Solvent promoted reversible cyclometalation in a tethered NHC iridium complex

摘要

Reaction of [lr(COD)(py-l~tBu)]+ (py-l~tBu = 3-tert-butyl-1-picolyl-imidazol-2-ylidene) with acetonitrile results in reversible intramolecular C-H bond activation of the NHC ligand and formation of [Ir(η~2:η~1-C_8H_(13))(py-l~tBu')(NCMe)]~+. Coordinated COD acts as an internal hydride acceptor and acetonitrile coordination offsets the otherwise unfavourable thermodynamics of the process.