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 CuI complexes based on benzotriazoles were synthesized and their crystal structures were determined by X-ray powder diffraction analysis.