Hitoshio Kenshiro, Shimokawa Jun, Yorimitsu Hideki
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
Angew Chem Int Ed Engl. 2025 May;64(21):e202424183. doi: 10.1002/anie.202424183. Epub 2025 Mar 24.
Silicon-containing compounds are increasingly vital in pharmaceutical and agrochemical applications, yet existing silylation methods face critical limitations: poor reactivity of unactivated silanes and instability of activated silylation reagents and their products. Here, we present a seven-membered dialkoxysilyl unit, dioxasilepane, abbreviated as Si(pan), that combines exceptional stability with controllable reactivity. We demonstrate a versatile method for Si(pan)Me incorporation into organic molecules through reactions with diverse aryl, alkenyl, and alkyl chlorides. Notably, we have isolated and structurally characterized the key silylpotassium intermediate as its 18-crown-6 complex through X-ray crystallography. Experimental mechanistic studies reveal that this silylpotassium species mediates the transformation primarily through halogen-metal exchange (HME). Computational investigations confirm the HME pathway while suggesting a concurrent S2 mechanism for specific primary alkyl chlorides. This methodology establishes Si(pan) as a robust building block for constructing silicon-containing molecular frameworks, addressing a longstanding challenge in organic synthesis.
含硅化合物在制药和农用化学品应用中越来越重要，但现有的硅烷化方法面临着关键限制：未活化硅烷的反应性差以及活化硅烷化试剂及其产物的不稳定性。在此，我们提出了一种七元二烷氧基硅基单元，二氧杂硅庚烷，简称为Si(pan)，它兼具出色的稳定性和可控的反应性。我们展示了一种通用方法，可通过与各种芳基、烯基和烷基氯化物反应将Si(pan)Me引入有机分子中。值得注意的是，我们通过X射线晶体学分离并对关键的硅钾中间体作为其18-冠-6配合物进行了结构表征。实验机理研究表明，这种硅钾物种主要通过卤-金属交换（HME）介导转化。计算研究证实了HME途径，同时表明特定伯烷基氯化物存在并发的S2机制。该方法将Si(pan)确立为构建含硅分子框架的强大构件，解决了有机合成中一个长期存在的挑战。
