Visible-Light-Induced Oxyalkylation of 1,2,4-Triazine-3,5(2H, 4H)-diones with Ethers via Oxidative Cross-Dehydrogenative Coupling

An efficient and convenient method to synthesize 6-oxyalkylated 1,2,4-triazine-3,5(2 H, 4 H )-diones has been developed via visible-light-induced cross-dehydrogenative coupling reaction between 1,2,4-triazine-3,5(2 H, 4 H )-diones and ethers with a wide range of functional group tolerance. The present transformation employs the cheap and low-toxic 2- tert -butylanthraquinone as a metal-free photocatalyst and air as a green oxidant at room temperature. Moreover, this reaction can also be driven by sunlight as a clean energy resource. The synthetic utility of this method is further demonstrated by gram-scale reaction and application in the preparation of key intermediates of bioactive molecules.