Trifunctionalization of Aryl Iodides Involving Three C–H Activations via Palladium/Norbornene Catalysis

Herein, we report a palladium/norbornene-catalyzed trifunctionalization of ortho-unsubstituted aryl iodides involving three C-H activations. This transformation employs anhydrides and benzyl bromides as different electrophiles to achieve ortho-C-H benzylation and acylation followed by intramolecular ipso-arylation, thus constructing 4-acyl-9H-fluorenes. Furthermore, the reaction can synthesize 4-acyl-9H-fluorenones via double ortho-C-H acylation and subsequent cyclization under benzyl bromide-free conditions. This protocol demonstrates excellent chemo- and regioselectivity, along with broad substrate scope.