Fig. 6: Four-fold arylation of acenes.
From: Birch reductive arylation by mechanochemical anionic activation of polycyclic aromatic compounds

a Four-fold arylation of anthracene for synthesis of tetrapyridinyldihydroanthracene 8. b Four-fold arylation of pentacene for synthesis of tetrapyridinyldihydropentacene 9. c Proposed reaction mechanism.