单线态氧介导的醚类烃中 C-H 键的选择性过氧氢化。
Singlet oxygen-mediated selective C-H bond hydroperoxidation of ethereal hydrocarbons.
机构信息
Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan.
Department of Applied Chemistry, National Chiayi University, Chiayi, 60004, Taiwan.
出版信息
Nat Commun. 2017 Nov 27;8(1):1812. doi: 10.1038/s41467-017-01906-5.
Singlet O is a key reactive oxygen species responsible for photodynamic therapy and is generally recognized to be chemically reactive towards C=C double bonds. Herein, we report the hydroperoxidation/lactonization of α-ethereal C-H bonds by singlet O (Δ) under exceptionally mild conditions, i.e., room temperature and ambient pressure, with modest to high yields (38~90%) and excellent site selectivity. Singlet O has been known for > 90 years, but was never reported to be able to react with weakly activated C-H bonds in saturated hydrocarbons. Theoretical calculations indicate that singlet O directly inserts into the α-ethereal C-H bond in one step with conservation of steric configuration in products. The current discovery of chemical reaction of singlet oxygen with weakly activated solvent C-H bonds, in addition to physical relaxation pathway, provides an important clue to a 35-year-old unresolved mystery regarding huge variations of solvent dependent lifetime of singlet O.
单线态氧是一种关键的活性氧物种，负责光动力疗法，通常被认为对 C=C 双键具有化学活性。在此，我们报道了在异常温和的条件下（即室温、常压），通过单线态氧（Δ）引发α-醚 C-H 键的过氧氢化/内酯化反应，产率适中到较高（38%~90%），且具有极好的位点选择性。单线态氧已经存在了超过 90 年，但从未有报道称它能够与饱和烃中弱活化的 C-H 键反应。理论计算表明，单线态氧直接在一步中插入α-醚 C-H 键，产物的空间构型得以保留。目前发现单线态氧与弱活化的溶剂 C-H 键之间发生化学反应，除了物理弛豫途径外，还为解决与溶剂依赖性单线态氧寿命存在巨大差异相关的 35 年未解之谜提供了重要线索。
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