Wang Lei, Lin Chuiyi, Chong Qinglei, Zhang Zhihan, Meng Fanke
State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, 345 Lingling Road, 200032, Shanghai, China.
CCNU-uOttawa Joint Research Center, Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Louyu Road, Wuhan, 430079, Hubei, China.
Nat Commun. 2023 Aug 10;14(1):4825. doi: 10.1038/s41467-023-40488-3.
Catalytic enantioselective introduction of a propargyl group constitutes one of the most important carbon-carbon forming reactions, as it is versatile to be transformed into diverse functional groups and frequently used in the synthesis of natural products and biologically active molecules. Stereoconvergent transformations of racemic propargyl precursors to a single enantiomer of products via propargyl radicals represent a powerful strategy and provide new reactivity. However, only few Cu- or Ni-catalyzed protocols have been developed with limited reaction modes. Herein, a photoredox/cobalt-catalyzed regio-, diastereo- and enantioselective propargyl addition to aldehydes via propargyl radicals is presented, enabling construction of a broad scope of homopropargyl alcohols that are otherwise difficult to access in high efficiency and stereoselectivity from racemic propargyl carbonates. Mechanistic studies and DFT calculations provided evidence for the involvement of propargyl radicals, the origin of the stereoconvergent process and the stereochemical models.
催化对映选择性引入炔丙基是最重要的碳-碳形成反应之一，因为它可以灵活地转化为各种官能团，并常用于天然产物和生物活性分子的合成。通过炔丙基自由基将外消旋炔丙基前体立体汇聚转化为单一对映体产物是一种强大的策略，并提供了新的反应活性。然而，目前仅开发了少数铜或镍催化的方法，且反应模式有限。在此，我们报道了一种光氧化还原/钴催化的通过炔丙基自由基对醛进行区域、非对映和对映选择性炔丙基加成反应，能够构建一系列广泛的高炔丙醇，而这些高炔丙醇难以从外消旋炔丙基碳酸酯以高效率和立体选择性获得。机理研究和密度泛函理论（DFT）计算为炔丙基自由基的参与、立体汇聚过程的起源以及立体化学模型提供了证据。
