A highly regioselective [3+2] cyclization of alkenes with 2-iodoanilines under the irradiation of UV light is described. This general, metal-free strategy facilitates the direct preparation of 2-mono-/disubstituted indolines as well as spiroindolines through alkene carboamination in one step. Mechanistic studies suggested that the photochemical protocol proceeded via a radical pathway.

中文翻译：

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用邻碘代苯胺光诱导[3 + 2]烯烃环化：二氢吲哚的权宜之计

描述了在紫外光照射下用2-碘苯胺对烯烃的高度区域选择性的[3 + 2]环化。这种一般的无金属策略有助于一步一步通过烯烃碳氨基化直接制备2-单-/二取代的二氢吲哚以及螺二氢吲哚。机理研究表明，光化学方案是通过自由基途径进行的。