Iridium(I) Complexes with Anionic N-Heterocyclic Carbene Ligands as Catalysts for H/D Exchange in Nonpolar Media

A series of neutral iridium(I) complexes of the general type [(WCA-NHC)]IrL(COD)] (COD=1,5-cyclooctadiene; L=phosphine, pyridine), bearing anionic N-heterocyclic carbenes (WCA-NHC) with a weakly coordinating anionic (WCA) borate moiety, were prepared by addition of phosphines and pyridine to [(WCA-NHC)]Ir(COD)], in which the available coordination site is stabilized by intramolecular metal-arene interaction (pi-face donation). The solvent and substrate scope of the neutral complexes as catalysts for H/D exchange was investigated, revealing their suitability for promoting efficient deuteration in nonpolar solvents such as cyclohexane.