Since the discovery of the radical mediated thiol‐ene and thiol‐yne reactions, these reactions have been employed in an intramolecular manner for the synthesis of sulfur‐containing heterocycles. Although closely related on a mechanistic basis, the thiol‐ene and thiol‐yne cyclization can differ greatly in regioselectivity and product distribution, with the thiol‐ene process being more predictable and thus attracting greater utilization. Herein, we review intramolecular thiyl‐radical addition reactions and the factors leading to the observed regioselectivity in examples in which both the 5‐exo and 6‐endo mode of cyclization are feasible. We highlight the applications of these important reactions for organic synthesis in the recent literature.

中文翻译：

---

有机合成中的5-外基和6-内基巯基自由基聚合

自从发现自由基介导的硫醇和硫醇炔反应以来，这些反应已以分子内方式用于合成含硫杂环。尽管在机理上密切相关，但硫醇和硫醇炔环化的区域选择性和产物分布可能存在很大差异，硫醇的过程更可预测，因此吸引了更多的利用。在本文中，我们回顾了分子内的巯基自由基加成反应以及导致观察到的区域选择性的因素，在这些例子中，环己内酯化的5- exo和6- endo模式都是可行的。在最近的文献中，我们重点介绍了这些重要反应在有机合成中的应用。