College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, Zhejiang, P. R. China.
J Org Chem. 2021 Jan 15;86(2):1789-1801. doi: 10.1021/acs.joc.0c02631. Epub 2021 Jan 4.
The regioselective arylation of inert C3-H bonds in indoles reacting with arylboronates effective copper-mediated catalysis with the aid of a facile and removable 2-pyridinylisopropyl (PIP) group without ligand participation is reported. This newly established method features high compatibility with diverse functional groups between coupling partners, including both indole substrates and arylboron reagents, consequentially leading to operational simplicity and providing access to generate the desired arylated products in good to excellent yields of up to 97%. Synthetically, the PIP-derived amide moiety could subsequently be readily removed under mild reaction conditions to produce useful indole carboxylic acids for further transformation.
本文报道了一种在无需配体参与的情况下，通过简便且可去除的 2-吡啶基异丙基（PIP）基团辅助有效铜介导催化，实现吲哚与芳基硼酸酯反应中惰性 C3-H 键的区域选择性芳基化。该新方法在偶联伙伴之间具有高度的官能团兼容性，包括吲哚底物和芳基硼酸试剂，因此操作简单，并能够以高达 97%的良好至优异收率生成所需的芳基化产物。在合成上，PIP 衍生的酰胺部分可以在温和的反应条件下轻易去除，以生成用于进一步转化的有用吲哚羧酸。
