Iridium-Catalyzed Direct C4-and C7-Selective Alkynylation of Indoles Using Sulfur-Directing Groups
Iridium-Catalyzed Direct C4-and C7-Selective Alkynylation of Indoles Using Sulfur-Directing Groups
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DOI：
10.1002/anie.201904709
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发表时间：
2019-07-15
影响因子：
16.6
通讯作者：
Miura, Masahiro
中科院分区：
文献类型：
--
作者：
Kona, Chandrababu Naidu;Nishii, Yuji;Miura, Masahiro
吲哚及其类似物是过去世纪中最常见的杂环化合物之一，人们对其衍生物进行了广泛的研究，以建立实用的合成方法。特别是，在吡咯环上选择性官能化反应性差的苯型核是一个很大的挑战。本文报道了在硫导向基团的帮助下，铱催化的吲哚C4-和C7-位置的直接炔基化。这种转换显示了广泛的功能基团的宽容与特殊的网站选择性。导向基团可以容易地去除或在催化后转化。炔片段的合成效用通过衍生成天然吲哚生物碱的核心结构来证明。
Indoles and their analogues have been one of the most ubiquitous heterocycles during the past century, and extensive studies have been conducted to establish practical synthetic methods for their derivatives. In particular, selective functionalization of the poorly reactive benzenoid core over the pyrrole ring has been a great challenge. Reported herein is an iridium-catalyzed direct alkynylation of the indole C4- and C7-positions with the assistance of sulfur directing groups. This transformation shows a wide range of functional-group tolerance with exceptional site selectivity. The directing group can be either easily removed or transformed after catalysis. The synthetic utility of the alkyne fragment is demonstrated by the derivatization into the core structure of natural indole alkaloids.