General and Mild Nickel-Catalyzed Cyanation of Aryl/Heteroaryl Chlorides with Zn(CN)2: Key Roles of DMAP

A new and general nickel-catalyzed cyanation of hetero(aryl) Chlorides using less toxic Zn(CN)(2) as the cyanide source has been developed. The reaction relies on the use of inexpensive NiCl2.6H(2)O/dppf/Zn, as the catalytic system, and DMAP as the additive, allowing the cyanation to occur :under mild reaction conditions (50-80 degrees C) with wide functional group tolerance. DMAP was found to be crucial for successful transformation, and the reaction likely proceeds via a Ni(0)/Ni(II) catalysis based on mechanistic studies. The method was also successfully extended to aryl bromides and aryl iodides.