Visible-Light-Induced Metal- and Photosensitizer-Free C(sp³)–H Phosphorylation of 3,4-Dihydroquinoxalin-2(1H)-ones with Diphenylphosphine Oxide

Herein, we report a direct phosphorylation of the C(sp3)–H bond of 3,4-dihydroquinoxalin-2(1H)-ones using oxygen as a green oxidant under visible light at room temperature. This transformation was readily accomplished in the absence of metal and photosensitizer to construct new C(sp3)–P bonds and provide a series of phosphonylated dihydroquinoxalin-2-ones in good to excellent yields. This approach opens straightforward and environmentally friendly access to 3-phosphoryl quinoxalin-2-ones derivatives.