Understanding the steric demand of the reactions of nickel(0) complexes with aryl halide substrates
Year: 2026
Type: preprint
Abstract: Nickel complexes are able to undergo reactions with organohalides by a variety of fundamental steps, which can be either one-electron or two-electron in nature. Two electron processes are typically some flavour of oxidative addition (OA), but various mechanisms have been proposed for the one-electron reactions, including inner-sphere halogen atom abstraction (HAA) and outer-sphere single electron transfer (SET). It was recently proposed that the steric bulk of a substrate can be used as an indicator of whether HAA is feasible, and therefore that SET was in operation for a specific and bulky substrate. However, the steric requirements for HAA by nickel have not yet been systematically assessed. Here we report a structured assessment of how HAA feasibility might vary with ligand and substrate steric impact. We find that HAA by [Ni(PMe 3 ) 3 ] is feasible even for sterically very hindered substrates. Systems with ferrocene-derived bisphosphine ligands tend to prefer HAA when the ligand and/or the substrate are very sterically bulky.
Source: ChemRxiv
Institution: University of Strathclyde
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Funder: Leverhulme Trust
OpenAlex ID: W7214674355