Synthesis of Bis(phenanthropyrroles) via a Tandem Scholl Oxidation

Gońka, E.; Myśliwiec, D.; Lis, T.; Chmielewski, P. J.; Stępień, M.
J. Org. Chem. 2013, 78, 1260–1265 | view at publisher's site

An electron-rich 3,4-diarylpyrrole is shown to undergo a tandem inter- and intramolecular Scholl oxidation, providing access to bis(phenanthropyrroles), a new class of bipyrrole derivatives with extended pi-conjugation. Intermolecular coupling of two pyrrole molecues is found to be the initial step of this reaction. Bis(phenanthropyrroles) are characterized by restricted rotation around the alpha–alpha bond and exhibit strong blue fluorescence and large Stokes shifts.