Visible-Light-Induced Direct Methylation of Quinoxalin-2(1 H )-ones with N , N , N ′, N ″, N ″-Pentamethyldiethylenetriamine as the Methyl Source

Herein, a facile visible-light-driven methylation of quinoxalin-2(1 H )-ones with N, N, N ′, N ″, N ″-pentamethyldiethylenetriamine as a methyl source was reported. This protocol features broad compatibility and scalability. The transformation was driven by direct irradiation with visible light, requiring no external photocatalyst. Mechanistic investigations reveal an oxygen-triggered radical pathway, excluding EDA complex or PET processes. A practical route to 3-methylquinoxalin-2(1 H )-ones was thus established.