Switching the Statistical C3/C1 Ratio in the Threefold Aromatic Substitution of Tribenzotriquinacenes towards the C3 Isomer

Tribenzotriquinacene (TBTQ) is a bowl‐shaped molecule that has been widely used as a molecular building block in supramolecular and materials chemistry. Especially C₃‐symmetric threefold‐substituted TBTQs are interesting for these purposes. Until now a general and selective synthetic approach to those C₃‐symmetric products was lacking, mainly because the typically used electrophilic aromatic substitution reactions of the parent TBTQ hydrocarbons produce predominantly the C₁ isomer over the C₃ isomer (3:1 statistical ratio). Herein we introduce a threefold borylation of TBTQ with the C₃ isomer as the main product (2.6:1 C₃/C₁ ratio). The borylated TBTQ can be converted in good yields into other C₃‐symmetric TBTQs, thus allowing straightforward synthetic access to new building blocks for supramolecular and materials chemistry.