Liu Jiaxin, Wei Yin, Shi Min
State Key Laboratory of Organometallic Chemistry, University of Chinese Academy of Sciences, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
Angew Chem Int Ed Engl. 2021 May 17;60(21):12053-12059. doi: 10.1002/anie.202101266. Epub 2021 Apr 16.
Despite allene derivatives have been always regarded as a radical accepter in traditional radical chemistry for decades, the reactivity of allene derivatives under excited state in radical chemistry was rarely explored. Herein, we wish to report an example to engage triplet-excited state of allene moiety as hydrogen-atom-transfer (HAT) partner in the activation of remote sp C-H bond via visible-light irradiation under mild reaction conditions with broad substrate scope and good functional-group tolerance. The reaction mechanism involving the generation of triplet excited state of allene derivative and the subsequent HAT process was supported by deuterium labeling, kinetic analysis experiments and DFT calculations.
尽管几十年来，丙二烯衍生物在传统自由基化学中一直被视为自由基受体，但丙二烯衍生物在自由基化学激发态下的反应活性却很少被研究。在此，我们希望报道一个例子，即在温和的反应条件下，通过可见光照射，使丙二烯部分的三重激发态作为氢原子转移（HAT）伙伴，用于活化远程sp C-H键，该反应具有广泛的底物范围和良好的官能团耐受性。氘代标记、动力学分析实验和密度泛函理论（DFT）计算支持了涉及丙二烯衍生物三重激发态的产生及随后的HAT过程的反应机理。
