Inter- and Intramolecular Activation of Aromatic C−H Bonds by Diphosphine and Hydrido-Bridged Dinuclear Iridium Complexes

Reactions of [(Cp*Ir)2(μ-dmpm)(μ-H)2]2+ (1) with NaO t Bu in aromatic solvent at room temperature give [(Cp*Ir)(H)(μ-dmpm)(μ-H)(Cp*Ir)(Ar)]+ [Ar = Ph (3), p-Tol (4a), m-Tol (4b), 2-furanyl (5a), 3-furanyl (5b)] via intermolecular aromatic C−H activation. Treatment of [(Cp*Ir)2(μ-dppm)(μ-H)2]2+ (2) with base (Et2NH) results in intramolecular C−H activation of the phenyl group in the dppm ligand to give [(Cp*Ir)(H){μ-PPh(C6H4)CH2PPh2}(μ-H)(Cp*Ir)]+ (6). The structures of 3, 5a, and 6 have been determined by X-ray diffraction methods.