Synthesis of NHC-Iridium(III) Complexes Based on<i>N</i>-Iminoimidazolium Ylides and Their Use for the Amine Alkylation by Borrowing Hydrogen Catalysis

Anionic NHC ligands recently developed in our group, derived from N-iminoimidazolium ylides, were used to synthesize NHC-iridium(III) complexes. Their catalytic activities evaluated the amine alkylation of anilines using borrowing hydrogen catalysis. The high-yielding synthesis a small library complexes allowed rapid screening ideal steric bulk unit and basicity anionic tether for investigated model reaction. A bulky aromatic N group on imidazolidene moiety is required achieve high activity, latter proportional group. selected substrate scope reaction was performed, providing fair excellent yields desired alkylated anilines.