Visible Light-Mediated Synthesis of Chalcogen-Decorated 2,3-Dihydrobenzofurans in the Absence of Photocatalyst and Oxidants

A sustainable visible light-promoted protocol for preparing selenium- and sulfur-decorated 2,3-dihydrobenzofurans from 2-allylphenols and diorganyl dichalcogenides is reported. The reaction proceeds under blue LEDs irradiation (Kessil PR160L, λ_max = 440 nm) under mild conditions, in the absence of photocatalysts or oxidants, in accordance with the green chemistry principles. Eighteen derivatives were obtained, covering electron-rich, electron-deficient, and polycyclic systems, with yields from 20% to 96%. The method is operationally simple, scalable, and tolerant to diverse aryl substituents, although the presence of electron-withdrawing groups reduces its efficiency. This approach offers an ecofriendly alternative to conventional oxidative or photocatalyst-mediated strategies to prepare the target molecules, opening new opportunities for advancing organoselenium chemistry and exploring its potential in organic synthesis.