Arenes are fundamental feedstocks for many chemical processes within organic synthesis. The dearomatization of arenes, especially non-activated benzene derivatives, has long been recognized as an important synthetic transformation. However, developing enantioselective variants of these dearomative reactions remains a challenge due to the inherent stability of benzene derivatives. Here we report the development of a samarium diiodide (SmI₂)-mediated enantioselective reductive dearomatization of non-activated benzene derivatives. The use of chiral tridentate aminodiol ligand forms a chiral samarium complex, mediating the intramolecular addition of a ketyl radical onto one of the two enantiotopic arene rings in a stereoselective fashion. The scope of the process is displayed through the synthesis of a range of dearomatized bicycles bearing three stereogenic centres, in good yield and stereocontrol. Scale-up of the process and further reductive and olefination transformations of the bicyclic products showed the synthetic utility of the SmI₂-mediated process.

芳烃是有机合成中许多化学过程的基本原料。芳烃，尤其是非活化苯衍生物的脱芳构化，长期以来被认为是一种重要的合成转化。然而，由于苯衍生物的固有稳定性，开发这些脱芳烃反应的对映选择性变体仍然是一个挑战。在这里，我们报告了二碘化钐（SmI ₂)介导的非活化苯衍生物的对映选择性还原脱芳构化。使用手性三齿氨基二醇配体形成手性钐络合物，介导酮基以立体选择性方式在两个对映体芳烃环之一上的分子内加成。该过程的范围通过合成一系列带有三个立体中心的脱芳构化自行车来展示，这些自行车具有良好的产量和立体控制。该工艺的放大以及双环产物的进一步还原和烯化转化显示了SmI ₂介导的工艺的合成效用。