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-9 H -fluorenes. Furthermore, the reaction can synthesize 4-acyl-9 H -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.