Regioselective N1- or N2-modification of benzotriazoles with iodonium salts in the presence of copper compounds

Modification of benzotriazoles with iodonium salts [diphenyl- and (E)-styrylphenyliodonium tosylates] occurs at the N¹-position in the presence of K₂CO₃ as a base and CuI as a catalyst in CH₂Cl₂, whereas in the presence of stoichiometric amount of [Cu₂(TMEDA)₂(OH)₂]Cl₂ complex regioselective N²-modification proceeds. Two new Cu^I complexes based on benzotriazoles were synthesized and their crystal structures were determined by X-ray powder diffraction analysis.