Intermolecular Metal-Catalyzed Direct Arylation of Arenes

Intermolecular Metal-Catalyzed [Direct Arylation of Arenes 

3 Intermolecular Metal-Catalyzed Direct Aiylation of Arenes I 373 

A palladium-catalyzed methylation of 2-arylpyridines with tibutylperoxyde, and related peroxides, was recently developed [47]. This transformation also involves a C—H bond-activation step by a Pd(II)R complex, although no isotope effect was observed in an intramolecular competition experiment, which suggests that a radical mechanism might be involved. 

The direct arylation of aromatic C—H bonds takes place with [Cp IrHCl]2 complexes as catalysts in the presence of KOt-Bu [48]. The regjoselectivity observed in 

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