Ito Tasuku, Seidel Falk William, Jin Xiongjie, Nozaki Kyoko
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
J Org Chem. 2022 Oct 7;87(19):12733-12740. doi: 10.1021/acs.joc.2c01302. Epub 2022 Sep 8.
2,2,6,6-Tetramethylpiperidine--oxyl (TEMPO) has been extensively utilized as a radical scavenger or an oxidation catalyst. In contrast, TEMPO as a hydrogen atom transfer (HAT) catalyst has rarely been studied. Here, we report that TEMPO, as the HAT catalyst, homolytically cleaves benzylic or allylic C-H bonds to give the corresponding alkyl radicals. Benefiting from the dual roles played by TEMPO as the HAT catalyst and the radical scavenger, the highly challenging aerobic dehydrogenation of activated alkanes to alkenes is successfully developed.
2,2,6,6-四甲基哌啶氮氧化物（TEMPO）已被广泛用作自由基清除剂或氧化催化剂。相比之下，TEMPO作为氢原子转移（HAT）催化剂的研究却很少。在此，我们报道，作为HAT催化剂的TEMPO可均裂苄基或烯丙基C-H键，生成相应的烷基自由基。受益于TEMPO作为HAT催化剂和自由基清除剂所发挥的双重作用，成功开发出了极具挑战性的活性烷烃有氧脱氢制烯烃反应。
