Palladium(II)-Catalyzed Direct Conversion of Methyl Arenes into Aromatic Nitriles

摘要

The nitrile group is a prevalent functional group in organic synthesis and can be easily used for functional group transformations, including the formation of amines, amides, acids, aldehydes, and heterocycles.111 In particular, aromatic nitriles have found wide application in the synthesis of natural products, materials, pharmaceuticals, agricultural chemicals, and dyes. However, the methods to introduce a cyano group onto an aromatic ring are still limited. The Sandmeyer reaction and the Rosenmund-von Braun reaction are the traditional methods for the synthesis of aromatic nitriles. However, in both cases, highly toxic copper(I) cyanide is used as the cyanating agent. More recently, transition-metal-catalyzed cyanation of aromatic halides has emerged as an attractive method to access aromatic nitriles. In particular, aromatic cyanation using non-metallic cyano-group sources has attracted great attention. The dehydration of aryl amides or oximes, and the oxidative dehydration of benzylic amines or alcohols with ammonia are alternative approaches toward aromatic nitriles.