Visible-Light-Induced Radical Condensation Cyclization to Synthesize 3,4-Dihydropyrimidin-2-(1H)-ones/thiones Using Photoexcited Na(2) Eosin Y as a Direct Hydrogen Atom Transfer (HAT) Catalyst

[Image: see text] The data suggests that Na(2) eosin Y-derived photoinduced states act as a HAT catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones in ethanol at room temperature. This research establishes a novel function for using a nonmetallic natural dye, Na(2) eosin Y, available commercially and at a cheap cost in the photochemical synthesis using the least amount of catalyst, obtaining good results, speeding up the process, and achieving a high atom economy. The TON and TOF of 3,4-dihydropyrimidin-2-(1H)-ones/thiones are computed. Furthermore, this cycle runs on the gram scale as well, indicating the possibility of industrial purposes.