Merging Tribenzotriquinacene and Triptycene

The geometric and chemically related structural motifs of tribenzotriquinacene (TBTQ, 1) and triptycene (2) have been merged for the first time on the level of the parent hydrocarbons. A classical cyclodehydration strategy was used to synthesize 1,4-dimethoxytribenzotriquinacene 13 and convert it into the corresponding TBTQ-based para-benzoquinone 4. The Diels–Alder reaction of 4 with anthracene afforded anti- and syn-cycloadducts 22 and 23, respectively, in the ratio of 1:3, which were transformed into dibenzo(triptyceno)triquinacene 5, a new parent polycyclic aromatic hydrocarbon, and derivatives 25–28. The structure of TBTQ-quinone 4 was also extended to give related 1,4-anthraquinone 32. The intriguing geometrical and structural aspects of the merged TBTQ-triptycene motif were examined by X-ray crystal analysis and molecular modeling with the aim to construct tris(triptyceno)triquinacenes, hypothetical analogues that are characterized by a deep molecular cavity.