Iron−Phosphine, −Phosphite, −Arsine, and −Carbene Catalysts for the Coupling of Primary and Secondary Alkyl Halides with Aryl Grignard Reagents

Abstract

Simple catalysts formed in situ from iron chloride and a wide range of monodentate and bidentate phosphines and arsines have been screened in the coupling of alkyl halides bearing beta-hydrogens with aryl Grignard reagents. The best of these show excellent activity, as do catalysts formed in situ with monodentate trialkyl and triaryl phosphite ligands. N-heterocyclic carbene-based precatalysts, either preformed or made in situ, also show excellent performance.