Bai Jian-Fei, Yasumoto Kento, Kano Taichi, Maruoka Keiji
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto, 606-8502, Japan.
Current address: Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences, Lanzhou, 730000, P. R. China.
Angew Chem Int Ed Engl. 2019 Jun 24;58(26):8898-8901. doi: 10.1002/anie.201904520. Epub 2019 May 24.
A highly enantioselective synthesis of 1,4-enynes is described that proceeds through an organocatalytic reaction between propargyl alcohols and trialkenylboroxines. Our strategy relies on acid-mediated generation of the carbocationic intermediate from propargyl alcohols followed by enantioselective alkenylation with trialkenylboroxines. A range of chiral 1,4-enynes were obtained in moderate to good yields with high levels of enantioselectivity. Use of a highly acidic chiral N-triflyl phosphoramide catalyst, which has two distant Lewis basic oxygen atoms, was found to be crucial for both high reactivity and selectivity in the present reaction.
本文描述了一种1,4-烯炔的高对映选择性合成方法，该方法通过炔丙醇与三烯基硼酸酯之间的有机催化反应进行。我们的策略依赖于酸介导的炔丙醇生成碳正离子中间体，然后与三烯基硼酸酯进行对映选择性烯基化反应。一系列手性1,4-烯炔以中等至良好的产率和高对映选择性得到。发现使用具有两个远距离路易斯碱性氧原子的高酸性手性N-三氟甲磺酰基磷酰胺催化剂对于本反应中的高反应性和选择性至关重要。
