Cross-Coupling of Aryl Iodides with Malononitrile Catalyzed by Palladium N-Heterocyclic Carbene Complex System

Eight N heterocyclic carbenes (NHC), generated in situ from their imidazolium salts, as ligands of palladium complexes were used for the catalytic coupling of iodobenzene with malononitrile anion. It was found that 1,3 bis(2,4,6 trimethylphenyl) imidazolium chloride (IMesHCl) Pd 2(dba) 3 catalytic system has the highest activity to obtain phenyl malononitrile among the imidazolium salts. The substituted iodoarenes reacted with malononitrile anions by using the catalytic system to give cross coupling products in yields from 50% to 96%.