Facile Synthesis of Nitrogen-containing Polycyclic Aromatic Hydrocarbons from Perylene Bisimides

We have developed a facile procedure for the synthesis of pi-extended fluorubins from perylene bisimides. Iridium-catalyzed direct borylation, the Suzuki-Miyaura cross-coupling, and an acid-condensation sequence afforded pi-extended fluorubins 1 in moderate yields. X-ray diffraction analysis revealed a planar structure of 1. In addition, optical analysis and DFT calculations indicated the presence of intramolecular charge-transfer interactions in 1c.