Phototriggered Self-Catalyzed Phosphorylation of 3,4-Dihydroquinoxalin-2(1 H )-ones with Diarylphosphine Oxides in EtOH.

A highly effective external photocatalyst- and additive-free method for the phosphorylation of 3,4-dihydroquinoxalin-2(1 H )-ones to produce phosphorylated dihydroquinoxalin-2(1 H )-ones has been reported. A wide variety of phosphorylated products were formed in good to excellent yields. Preliminary mechanistic studies reveal that the phosphorylation process involves an EnT process, a SET process, a HAT process, and a deprotonation process.