Iron-Mediated Inter- and Intramolecular Reductive Cross-Coupling of Unactivated Alkyl Chlorides with Aryl Bromides.

An efficient one-pot intermolecular reductive cross-coupling of unactivated primary and secondary alkyl chlorides bearing β-hydrogens with aryl bromides is described. A combination of magnesium turnings and a catalytic amount of the commercially available iron(III) complex Fe(PPh3)2Cl3 was used, and the conditions were also successfully extended to an intramolecular reaction for the first time. Both types of cross-coupling reactions proceed under mild conditions, involving the in situ generation of aryl Grignard reagents, and show good applicability to a variety of readily available unactivated alkyl chlorides, which have previously been challenging substrates in iron-catalyzed reductive cross-coupling reactions.