Schnitzlein, MatthiasMatthiasSchnitzleinMutzel, CarinaCarinaMutzelShoyama, KazutakaKazutakaShoyamaJEFFREY M. FARRELLWurthner, FrankFrankWurthner2022-05-272022-05-272022https://www.scopus.com/inward/record.uri?eid=2-s2.0-85121426674&doi=10.1002%2fejoc.202101273&partnerID=40&md5=b933ff864b8d76765c843bf24b9b938ehttps://scholars.lib.ntu.edu.tw/handle/123456789/612089Utilizing Pd-catalyzed [5+2] annulation a series of heptagon-extended corannulenes could be synthesized from a borinic acid precursor furnished by C?H borylation strategy. Single-crystal X-ray analysis revealed the presence of two conformational enantiomers crystallizing in a racemic mixture. Through their embedded five- and seven-membered rings these polycyclic aromatic hydrocarbons (PAHs) exhibit both negative and positive curvature and UV/Vis/NIR absorption spectroscopy as well as cyclic voltammetry experiments provided insights into the influence of larger flanking aromatic systems and electron-donating substituents encompassing the heptagonal ring. Through [5+2] annulation of acenaphthylene an azulene-containing PAH with intriguing optoelectronical properties including a very small bandgap and absorption over the whole visible spectrum could be obtained. Theoretical calculations were employed to elucidate the long-wavelength absorption and aromaticity. ? 2021 The Authors. European Journal of Organic Chemistry published by Wiley-VCH GmbHjournal article10.1002/ejoc.2021012732-s2.0-85121426674