Preparation of Aza-Polycyclic Aromatic Compounds via Superelectrophilic Cyclizations

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.