Proton Abstraction Monosubstitution of the Aryne

Based on this idea and looking for efficient transition metal-free procedures for the direct arylation of sp C—H bonds, several years later Daugulis et al. developed the intramolecular arylation of phenols with aryl halides involving the initial formation of a benzyne intermediate 

SCHEME 12.29 Arynes in transition metal-free arylation reactions. 

By using the fluoride-induced generation of arynes from o-(silyl)aryl triflates, Larock and Liu have developed the aryne-mediated A-arylation of amines, sulfonamides, and carbamates as well as the O-arylation of phenols and carboxylic acids. Remarkably, a wide variety of functional 

SCHEME 12.30 Aryne-mediated arylation of alkynes and (hetero)aromatics. 

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