Pyrazole-directed, fluoroalcohol-free arylation of C-H bonds

Directed arylation of sp2 C−H bonds is often considered one of the most convenient methods to rapidly increase the complexity of organic molecules. However, most of the available methods utilized fluoroalcohols such as hexafluoroisopropanol (HFIP) as the solvent. Herein we report a simple method for palladium-catalyzed, directed arylation of arene C−H bond using acetic acid solvent. The successful functionalization relies on the use of pyrazole directing group.