Chemoselective Synthesis of N‐arylbenzamides and Benzoyloxyacetanilides from Aryl Isocyanides: Styrene as Aryl and Arylcarboxymethylene Source

Styrenes serve as unique aryl or arylcarboxymethylene source towards aryl isocyanides in the presence of Cu(II)/TBHP, and yield N‐arylbenzamides or benzoyloxyacetanilides respectively. The chemoselectivity of the reaction is controlled by the nature of the substituents present on styrene ring. Whereas styrenes substituted with electron‐releasing alkyl and alkoxy groups yield N‐arylbenzamides, unsubstituted styrene and those with electron‐withdrawing substituents furnish benzoyloxyacetanilides as the major product. With benzylamines as the substrate, N‐arylbenzamides are formed exclusively as they act only as an aryl donor. TBHP serves as a promoter and oxygen source. Both the pathways are believed to proceed through an initial oxidative C−C bond cleavage of styrene. magnified image