Oxidative phenol-arene and phenol-phenol cross-coupling using periodic acid

Abstract A simple, metal-free protocol for unsymmetrical biaryl coupling using H 5 IO 6 is reported. H 5 IO 6 was evaluated for a novel application in the oxidative cross-coupling of phenol-arene, phenol-phenol, and phenol-naphthol compounds. In this work, most of the couplings were completed within 30 min at ambient temperature. 30 coupling products were conveniently obtained using only 0.5 equivalent of H 5 IO 6 in HFIP. A mechanism by which the transformation occurs is proposed.