Exploring the "fold-in" strategy toward the construction of a highly-strained triazasumanene skeleton.

The synthesis of tribenzotriazasumanene was attempted on the basis of the "fold-in" synthesis of cyclic pyrrole trimer 5 and its analogues under oxidative and reductive conditions. While unexpectedly triply-fused product 6 was obtained in the oxidation of 5 with FeCl3 and AgOTf, the reductive coupling of hexabromo-tri-N-methylpyrrole trimer 9 furnished partially fused product 10. These results indicate the potential of the "fold-in" strategy that gave complementary outcomes depending on the reaction conditions.