A Widely Applicable Dual-Catalytic System for Cross-Electrophile Coupling

A new dual catalytic system for cross-electrophile coupling reactions between aryl and alkyl halides that features a Ni catalyst, a Co co-catalyst, and a mild homogeneous reductant, is described. This is a unique combination of reagents for cross-electrophile coupling reactions, which results in one of the most versatile systems reported to date. For example, the coupling of aryl bromides and aryl iodides with alkyl bromides, alkyl iodides, alkyl mesylates, and benzyl chlorides is demonstrated under similar reaction conditions. The system is tolerant of numerous functional groups and is capable of coupling heteroaryl halides, di-ortho-substituted aryl halides, pharmaceutically relevant drug-like aryl halides, and a diverse range of alkyl halides. Additionally, the dual catalytic platform facilitates a series of novel one-pot three-component cross-electrophile coupling reactions of bromo(iodo)arenes with two distinct alkyl halides. Mechanistic studies indicate that the Ni catalyst activates the aryl halide electrophile, while the Co catalyst activates the alkyl electrophile.