Synthesis of bis(phenanthropyrroles) via a tandem Scholl oxidation

J Org Chem. 2013 Feb 1;78(3):1260-5. doi: 10.1021/jo302486x. Epub 2013 Jan 18.

Abstract

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 π 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 α-α bond and exhibit strong blue fluorescence and large Stokes shifts.