Nickel-Catalyzed Reductive Cross-Coupling of Heteroaryl Chlorides and Aryl Chlorides

We report a nickel-catalyzed cross-electrophile coupling reaction of aryl chlorides and heteroaryl chlorides enabled by a synergistic combination consisting of halide effects and the addition of a magnesium salt. The reaction relies on the electronic difference between the aromatic and heteroaromatic coupling partners to afford the cross-coupled biaryl products using a single catalyst. A variety of heterocycles were amenable to the reaction, as well as a wide range of aryl chlorides, with electron-deficient aryl chlorides performing the best in the reaction. Preliminary mechanistic evidence demonstrates the MgCl2 is essential to the reaction by accelerating the reduction of Ni(II), and that small quantities of iodide lead to improved yields.