State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-Dimension Materials, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 201620, Shanghai, China.
Nat Commun. 2019 Feb 14;10(1):749. doi: 10.1038/s41467-019-08669-1.
Alkenylpyridines are important pharmaceutical cores as well as versatile building blocks in organic synthesis. Heck reaction represents one of the most powerful platform for the construction of aryl-substituted alkenes, nevertheless, examples for Heck type coupling of alkenes with pyridines, particularly with branched selectivity, remain elusive. Here we report a catalytic, branch-selective pyridylation of alkenes via a sulfinate assisted photoredox catalysis. This reaction proceeds through a sequential radical addition/coupling/elimination, by utilizing readily available sodium sulfinates as reusable radical precursors as well as traceless elimination groups. This versatile protocol allows for the installation of important vinylpyridines with complete branched selectivity under mild conditions. Furthermore, this catalytic manifold is successfully applied to the expedient synthesis of Triprolidine.
烯基吡啶既是重要的药物核心，也是有机合成中多功能的构建块。Heck 反应是构建芳基取代烯烃的最强大的平台之一，然而，对于烯烃与吡啶，特别是具有支链选择性的 Heck 型偶联，仍然难以实现。在这里，我们通过亚磺酸盐辅助的光氧化还原催化报告了一种催化的、支链选择性的烯基吡啶化反应。该反应通过自由基加成/偶联/消除的顺序进行，利用易得的亚磺酸钠作为可重复使用的自由基前体以及无痕迹消除基团。该多功能方案允许在温和条件下以完全支链选择性的方式进行重要的乙烯基吡啶的安装。此外，该催化体系成功地应用于特普罗啶的快速合成。
