德国亚琛工业大学Daniele Leonori团队宣布他们的研究显示，氢隧穿使卤素原子和基团转移反应活性得以实现。相关研究成果发表在2022年9月16日出版的《科学》。

卤素原子和基团转移反应生成碳自由基通常是通过锡和硅试剂实现的，这些试剂最大限度地发挥了焓（热力学）和极性（动力学）效应的相互作用。

该工作中，研究人员证明了在温和的光化学条件下，由量子力学隧穿启用的独特反应模式，该反应使用环己二烯衍生物γ-萜品烯作为萃取物。该协议活化烷基和芳基卤化物以及几种醇和硫醇衍生物。实验和计算研究揭示了环己二烯自由基通过有效氢原子的反应性，进行协同芳构化和卤素原子或基团提取的一种非正则途径。这种活化机制似乎在热力学和动力学上都不利，但通过量子隧穿被证明是可行的。

附：英文原文

Title: Halogen-atom and group transfer reactivity enabled by hydrogen tunneling

Author: Timothée Constantin, Bartosz Górski, Michael J. Tilby, Saloua Chelli, Fabio Juliá, Josep Llaveria, Kevin J. Gillen, Hendrik Zipse, Sami Lakhdar, Daniele Leonori

Issue&Volume: 2022-09-16

Abstract: The generation of carbon radicals by halogen-atom and group transfer reactions is generally achieved using tin and silicon reagents that maximize the interplay of enthalpic (thermodynamic) and polar (kinetic) effects. In this work, we demonstrate a distinct reactivity mode enabled by quantum mechanical tunneling that uses the cyclohexadiene derivative γ-terpinene as the abstractor under mild photochemical conditions. This protocol activates alkyl and aryl halides as well as several alcohol and thiol derivatives. Experimental and computational studies unveiled a noncanonical pathway whereby a cyclohexadienyl radical undergoes concerted aromatization and halogen-atom or group abstraction through the reactivity of an effective H atom. This activation mechanism is seemingly thermodynamically and kinetically unfavorable but is rendered feasible through quantum tunneling.

DOI: abq8663

Source: https://www.science.org/doi/10.1126/science.abq8663