To achieve the goal of green chemistry and sustainable development, catalyst-free reactions and use of naturally abundant resources are gaining importance. In last two decades, C–H functionalization has gained attention for the synthesis of organic molecules. Here, we report a catalyst-free cross-dehydrogenative coupling reaction promoted by visible light for the synthesis of 1,3-oxazines. When α-aminoalkylnaphthols/phenols, commonly known as Betti bases, are irradiated with white light-emitting diode (LED, 23 W) in dimethyl sulfoxide (DMSO) solvent in an open reaction vessel at room temperature, cyclization takes place via α-C–H activation of tertiary amine moiety and forms a new C–O bond. Biologically important 1,3-oxazines are obtained in 58–85% yields. The various advantages of this methodology are (i) the reaction is catalyst-free, (ii) only aerial oxygen is needed as the oxidant, (iii) the reaction is visible light-promoted and (iv) a broad range of 1,3-oxazines are synthesized by varying the tertiary amine moiety or naphthols/phenols or the aryl substituent of the substrate Betti bases.

为了实现绿色化学和可持续发展的目标，无催化剂反应和利用天然丰富的资源变得越来越重要。在过去的二十年中，C-H 官能化在有机分子的合成中受到了关注。在这里，我们报告了一种由可见光促进的无催化剂交叉脱氢偶联反应，用于合成 1,3-恶嗪。当 α-氨基烷基萘酚/酚类（通常称为 Betti 碱）在室温下用二甲基亚砜 (DMSO) 溶剂中的白色发光二极管 (LED, 23 W) 照射时，通过 α-C 发生环化-H 活化叔胺部分并形成新的 C-O 键。生物学上重要的 1,3-恶嗪的产率为 58-85%。这种方法的各种优点是 (i) 反应无催化剂，