Ligand-Free Cu-Catalyzed Cyanation of Aryl Halides with K4[Fe(CN)6] in Water

A simple methodology for Cu-catalyzed cyanation of aryl halides with K4[Fe(CN)6] was developed with water as the solvent in conjunction with ligand-free Cu(OAc)2·H2O as the catalyst. The suggested methodology is applicable to cyanation of a wide range of aryl iodides and activated aryl bromides, and allows the catalyst to be reused six times with a very slight change in the catalytic activity.