Visible Light‐Triggered Radical Annulation of ortho‐Thioaryl Ynones: A General Approach to Prepare 3‐Sulfenylthiochromones

Abstract

AbstractA visible light‐mediated protocol was developed for the construction of 3‐sulfenylthiochromenones by a radical annulation of ortho‐thioaryl ynones. The reaction is triggered by a sulfur‐centered radical, which is formed through the light excitation of an intramolecular electron donor‐acceptor complex (EDA‐complex). A total of twenty‐one compounds were prepared, in poor to excellent yields (28–98 %), sixteen of which are unprecedented. The reactions were conducted under open‐air conditions, not requiring metal catalysts, oxidant species, or heating, making this a mild and environmentally friendly approach to access valuable compounds.