Visible-Light-Induced C–H Alkylation of 1,2,4-Triazine-3,5(2<i>H</i>,4<i>H</i>)-diones via Infrequent 1,2-Hydrogen-Atom Transfer
Mi Wang, Yangyang Wang, Jie Wang, Yafei Zhu, Penghua Zhang, Cuimei Zhang, Jian Chen, Li Guo, Guanghui Lv, Yong Wu
Abstract
1,2,4-Triazine-3,5(2 H,4 H) -diones are widely present in various drug molecules and bioactive molecules. A visible-light-driven C–H alkylation of 1,2,4-triazine-3,5(2 H,4 H )-diones via 1,2-hydrogen-atom transfer (1,2-HAT) of amide radicals is first reported, providing an environmentally friendly and sustainable pathway to enrich the structural and functional diversity of 1,2,4-triazine-3,5(2 H,4 H )-diones. This novel protocol is characterized by mild and metal-free reaction conditions, an operationally simple method, and good functional group tolerance. To our delight, other heterocycles, such as isoquinoline and coumarin, also undergo alkylation reactions to construct C(sp 2 )-C(sp 3 ) bonds via infrequent 1,2-HAT under current conditions.