Iodonium IonCatalyzed Domino Synthesis of Z‑Selective α,β-Diphenylthio Enones from Easily Accessible Secondary Alcohols

The application of stabilized iodonium ions in organic synthesis remains largely unexplored. Herein, a metal-free domino synthesis of Z-selective α,β-diphenylthio enones is developed from easily available benzylic secondary alcohols employing thiophenol-stabilized iodonium ion as a catalyst. This methodology was further extended to five-membered and six-membered cyclic secondary alcohols. The UV–vis experiments suggest the formation of thiol-coordinated iodine­(I) intermediates. Several control experiments establish that the reaction proceeds via the oxidation of alcohol to ketone, α-thiolation of ketones followed by α,β-unsaturation, and finally the β-thiolation of α,β-unsaturated ketones to generate bis-vinyl sulfides. The in situ-generated stabilized iodonium ion is highly efficient to catalyze multiple functional group transformations in a domino manner.

稳定化碘鎓离子（stabilized iodonium ions）在有机合成中的应用仍有待深入探索。本文以易得的苄基二级醇为原料，以苯硫酚稳定化碘鎓离子为催化剂，开发了一种无金属的Z选择性α,β-二苯硫基烯酮多米诺合成方法。该方法进一步拓展至五元环及六元环二级醇底物。紫外-可见光谱实验表明，反应过程中生成了硫醇配位的碘(I)中间体（thiol-coordinated iodine(I) intermediates）。多组对照实验证实，该反应历程为：先将醇氧化为酮，随后对酮进行α-硫代并完成α,β-不饱和化，最终对α,β-不饱和酮进行β-硫代，从而得到双乙烯基硫醚（bis-vinyl sulfides）。原位生成的稳定化碘鎓离子可高效地以多米诺方式催化多步官能团转化反应。