Synthesis of 2-Cyanoanilides via Palladium-Catalyzed Reactions

Aromatic nitriles are omnipresent structural motifs found in pharmaceutical compounds, natural products, and functional materials [1]. Moreover, the nitrile group serves as an intermediate for a multitude of transformations into other principal functional groups such as carboxylic acids, amides, aldehydes, and ketones [2].Sandmeyer reaction and Rosenmund−von Braun reaction are traditional methods for the synthesis of benzonitriles. Aryl halides and aryl diazonium salts are used as the starting materials in the above mentioned reactions and equimolar amounts of heavy metal waste, arising from the use of stoichiometric amounts of CuCN as a cyanide source, is produced. Therefore, development of new methods using alternant cyanation agents is of considerable importance [3].In last decade, transition-metal-catalyzed cyanation of aryl halides has been introduced as a mild and direct route to this transformation and numerous reports have been published in this area [4]. All these reports suffer from prefunctionalization of starting material, especially brominaiton. Therefore, it was required to emerge a more attractive and simple method to synthesize aromatic nitriles. Recently, much attention has been paid to direct C–H functionalization reactions as the more efficient and greener methods. In this work, a palladium-catalyzed regioselective direct cyanation of acetanilides via palladium-catalyzed reactions is developed