A chelation-assisted palladium-catalyzed cascade bromination/cyanation reaction of 2-arylpyridine and 1-arylpyrazole C−H bonds has been developed. Notably, the reaction employs K3[Fe(CN)6] as a safe and nontoxic cyanide source, providing aromatic nitriles in moderate to good yields in one-pot. The procedure tolerates methoxy, chloro, fluoro, cyano, trifluoromethyl, and carbomethoxy groups.