Cu-Catalyzed Cascade Reaction of Isoxazoles with Diaryliodonium Salts for the Synthesis of Acridines

A straightforward and efficient synthesis of acridine derivatives via a copper-catalyzed cascade reaction among isoxazoles and diaryliodonium salts is achieved. Various mono-, multi-substituted and 9-substituted acridine derivatives could be obtained in moderate to good yields. The process has gone through tandem double arylation and Friedel-Crafts reactions.