Selective oxidative para C–C dimerization of 2,6-dimethylphenol

Mechanistic investigations on the oxidative coupling of 2,6-dimethylphenol have led to the development of a selective and efficient procedure to prepare 3,5,3ʹ,5ʹ-tetramethyl-biphenyl-4,4ʹ-diol, via a C–C coupling, mediated by a hypervalent form of iodine, i.e. (diacetoxyiodo)benzene and for which a mechanism is proposed.