Copper-Catalyzed Oxidative Ring Closure of ortho-Cyanoanilides with Hypervalent Iodonium Salts: Arylation-Ring Closure Approach to Iminobenzoxazines

A novel, highly modular synthetic methodology with high functional group tolerance was developed for the construction of iminobenzoxazine derivatives from ortho-cyanoanilides and diaryliodonium triflates via an oxidative arylation-cyclization path. The reaction is supposed to involve the formation of highly active aryl-copper(III) species. In this novel transformation, copper(II) triflate was used as catalyst in 1,2-dichloroethane or ethyl acetate and the reaction takes place at 75 degrees C in 2-16 h.