Synthesis and properties of thienonaphtho[bc]pyridines and thienonaphtho[bc]quinolines†

The incorporation of heteroatoms within polycyclic aromatic compounds has gained significant interest due to its potential to effectively alter the inherent physicochemical properties of compounds without the need for profound structural changes. We herein report the development of a modular synthesis of hitherto unknown thienonaphtho[bc]pyridines and thienonaphtho[bc]quinolines in very good yields by Brønsted acid mediated cycloisomerization, permitting selective access to two isomeric products that are isoelectronic to the parent dibenzopyrene. The photophysical and electrochemical properties of the desired compounds were extensively studied and further complemented by DFT calculations.