A Paternò-Büchi Reaction of Aromatics with Quinones under Visible Light Irradiation.

Reported herein is a Paternò-Büchi reaction of aromatic double bonds with quinones under visible light irradiation. The reactions of aromatics with quinones exposed to blue LED irradiation yielded oxetanes at -78 °C, which was attributed to both the activation of double bonds in aromatics and the stabilization of oxetanes by thiadiazole, oxadiazole, or selenadiazole groups. The addition of Cu(OTf) to the reaction system at room temperature resulted in the formation of diaryl ethers via the copper-catalyzed ring opening of oxetanes in situ. Notably, the substrate scope was extended to general aromatics.