Mixed Peroxidation

Dimethyl-2-hydroperoxide-5-ierr-butylperoxyhexane contains both a peroxy and a hydroperoxy group. The enthalpy of reaction 5, to give 2,5-dimethyl-2-hydroxy-5-f-butylperoxyhexane, is —59.9kJmoR (Iq) and —58.8kJmol (g), comparable to those obtained from 1-methylcyclohexane hydroperoxide and f-butyl hydroperoxide. If the mixed peroxide were to undergo the formal reactions 5 and 6 simultaneously, the alcohol product would be 2,5-dimethylhexane-2,5-diol, for which there is only an enthalpy... 

The synthesis of mixed peroxides formed from /-butyl hydroperoxide and carbon-centred radicals has been studied. The reactions were strongly effected by solvents as well as catalytic amounts of Cun/Fem. The kinetic data suggest that the conditions for the Ingold-Fischer persistent radical effect are fulfilled in these cases.191 The use of Cu /Cu" redox couples in mediating living radical polymerization continues to be of interest. The kinetics of atom-transfer radical polymerization (ATRP) of styrene with CuBr and bipyridine have been investigated. The polymer reactions were found to be first order with respect to monomer, initiator and CuBr concentration, with the optimum CuBr Bipy ratio found to be 2 1.192 In related work using CuBr-A-pentyl-2-... 

Bougioukou DJ, Smonou I (2002) Mixed Peroxides from the Chloroperoxidase-Catalyzed Oxidation of Conjugated Dienoic Esters with a Trisubstituted Terminal Double Bond. Tetrahedron Lett 43 4511... 

At least five detailed mechanisms have been proposed for bacterial luciferase within the last six years (28, 47, 48, 49, 50). With the assumption that our biomimetic model relates to the enzyme-catalyzed reaction, we conclude that these five proposals of mechanisms are incorrect. Four (28, 47,48) are inconsistent with the intermediacy of the mixed peroxide (4a-FlEt—O—O—CH(OH)R ) and cannot be applied to N(5)-alkylflavins. In addition, two (28, 47) of these mechanisms as well as another (49), require the hydroxyl group of the aldehyde-peroxide adduct. No mechanism can be taken seriously without the identification of the excited species. We do know that a hydrogen substituted is required on the carbon that is converted to a carbonyl group (47). 

The mixed peroxides, t-butylperoxy 2-ethylhexyl, (I), and isobutanoyl-lauroyl peroxide, (II), were prepared by Overkamp [2] and Tammer [3], respectively, using t-butyl peroxide and isobutanoyl chloride with 30% hydrogen peroxide in the presence of sodium hydroxide in a two-phase system. Both agents were used in vinyl chloride polymerization. 

The Kharasch-Sosnovsky reaction may be carried out in the presence of carboxylic acids to introduce the acyloxy moiety of the acid used, and may also be conducted photochemically at room temperature using UV irradiation. Peioxy acids,diacyl peroxides, and peroxyphosphates and peroxyphospho-nates are alternative oxidants. /-Butyl hydroperoxide may also be used in place of peroxy esters with broadly similar results, although formations of mixed peroxides and /-butyl ethers can then compete with allyl ester production. 

Carboxy-inversion reaction. Denney and Sherman found that m-chloroperbenzoic acid (2) reacts readily with a carboxylic acid chloride (1) in hexane solution at 0 in the presence of pyridine to form a mixed peroxide (3). When the mixture is stirred for several hours at room temperature the peroxide rearranges to the mixed carbonate... 

Alkyl hydroperoxides. Alkylation of this easily handled hydroperoxide with alkyl halides furnishes mixed peroxides that are selectively hydrolyzed in aqueous acetic acid. The reagent is obtained in 53% yield by ozonolysis of 2,3-dimethyl-2-butene in neat 2-methoxyethanol, followed by dilution with water, extraction with EtOAc, and evaporation. It should be noted that the simpler 2-methoxyprop-2-yl... 

The autoxidation of benzaldehyde produces perbenzoic acid as the primary product. This peracid reacts very rapidly with anhydrides to produce a mixed peroxide [44] and, in this case, an oxygen molecule is absorbed by benzaldehyde to produce two molecules of acid. According to Wittig and Pieper [12], the transformation probably takes place via the X peroxide intermediate which, however, has never been isolated. 

However, if the finish is to be cured at room temperature, there is no peroxide which can, on the one hand, remain relatively stable in the activator pack and, on the other, produce free radicals fast enough to give rapid hardening when activator and finish are mixed. Peroxide decomposition is accelerated by the addition of a metal salt from the drier range. The mechanism of the catalysis is as given in Chapter 12 for hydroperoxides. The combination of cobalt and either of the above ketone peroxides is widely used. Another combination is benzoyl peroxide and a tertiary amine, but this has the drawback that the films produced are prone to yellowing. 

Manganese, on the other hand, catalyzes a different reaction. It reshuffles the bonds in H Oj (peroxide) to make H O and O. Chemistry professors impress their classes by mixing peroxide with manganese oxide in a flask, which creates an explosive plume of water. True to oxygen s double-edged nature, this is dangerous, so I am happy to show it on video. 

L. B. Gan, S. Huang, H. X. Zhang, A. X. Zhang, B. C. Cheng, H. Cheng, X. L. Li, and G. Shang, Fullerenes as a tcrt-butylperoxy radical trap, metal catalyzed reaction of ferf-butyl hydroperoxide with fullerenes, and formation of the first fullerene mixed peroxides C6o(0)(OOfBu)4 and C7o(OOfBu)10. Journal of the American Chemistry Society, 124 (2002), 13384-5. 

Suspension Polymerization of Vinyl Chloride with Mixed Peroxides. 387... 

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