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.