Luminescent Chiral Furanol-PAHs via Straightforward Ni-Catalysed Csp2-F Functionalization: Mechanistic Insights into the Scholl Reaction

Here we report the stepwise synthesis of new nanographenes (NGs) and polycyclic aromatic hydrocarbons (PAHs) obtained via Scholl ring fusion applied at aromatic homologation compounds, which are obtained through one-step Ni-catalysed Csp2-F functionalization. The latter are rapidly accessed valid precursors for the Scholl reaction, and screening of experimental conditions allowed us to describe for the first time furanol-bearing PAHs. Mechanistic insights are obtained by DFT to rationalize the formation of the furanol PAHs under moderately acidic conditions. All PAHs and NGs synthesized show moderate/weak fluorescent properties, and all PAHs crystallized show some degree of curvature and are obtained as racemic mixtures. Enantiomeric separation by chiral HPLC of one furanol-bearing PAH allowed the study of their chiroptical CD properties.

Automated summary

In this study, a stepwise synthesis of new nanographenes and polycyclic aromatic hydrocarbons (PAHs) via Scholl ring fusion is reported. The aromatic homologation compounds, obtained through one-step Ni-catalysed Csp2-F functionalization, are shown to be valid precursors for the Scholl reaction. Furanol-bearing PAHs are described for the first time by screening experimental conditions. DFT calculations provide mechanistic insights into the formation of furanol PAHs under moderately acidic conditions. All synthesized PAHs and nanographenes exhibit moderate/weak fluorescent properties, and the crystallized PAHs show some degree of curvature and are obtained as racemic mixtures. Enantiomeric separation of one furanol-bearing PAH allows for the study of its chiroptical CD properties.