Translation of Nickel-Catalyzed C(sp)-C(sp) Cross-Electrophile Coupling to Non-Amide Solvents.

The cross-electrophile coupling of organobromides is widely utilized in organic synthesis but generally requires undesirable amide solvents (e.g., DMF, DMA, and NMP). We report that the combination of a strongly donating, bidentate nitrogen ligand, LiI, and 4-picoline enables coupling in a variety of alcohol, ester, and ethereal solvents at up to 50 g scale. An improved synthesis of the optimal ligand, 4,4'-bis(dimethylamino)-2,2'-bipyridine, is also reported on the basis of the reductive homocoupling of 4-dimethylamino-2-chloropyridine.