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

Photochemical reactions are often a desirable strategyfor organicsynthesis because they do not require toxic and expensive reagentsand produce less waste than thermal reactions. Herein, a facile photochemicalstrategy is described to synthesize benzo[g]chromenederivatives. This strategy utilizes the photoredox reaction of quinones,which allows C-H bond oxidation in the vicinity of the photoexcitedquinone carbonyl group. The reaction mechanism was investigated using H-1 NMR analysis. The intramolecular cyclization reaction proceededvia the formation of 1,3-dioxole compounds as intermediates by thephotoredox reaction of p-quinone, followed by re-cyclization.The synthesized benzo[g]chromene derivatives areimportant heterocyclic skeletons with useful biological and pharmacologicalproperties.

Automated summary

A facile photochemical strategy utilizing the photoredox reaction of quinones for C-H bond oxidation was developed to synthesize benzo[g]chromene derivatives. The intramolecular cyclization reaction proceeded via the formation of 1,3-dioxole compounds as intermediates. The synthesized derivatives possess important heterocyclic skeletons with useful biological and pharmacological properties.