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

Abstract

AbstractTribenzotriquinacene (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.