Epoxide peroxide

For analysis of dienes and polyenes via oxidations one has to distinguish between the formation of an oxidized product of the target molecule (epoxide, peroxide, ozonide etc.) and the oxidative fragmentation of the molecule as in the case of ozonolysis30. Both... 

As a resirlt of the differences in polarity between the carbon fluorine and the carbon-hydrogen bond, fluorocarbon chemistry is wrought with more differences than similarities to hydrocarbon chemistry despite their similarities in van der Waal s radii (1.20 vs. 1.35 A). A great body of chemistry for the functionalized fluorocarbons has been developed in the areas of perfluoroalkenes, halofluoroalkanes, ethers, epoxides, peroxides, ketones, acids, and esters. 

Oxyfluorides of Carbon. The literature on compounds containing only carbon, oxygen, and fluorine is extensive, numerous reviews are available, and many compounds are of industrial importance. Functional groups included under this classification are ketones, acid fluorides, ethers, epoxides, peroxides, and hypofluorites. Only very simple molecules are mentioned here as representatives of this large class of compounds. 

Other groups of compounds are known to react together rapidly and exothermically. These include mixtures such as acids and bases, acids and metals, fuels and oxidants, free radical initiators and epoxides, peroxides, or unsaturated molecules. 

Two geometries are also possible in the hydrogen bonding of 4-fluorophenol to epoxides, peroxides and sterically hindered ethers . The most stable complex has geometry 49, and the least stable one the trigonal geometry 50. 

Cytochrome P-450 has an iron-porphyrin complex as active site and is able to catalyse a great many chemical reactions as hydroxylation of aromatics and aliphatics, N- and S-oxidation, epoxidation, peroxidation, N-, S- and 0-dealkylation, deamination, desulphuration and dehalogenation. 

The P450s catalyze a variety of reactions, including hydroxylation, epoxidation, peroxidation, sulfoxidation, dealkylation, deamination, etc., depending on the substrate structures. Many substrates, including alkenes, aromatic hydrocarbons, heterocycles, vinyl halides, e yl carbamate, vinyl nitrosamines, and aflatoxin Bl, have been epoxi-dized with good stereoselectivities by the membrane-boimd mammalian P450s [29]. 

ARCO has developed a coproduct process which produces KA along with propylene oxide [75-56-9] (95—97). Cyclohexane is oxidized as in the high peroxide process to maximize the quantity of CHHP. The reactor effluent then is concentrated to about 20% CHHP by distilling off unreacted cyclohexane and cosolvent tert-huty alcohol [75-65-0]. This concentrate then is contacted with propylene [115-07-1] in another reactor in which the propylene is epoxidized with CHHP to form propylene oxide and KA. A molybdenum catalyst is employed. The product ratio is about 2.5 kg of KA pet kilogram of propylene oxide. 

The reaction of perfluoroalkenes with alkaline hydrogen peroxide is a good general method for the preparation of the corresponding epoxides with the exception of the most reactive of the series, TFEO (eq. 6). 

The alkene is allowed to react at low temperatures with a mixture of aqueous hydrogen peroxide, base, and a co-solvent to give a low conversion of the alkene (29). These conditions permit reaction of the water-insoluble alkene and minimise the subsequent ionic reactions of the epoxide product. Phase-transfer techniques have been employed (30). A variation of this scheme using a peroxycarbimic acid has been reported (31). 

Tetrafluoroethylene undergoes addition reactions typical of an olefin. It bums in air to form carbon tetrafluoride, carbonyl fluoride, and carbon dioxide (24). Under controlled conditions, oxygenation produces an epoxide (25) or an explosive polymeric peroxide (24). Trifluorovinyl ethers,... 

R, R -Tartaric (racemic) acid is obtained synthetically by epoxidation of maleic acid with hydrogen peroxide in the presence of a catalyst followed... 

N—Fe(IV)Por complexes. Oxo iron(IV) porphyrin cation radical complexes, [O—Fe(IV)Por ], are important intermediates in oxygen atom transfer reactions. Compound I of the enzymes catalase and peroxidase have this formulation, as does the active intermediate in the catalytic cycle of cytochrome P Q. Similar intermediates are invoked in the extensively investigated hydroxylations and epoxidations of hydrocarbon substrates cataly2ed by iron porphyrins in the presence of such oxidizing agents as iodosylbenzene, NaOCl, peroxides, and air. 

Arsenic Peroxides. Arsenic peroxides have not been isolated however, elemental arsenic, and a great variety of arsenic compounds, have been found to be effective catalysts ia the epoxidation of olefins by aqueous hydrogen peroxide. Transient peroxoarsenic compounds are beheved to be iavolved ia these systems. Compounds that act as effective epoxidation catalysts iaclude arsenic trioxide, arsenic pentoxide, arsenious acid, arsenic acid, arsenic trichloride, arsenic oxychloride, triphenyl arsiae, phenylarsonic acid, and the arsenates of sodium, ammonium, and bismuth (56). To avoid having to dispose of the toxic residues of these reactions, the arsenic can be immobi1i2ed on a polystyrene resia (57). 

Obsolete uses of urea peroxohydrate, as a convenient source of aqueous hydrogen peroxide, include the chemical deburring of metals, as a topical disinfectant and mouth wash, and as a hairdresser s bleach. In the 1990s the compound has been studied as a laboratory oxidant in organic chemistry (99,100). It effects epoxidation, the Baeyer-Villiger reaction, oxidation of aromatic amines to nitro compounds, and the conversion of sodium and nitrogen compounds to S—O and N—O compounds. 

Because di-/ fZ-alkyl peroxides are less susceptible to radical-induced decompositions, they are safer and more efficient radical generators than primary or secondary dialkyl peroxides. They are the preferred dialkyl peroxides for generating free radicals for commercial appHcations. Without reactive substrates present, di-/ fZ-alkyl peroxides decompose to generate alcohols, ketones, hydrocarbons, and minor amounts of ethers, epoxides, and carbon monoxide. Photolysis of di-/ fZ-butyl peroxide generates / fZ-butoxy radicals at low temperatures (75), whereas thermolysis at high temperatures generates methyl radicals by P-scission (44). 

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