With nitrogen nucleophiles, such as aniline, the ring opening afforded 11 in 84% yield. A common additional copper-catalyzed ring closure to phenoxazine derivates could not be conducted under literature known conditions. Copper-catalyzed treatment with mesitylamide yielded pure phenoxazine 12 in 84%. Additional bifunctionalizations were achieved by a sulfur-iodine exchange or by a palladiumcatalyzed carbon-carbon coupling to obtain phenoxathiine 13 in 85% yield and dibenzofuran 14 in 90% yield. Finally, the novel iodazinium triflates were also derivatized with similar procedures (Scheme 5). A copper(I)iodide-mediated ring opening of 2a yielded the diiododiphenylamine 15a in a low yield of 14%. A change of the sulfonamide from Ntosyl to N-mesyl yielded the desired product 15b in a good yield of 77%. The coppercatalyzed ring opening of 2a with acetate furnished monofunctionalized 16 in 94% yield. While the yield for the derivatization with aniline significantly dropped compared to the oxygen derivative, the o-diphenylamine 17 could still be obtained in 56% yield.