By utilizing an underexplored reaction mode of C,N-cyclic azomethine imines, a catalyst-free [1+2+3] cycloaddition/N–N bond cleavage sequential reaction for accessing spiroindolines with syn-stereoselectivity was developed. On the basis of experimental results and DFT calculations, peroxide and ethereal solvent were identified to trigger the hydrogen abstraction of the unstable [1+2+3] cycloaddition adducts, followed by homolytic cleavage of the N–N bond and hydrogen absorption.

中文翻译：

---

使用 C,N-环状偶氮甲亚胺对 3-(2-异氰乙基)吲哚进行顺式立体选择性 C3-螺环化和 C2-胺化

通过利用C , N环偶氮甲亚胺的未充分探索的反应模式，开发了一种无催化剂的 [1+2+3] 环加成/N-N 键断裂顺序反应，用于获得具有顺式立体选择性的螺二氢吲哚。根据实验结果和 DFT 计算，确定过氧化物和醚类溶剂会引发不稳定的 [1+2+3] 环加成加合物的夺氢，然后是 N-N 键的均裂和氢吸收。