美国威斯康星大学Jennifer M. Schomaker团队阐明了电氧化丙二烯二氧合机理——四甲基哌啶N-氧基（TEMPO）的双重作用。相关研究成果于2024年12月16日发表在《美国化学会杂志》。

非对称二烯烃的累积π体系包含三个不同的不饱和碳，与烯烃和炔烃相比，它们对自由基具有独特的反应性。尽管这些多功能构建块具有合成潜力，但二烯烃的电化学转化在历史上一直未得到充分探索。

多种易于获取丙二烯的策略，再加上人们对碳氢化合物可持续氧化转化的兴趣重新燃起，促使研究人员对电化学TEMPO介导的丙二烯二氧化的罕见例子进行了深入研究。所得乙烯基TEMPO基序易于后官能化，以在每个烯碳上安装杂原子。

研究人员进行了机理研究，包括循环伏安法（CV）研究、计算和操作核磁共振（ReactNMR）监测，为未来提供独特合成构建块的电化学丙二烯官能化奠定了基础。

附：英文原文

Title: Elucidating the Mechanism of Electrooxidative Allene Dioxygenation: Dual Role of Tetramethylpiperidine N-Oxyl (TEMPO)

Author: Ken S. Lee, Federico Barbieri, Emanuele Casali, Elijah T. Marris, Giuseppe Zanoni, Jennifer M. Schomaker

Issue&Volume: December 16, 2024

Abstract: The cumulated π system of a nonsymmetric allene contains three distinct unsaturated carbons that imbue it with unique reactivity toward radicals as compared to its alkene and alkyne counterparts. Despite the synthetic potential of these versatile building blocks, electrochemical transformations of allenes have been historically underexplored. Myriad strategies for easy access to allenes, coupled with the resurgence of interest in sustainable oxidative transformations of hydrocarbons, prompted our efforts to conduct an in-depth investigation of a rare example of an electrochemical TEMPO-mediated allene dioxygenation. The resultant vinyl-TEMPO motif is readily postfunctionalized to install a heteroatom at each allene carbon. Mechanistic investigations, including cyclic voltammetry (CV) studies, computations, and monitoring by operando NMR (ReactNMR) were performed to lay the groundwork for future electrochemical allene functionalizations that deliver unique synthetic building blocks.

DOI: 10.1021/jacs.4c10431

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c10431