Synthesis of Aryl-Platinum Dinuclear Complexes via <i>o</i><i>rtho</i> C−H Bond Activation of Phenol and Transmetalation of Arylboronic Acid

Abstract

The reaction of the pivalamidate-bridged platinum(III) dinuclear complex [Pt 2 (NH 3 ) 4 ( t BuCONH) 2 (OH 2 ) 2 ] 4+ with phenol in water gave 2-hydroxyphenyl platinum dinuclear complex [Pt 2 (NH 3 ) 4 ( t BuCONH) 2 (C 6 H 4 (OH))] 3+ via ortho C−H bond activation in the axial position. The identical compound and the analogous phenyl complex [Pt 2 (NH 3 ) 4 ( t BuCONH) 2 (C 6 H 5 )] 3+ could alternatively be synthesized from the reactions of [Pt 2 (NH 3 ) 4 ( t BuCONH) 2 (OH 2 ) 2 ] 4+ with the corresponding arylboronic acids via transmetalation. The reactivities of the novel aryl-Pt 2 compounds toward nucleophiles and the effect of UV light irradiation were investigated. The ESR spectra showed that the axial aryl−Pt bond is homolytically cleaved by UV light irradiation to give the aryl radical and the Pt(III)−Pt(II) paramagnetic complex.