Non-toxic K4 [Fe (CN) 6] was demonstrated to be effective as a green cyanating agent for the cyanation of alkyl halides using PPh3/Pd (OAc) 2 as a catalyst system. The presented method allowed a series of benzyl chlorides to be smoothly cyanated in up to 88% yield. In order to avoid or suppress the deactivation of the catalyst, the reaction was required to be performed in a stringent inert ambiance.
[Velcicky, Juraj; Soicke, Arne; Steiner, Roland; Schmalz, Hans-Guenther Journal of the American Chemical Society, 2011 , vol. 133, # 18 p. 6948 - 6951]