Scheme 27.

Intramolecular oxidative coupling of pyrrolo[3,2‐b]pyrroles. Reagents and conditions: a) FeCl3 (20 equiv), CH2Cl2, CH3NO2, RT.

Intramolecular oxidative coupling of pyrrolo[3,2‐b]pyrroles. Reagents and conditions: a) FeCl3 (20 equiv), CH2Cl2, CH3NO2, RT.