Functionalization of the "Bay Region" of Perylene in Reaction with 1-Arylalk-2-yn-1-ones Catalyzed by Trifluoromethanesulfonic Acid: One-Step Approach to 1-Acyl-2-alkylbenzo[ghi]perylenes

We describe a convenient method of the synthesis of 1-acyl-2-alkylbenzo[ghi]perylenes via functionalization of the “bay region” of perylene in the reaction with 1-arylalk-2-yn-1-ones catalyzed by trifluoromethanesulfonic acid. We showed that the formation of 1-acyl-2-alkylbenzo[ghi]perylenes from perylene and 1-arylalk-2-yn-1-ones might occur via spontaneous aromatization of 1-acyl-2-alkyl-2a,12a-dihydrogenbenzo[ghi]perylenes by oxidation with dioxygen or by the hydrogen transfer to 1-arylalk-2-yn-1-ones. These compounds are fluorescent in solution with a high Stokes shift and with a ΦF value of up to 0.17 (and 0.36 in solid).