Steric effects determine the mechanisms of reactions between bis(N-heterocyclic carbene)-nickel(0) complexes and aryl halides

Abstract

Computational investigations of the reactions of [Ni(NHC)₂] complexes with aryl halides show that the outcomes are governed by the steric impact of the ligand (NHC = N-heterocyclic carbene). Small ligands permit facile oxidative addition, leading to Ni^II complexes, while larger NHC ligands prevent coordination of the aryl halide and favour the halide abstraction to form Ni^I.