been reported (and we have experienced as well) to give... 

Under microwave irradiation and applying MCM-41-immobilized nano-iron oxide higher activity is observed [148]. In this case also, primary aliphatic alcohols could be oxidized. The TON for the selective oxidation of 1-octanol to 1-octanal reached to 46 with 99% selectivity. Hou and coworkers reported in 2006 an iron coordination polymer [Fe(fcz)2Cl2]-2CH30H with fez = l-(2,4-difluorophenyl)-l,l-bis[(l//-l,2,4-triazol-l-yl)methyl]ethanol which catalyzed the oxidation of benzyl alcohol to benzaldehyde with hydrogen peroxide as oxidant in 87% yield and up to 100% selectivity [149]. An alternative approach is based on the use of heteropoly acids, whereby the incorporation of vanadium and iron into a molybdo-phosphoric acid catalyst led to high yields for the oxidation of various alcohols (up to 94%) with molecular oxygen [150]. 

ROO- + Au -OH — ROOM Au"-0 Scheme 2.8 Oxidation of alkanes with hydrogen peroxide catalyzed by gold(lll) and gold(l) complexes. 

Au "=0 species are postulated, inter alia, as active intermediates in the oxidation of alkanes with hydrogen peroxide catalyzed by gold(III) and gold(I) complexes [115]. The reaction sequence is proposed in Scheme 2.8. 

HTAC cationic micelles also markedly enhance the CL intensity of fluorescein (FL) in the oxidation of hydrogen peroxide catalyzed by horseradish peroxidase (HRP) [39], However, no CL enhancement was observed when anionic micelles of sodium dodecyl sulphate (SDS) or nonionic micelles of polyoxyethylene (23) dodecanol (Brij-35) were used (Fig. 9). CL enhancement is attributed to the electrostatic interaction of the anionic fluorescein with the HTAC micelles. The local concentration of fluorescein on the surface of the micelle increases the efficiency of the energy transferred from the singlet oxygen (which is produced in the peroxidation catalyzed by the HRP) to fluorescein. This chemiluminescent enhancement was applied to the determination of traces of hydrogen peroxide. The detection limit was three times smaller than that obtained in aqueous solution. 

Chromox [Chromium oxidation] A process for destroying organic pollutants in aqueous wastes by oxidation with hydrogen peroxide, catalyzed by Cr6+. Developed by British Nuclear Fuels in 1995, originally for use in nuclear reprocessing. 

Tyramide signal amplification This procedure, designated as a catalyzed reporter deposition (CARD) or tyramide signal amplification (TSA), takes advantage of horseradish peroxidase (HRP) from an HRP-labeled secondary antibody to catalyze in the presence of hydrogen peroxide the oxidation of the phenol moiety of labeled tyramine. On oxidation by HRP, activated tyramine molecules rapidly bind covalently to electron-rich amino acids of proteins immediately surrounding the site of the immunoreaction. This allows an increase in the detection of an antigenic site up to 100-fold compared with the conventional indirect method with no loss in resolution. 

MnP catalyzes hydrogen-peroxide-dependent oxidation of Mn to Mn, which in turn oxidizes phenolic components of lignin [102]. Oxidative demethylation, dechlorination, and decolorization of bleach plant effluent by the MnP of Phanerochaete chrysosporium has been demonstrated [103,104]. 

In 2003, Bernini and coworkers established a method for converting some flavonoid ketones into the corresponding lactones with hydrogen peroxide as oxidant catalyzed by MTO supported on poly(4-vinylpyridine) polymers (equation 82) °. Conversions and... 

We report here three studies that address three separate but significant issues in the emerging area of selective catalytic oxidation by TMSP-type complexes. The first study establishes for the first time that some TMSP complexes are compatible with basic oxidants and basic conditions. The second study reports the first oxidation, in this case selective alkene epoxidation, by the economically and environmentally desirable oxidant, aqueous hydrogen peroxide, catalyzed by TMSP complexes. The third study demonstrates that redox active polyoxometalates can be derivatized with alcohols in a manner that should prove useful for fabricating future generations of more sophisticated and selective TMSP catalysts. 

The discovery of titanium substituted ZSM-5 (TS-1) and ZSM-11 (TS-2) have led to remarkable progress in oxidation catalysis (1,2). These materials catalyze the oxidation of various organic substrates using aqueous hydrogen peroxide as oxidant. For example, TS-1 is now used commercially for the hydroxylation of phenol to hydroquinone and catechol (/). Additionally, TS-1 has also shown activity for the oxidation of alkanes at temperatures below 1()0 °C (3,4). 

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