Preparation of aza-polycyclic aromatic compounds via superelectrophilic cyclizations

[GRPHICS] Alkenyl-substituted N-heterocycles react in superacidic CF3SO3H (triflic acid) to produce dicationic intermediates. These superelectrophiles undergo cyclizations to give varied aza-polycyclic aromatic compounds in generally good yields (27-99%, 16 examples). Theoretical calculations indicate a preference for charge-separated dicationic intermediates.