“Masked” areneboronic acids have been prepared by Ir-catalyzed C–H borylation of arenes. A [Ir (OMe)(cod)] 2 complex with a DPPE ligand showed the highest catalytic activity in the C– H borylation of benzene at 80° C. The reaction system can be applied to substituted arenes, including halogen-substituted arenes. 1, 3-Dihalobenzenes undergo the C–H borylation at their 5-positions in a regioselective fashion, affording 3, 5-dihaloareneboronic acid ...