Sequential Nitrene Transfers to an Organometallic Half-Sandwich Iridium Complex

Nitrene transfer to an iridium(Cp*) complex with a pyridyl-amide bidentate ligand drives an unexpected outer-sphere C–H activation and amide functionalization reaction mediated by this metal center. This is a significant departure from C–N bond-forming processes in mononuclear rhodium and iridium catalysts, which require C–H activation at the metal center prior to nitrene transfer and insertion (an inner-sphere C–H insertion pathway). The mechanism likely involves a high oxidation state iridium-imido reactive species capable of hydrogen atom abstraction and a radical-based rearrangement during the formation of the ultimate iridium product.