Palladium-Catalyzed Direct Cyanation of Indoles with K4[Fe(CN)6]

Significance Direct cyanation of indole derivatives has been achieved with nontoxic K 4 [Fe(CN) 6 ] as cyanating agent. This selective cyanation is carried out with a palladium-catalyzed C-H bond activation using a Wacker-type regeneration of the catalyst.