Hydrogen bonded intermediates peroxidation products

The first step in the peroxide-induced reaction is the decomposition of the peroxide to form a free radical. The oxygen-induced reaction may involve the intermediate formation of a peroxide or a free radical olefin-oxygen addition product. (In the case of thermal and photochemical reactions, the free radical may be formed by the opening up of the double bond or, more probably, by dissociation of a carbon-hydrogen bond in metal alkyl-induced reactions, decomposition of the metal alkyl yields alkyl radicals.)... 

The XH can be the parent hydrocarbon but is more usually an intermediate oxidation product with weaker C—H bonds, such as an aldehyde or alkene. Even so, the abstraction reaction has a large activation energy, as does the hydrogen peroxide decomposition (which is also pressure dependent), so that the branching mechanism tends to be of greater importance towards the higher temperature and pressure part of the region. 

In addition to the oxymercuration method, which yields the Markovnikov product, a complementary method that yields the non-Markovnikov product is also useful. Discovered in 1959 by H. C. Brown and cailed hydroboration, the reaction involves addition of a B-H bond of borane, BH3, to an alkene to yield an organoborane intermediate, RBH2. Oxidation of the organoborane by reaction with basic hydrogen peroxide, H2O2, then gives an alcohol. For example ... 

Here we presented two general aspects of the interactions between superoxide and metal centers. One is the catalytic decomposition of superoxide by non-heme metal centers (Scheme 9) and the role of the ligand structure in it, and another is the reversible binding of superoxide to the heme metal center and the nature of the product metal(lll)-peroxo species (Scheme 17). In both cases through the same redox reaction steps a metal(III)-peroxo species is formed as the intermediate (Scheme 9), in the catalytic cycle, or the product of stoichiometric reaction (Scheme 17). The crucial difference is in the protonation step. If the protonation of peroxo species is followed by efficient release of hydrogen peroxide (and not 0-0 bond cleavage,... 

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