Metal-catalyzed cyanation of aromatic hydrocarbon with less toxic nitriles as a cyano source

Abstract less toxic and inexpensive organic nitriles as cyano sources for the cyanation of various substituted aromatic hydrocarbons such as aryl halides, aryl boronic acids, aryl carboxylic acids, indoles, diazoarenes, aryl alkynes, aryl sulfonamides and directing groups substituted arenes were reviewed. Lately, much process is made in realizing the possibility of less toxic cyanide sources such as as organic nitriles (MeCN, DMF, MeNO2, DMSO, TsCN, BrCN, ArOCN, AMBN, AlBN, ArCH2CN) for the cyanation and these CN sources when used as a slow dosage cyanide source could solve the problem of using metal cyanides (K4[Fe(CN)6], Zn(CN)2, KCN, CuCN, NaCN) that cause rapid deactivaction of catalyst. To provide solution for these problems, we discussed new Pd, Cu, Ru, Rh, and Ni catalyzed systems to achieve the cyanation with slow-release cyanide sources. Thus, the focus of the review is to highlight and make known the problems associated with metal catalysts and cyano sources.