Iron-Catalyzed Reductive Cross-Coupling of Heteroaryl Iodides with Alkyl Iodides.

Abstract

The coupling reaction of highly reactive heteroaryl iodides and alkyl iodides remains a longstanding challenge because of competing side reactions, including dehalogenation, hydrogenation, homocoupling, and radical dimerization. Here, we report an iron-catalyzed reductive cross-coupling of heteroaryl iodides with alkyl iodides enabled by a hydrosilane-based reducing system. This strategy provides efficient access to C(sp2)-C(sp3) bonds and exhibits a broad substrate scope, good functional group tolerance, gram-scale scalability, and applicability to the late-stage functionalization of complex bioactive molecules. Mechanistic studies support the involvement of alkyl radical intermediates and low-valent iron species, with an iron(0) complex proposed as a catalytically relevant intermediate.