Intramolecular direct arylation through mechanochemistry: efficient synthesis of corannulene-based peri-annulated curved nanographenes

Peri-annulation is recognized as an influential structural motif in accessing functional molecular materials. However, efficient synthetic access to peri-annulated structures remains challenging. Herein, we show that mechanochemistry is a valuable synthetic tool to achieve this goal. It is comparatively better than activation through microwave irradiation and conventional solution-phase reactions. The synthesized materials are molecularly curved nanographenes containing sulfur and selenium atoms. The curvature comes from the use of corannulene as the central building block, upon which the benzothiophene or benzoselenophene are peri-annulated through the palladium-catalyzed direct arylation reactions. Peri-annulation endows the nanographene structures with better optical properties as compared to other annulation chemistries.