Synthesis of Unsymmetrical Biphenyls by Reaction of Nitroarenes with Phenols

Article abstract of DOI:10.1021/jo00217a016

The anion of 2,6-di-tert-butylphenol (1) behaves as a carbon nucleophile toward nitroarenes bearing leaving groups ortho or para to the nitro group, affording biphenyls by conventional S_NAr processes.However, 1 reacts with m-dinitrobenzene (2), o-nitrobenzonitrile, or m-nitrobenzonitrile to give biphenyls by displacements of nitroarene hydrogen atoms.This oxidative coupling process also occurs between unhindered phenols, even phenol itself, and compound 2.Mechanistic features of the oxidative coupling reaction are discussed.