美国波士顿学院Dunwei Wang成功利用电化学引发的链式反应实现呋喃衍生物的转化。这一研究成果发表在2021年1月14日出版的国际学术期刊《德国应用化学》上。

在该文中，研究人员报道了一个将生物质衍生的C5/C6化合物与高附加值燃料前体耦合的电化学方法。仅使用2%的有效电荷，2-甲基呋喃被氧化为一个阳离子自由基，然后与3-己烯-2,5-二酮（一种2,5-二甲基呋喃衍生物）反应，生成3-(5-甲基呋喃-2-基)己烷-2,5-二酮。该产物可以以优异的产率一步转化为4-乙基壬烷（一种生物燃料）。

更重要的是，该反应对氧气不敏感，微量的水甚至可以促进该反应。进一步机理研究证实了假设的反应途径。该反应机理中的关键是一个电化学推动的自由基生成过程。该自由基在每个反应循环的最后又被再生出来，以确保链增长以约47倍的速率进行，导致表观法拉第效率高达4700%。

附：英文原文

Title: Electrochemically‐Triggered Chain Reactions for the Conversion of Furan Derivatives

Author: Rong Chen, Cangjie Yang, Zefeng Zhou, Fredrik Haeffner, Alinda Dersjant, Nicholas Dulock, Qi Dong, Da He, Jing Jin, Yanyan Zhao, Jia Niu, Dunwei Wang

Issue&Volume: 14 January 2021

Abstract: We report an electrochemical method for coupling biomass‐derived C5/C6 compounds to value‐added fuel precursors.  Using only 2% of equivalent charges, 2‐methylfuran (2‐MF) was oxidized to yield a cation radical, which readily reacted with 3‐hexene‐2,5‐dione, a derivate of 2,5‐dimethylfuran, to produce 3‐(5‐methylfuran‐2‐yl)hexane‐2,5‐dione.  The product was converted to 4‐ethylnonane (a component of biodiesel/jet fuel) in a single step in excellent yield. Importantly, the reaction was not sensitive to oxygen, and a trace amount of water was found to promote the reaction. Detailed mechanistic studies confirmed the proposed reaction pathways.  Key to the mechanism is the radical generation that is enabled by electrochemistry. The radical is regenerated at the end of a reaction cycle to ensure chain propagation for an average of ca. 47 times, resulting in an apparent Faradaic efficiency of 4,700%.

DOI: 10.1002/anie.202016601

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202016601