Oxidative coupling of some 2,6-disubstituted phenol derivatives in perchloric acid mediated by cerium(IV) ions

摘要

2,6-Disubstituted phenol derivatives have been oxidized by cerium(IV) perchlorate in aqueous or aqueous-acetonitrile solutions of perchloric acid as well as in two-phase systems to the corresponding 1,4-benzoquinones, 4,4'-diphenoquinones, and oligomeric poly(1,4-phenylene) oxides in good yield. Nature and constitution of the oxidation products as a consequence of reaction conditions and physico-chemical properties of radicals and radical ions are reported. These properties are discussed in terms of stabilities, pK values, and electron densities at carbon C4 and oxygen. [References: 16]