An N-heterocyclic carbene-based nickel catalyst for the Kumada–Tamao–Corriu coupling of aryl bromides and tertiary alkyl Grignard reagents.

In this study, nickel-catalyzed coupling reactions between arylhalides and tert -alkyl Grignard reagents were developed. Our original bicyclic NHC ligands reduced the formation of isomerized products, and we found that NMP as a co-solvent suppressed the reduction process. Under the optimal conditions we developed, the catalyst loading was lowered to 0.5 mol %, and catalyst loading using ortho -substituted aryl bromides was also applicable at the level of 2.0 mol %. [ABSTRACT FROM AUTHOR]