Simple Strategy for Benzo[ g]chromene Synthesis via a Photochemical Intramolecular Cyclization Reaction

J Org Chem. 2023 Jul 7;88(13):8714-8721. doi: 10.1021/acs.joc.3c00598. Epub 2023 Jun 22.

Abstract

Photochemical reactions are often a desirable strategy for organic synthesis because they do not require toxic and expensive reagents and produce less waste than thermal reactions. Herein, a facile photochemical strategy is described to synthesize benzo[g]chromene derivatives. This strategy utilizes the photoredox reaction of quinones, which allows C-H bond oxidation in the vicinity of the photoexcited quinone carbonyl group. The reaction mechanism was investigated using 1H NMR analysis. The intramolecular cyclization reaction proceeded via the formation of 1,3-dioxole compounds as intermediates by the photoredox reaction of p-quinone, followed by re-cyclization. The synthesized benzo[g]chromene derivatives are important heterocyclic skeletons with useful biological and pharmacological properties.

MeSH terms

  • Benzopyrans* / chemistry
  • Benzoquinones*
  • Cyclization
  • Quinones / chemistry

Substances

  • Benzopyrans
  • quinone
  • Benzoquinones
  • Quinones