Peroxides, aromatic acyl, decomposition

Decomposition of Aromatic Acyl Peroxides. The decomposition of aromatic acyl peroxides in liquid aromatic compounds is similar to the decomposition of nitrosoacetylarylamines and appears to involve the intermediate formation of free radicals. When dibenzoyl peroxide is heated in benzene, biphenyl, benzoic acid, and small amounts of phenyl benzoate, p-terphenyl, and quaterphenyl are produced. 4 That the second component enters into the reaction is shown by the formation of 4-chlorobiphenyl from the decomposition of di-p-chlorobenzoyl peroxide in benzene 84 and of dibenzoyl peroxide in-chlorobenzene 86... 

A facile conversion of several aliphatic and aromatic acyl peroxides, halides, and anhydrides to the "per" acids has been effected by treatment with H2O2 and a threefold excess of base in the presence of a soluble magnesium saltl > The magnesium salt Is proposed to stabilize the "per" acid as it is formed, and to prevent its decomposition. 

The alkylation of aromatic nitro compoimds and of quinones has been accomplished by means of the radicals liberated by the decomposition of tetravalent lead salts of oi anic acids or of acyl peroxides, or by the electrolysis of sodium salts of organic acids. ... 

In this protocol, cyclohexanone peroxide and 2-methyl-l-oxa-2-azaspiro[2.5]octane were used, in the presence of Fe(II) salt, as free-radical sources. Afterward, in 1969 Caronna et al. reported the acylation of aromatic bases by acyl radicals (Scheme 7(c)) [2], The nucleophilic character of acyl radicals, generated in situ by Fe(II)-mediated hydroperoxide decomposition (Scheme 7(a) and (b)), was demonstrated to play the key role in the process. 

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