Bilateral aromatic extension of corannulene nucleus

Abstract

Herein we show that a dibromo imide derivative of corannulene could be subjected to a palladium-catalyzed Heck reaction in order to install aryl vinylene groups in a bilateral fashion on the C5-symmetric aromatic nucleus. A photochemically-induced oxidative cyclization then affords π-extended structures in isolated overall yields of 35–44 %. Due to the aromatic area extension and the presence of electron withdrawing groups, the synthesized molecules exhibit an anodic shift of ≈1 V in their first reduction potential as compared to pristine corannulene. The bilateral growth of the aromatic scaffold, therefore, represents a viable strategy to prepare π-extended corannulenes with an electron deficient character.