Facile and reversible O-H and C-H activation by a chiral Iridium(I) complex

The reactivity of the dinuclear Ir(I) complexes cis- and trans-[Ir-2(mu-Cl)(2)((R)-(S)-PPFPPh2)(2)] (1, (R)-(S)-PPFPPh2 = (R)-1-C(S)-2-(diphenylphosphino)ferrocenyl)ethyldiphenylphospihine) toward O-H and C-H bonds has been studied (1 was previously shown to be a catalyst precursor for the asymmetric addition of aniline to norbornene, via N-H activation). Compound 1 undergoes clean oxidative addition of water in toluene, affording a mixture of two isomeric, dinuclear hydroxo-bridged Ir(III) complexes. Isomerization to a single product, syn-trans-[((R)-(S)-PPFPPh2)(2)Ir2Cl2(H)(2)(mu-OH2] (3), takes place upon dissolution in THF. syn-trans-3 has been characterized by X-ray diffraction. Reaction of 1 with 2,6-dimethylaniline affords the corresponding sp(3) C-H activation product 5, the crystal structure of which has been determined. Both oxidative addition reactions are (partly) reversible at high temperature.