Aryl Diazonium Salts: Powerful Arylating Agents for Catellani-Type <i>ortho</i>-Arylation

The Catellani reaction provides an efficient synthetic approach to polyfunctionalized arenes. However, the selective ortho-arylating reagents employed in these reactions have been strictly limited to activated bromoarenes. As demonstrated in this work, aryl diazonium salts bearing both electron-donating and electron-withdrawing substituents, after in situ transformations with KI into the corresponding iodoarenes, were efficient arylating reagents for Catellani type ortho-arylation approaches.