A facile and benign catalytic route has been developed to quantitatively yield γ-valerolactone (GVL; ca. 97%) from biomass-based levulinates at room temperature to 80 °C by using easily available polymethylhydrosiloxane (PMHS) and KF as the liquid H-donor and recyclable catalyst, respectively. No extra step was required to liberate GVL from the in situ-formed siloxane, and this catalytic system exhibited a lower activation energy (40.9 kJ/mol) compared to previously reported ones. The deuterium-labeled study further demonstrated the reaction proceeding through cascade hydrosilylation and cyclization with fluoride successively acting as the nucleophile and base. In addition, the PMHS-derived resin was extremely favorable to restrain the leaching of fluoride and maintain its constant activity for at least six cycles.

中文翻译：

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高度可循环利用的氟化物，可增强级联氢化硅烷化–低温下将白蛋白形成环化成γ-戊内酯

通过使用容易获得的聚甲基氢硅氧烷（PMHS）和KF作为液体H-，已开发了一种简便而良性的催化路线，可在室温至80°C的条件下从基于生物质的乙酰丙酸酯定量产生γ-戊内酯（GVL；约97％）。供体和可循环使用的催化剂。无需额外的步骤即可从原位形成的硅氧烷中释放出GVL，与以前报道的相比，该催化体系的活化能更低（40.9 kJ / mol）。氘标记的研究进一步证明了反应是通过级联氢化硅烷化和环化进行的，氟化物依次充当亲核试剂和碱。另外，源自PMHS的树脂对于抑制氟化物的浸出并在至少六个循环中保持其恒定活性非常有利。