Photoredox Asymmetric Nucleophilic Dearomatization of Indoles with Neutral Radicals
Photoredox Asymmetric Nucleophilic Dearomatization of Indoles with Neutral Radicals
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吲哚与中性自由基的光氧化还原不对称亲核脱芳构化
DOI：
10.1021/acscatal.0c04696
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发表时间：
2021
期刊：
影响因子：
12.9
通讯作者：
Wang, Wei
中科院分区：
文献类型：
--
作者：
Zhang, Yueteng;Ji, Peng;Gao, Feng;Huang, He;Zeng, Fanxun;Wang, Wei
吲哚的脱芳化是获得高价值吲哚的最有效方法。吲哚固有的亲核反应性决定了在e -和e -过程中吲哚脱芳化的发展。然而，缺乏电子的吲哚的脱芳构化一直具有挑战性。在这里，我们引入了一种概念上不同的光氧化还原介导的吉斯型转化策略，该策略通常用于将自由基共轭加成到简单的α， β-不饱和体系中，以化学选择性地破坏嵌入在芳香结构中的C = C键。此外，Oppolzer樟脑丹手性助剂还实现了挑战性中性自由基的高度非对映选择性加成。结构多样的胺功能化手性吲哚具有不同的功能和立体化学多样性，是由广泛的胺作为自由基前体产生的。此外，温和的，强大的歧管是复杂的天然产品和药物的后期修饰能力。进行DFT研究以阐明所观察到的立体化学结果。
The dearomatization of indoles represents the most efficient approach for accessing highly valued indolines. The inherent nucleophilic reactivity of indoles has dictated indole dearomatization development in both 1e–and 2e–processes. However, the dearomatization of electron-deficient indoles has been challenging. Herein, we introduce a conceptually distinct photoredox-mediated Giese-type transformation strategy, which is generally used for the conjugate addition of radicals to simple α, β-unsaturated systems, for chemoselectively breaking C═C bonds embedded in the aromatic structure. Moreover, highly diastereoselective addition of challenging neutral radicals has been achieved by Oppolzer camphorsultam chiral auxiliary. Structurally diverse amine-functionalized chiral indolines carrying distinct functional and stereochemical diversity are produced from a wide array of amines as radical precursors. Furthermore, the mild, powerful manifold is capable of the late-stage modification of complex natural products and pharmaceuticals. DFT studies are performed to elucidate the observed stereochemical outcomes.