Synthesis of Aromatic Nitriles Using Nonmetallic Cyano-Group Sources

Aromatic nitriles are prepared efficiently through transition-metal- mediated cyanation of aryl (pseudo)halides with metallic cyano-group sources, such as CuCN, KCN, NaCN, Zn(CN)2, TMSCN, or K4[Fe(CN) 6]. However, this approach often suffers from drawbacks, such as the formation of stoichiometric amounts of metal waste, the poisoning of the metal catalysts, or the generation of toxic HCN gas. As a result, a range of nonmetallic organic cyano-group sources have been explored for the cyanation of aryl halides and arene C-H bonds. This Minireview summarizes types of nonmetallic cyano-group sources and their applications in the preparation of aryl nitriles. Introducing CN: Recently, a range of nonmetallic organic cyano-group precursors (see scheme) have been developed as attractive alternatives to metal cyanides that have been frequently employed in the catalytic cyanation of aryl halides. This Minireview summarizes the development of organic cyano-group precursors and their application in the cyanation of aryl halides, boronates, boronic acids, arene carboxylic acids, and (hetero)arene C-H bonds. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.