Homocoupling of Aryl Halides Using Nickel(II) Complex and Zinc in the Presence of Et4NI. An Efficient Method for the Synthesis of Biaryls and Bipyridines

Reduction of NiX2(PPh3)2 with zinc in the presence of Et4NI gives a nickel catalyst which has been proven to be useful for the coupling of aryl halides. This nickel catalyst can be prepared in THF without an additional triphenylphosphine and is effective for the homocoupling of aryl chlorides, bromides, and iodides to produce biaryls and bipyridines in good yields. The reported new approach provides a simple access to novel derivatives of biaryls and bipyridines.