Dicationic oligotelluroxane or mononuclear telluronium cation? Elucidation of the true catalytic species and activation mechanism of the benzylic carbon-halogen bond.

The application of diaryltelluronium cations as chalcogen bonding organocatalysts was investigated for the Ritter-like reaction using time-course NMR analysis. The resistance to water of dicationic oligotelluroxanes differed depending on the oligomer chain length and counter anions. The activation mechanism of the substrate was discussed based on DFT calculations.