Metalloradical approach for concurrent control in intermolecular radical allylic C−H amination
Metalloradical approach for concurrent control in intermolecular radical allylic C−H amination
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DOI：
10.1038/s41557-022-01119-4
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发表时间：
2023-01
期刊：
影响因子：
21.8
通讯作者：
Pan Xu;J. Xie;Duo-Sheng Wang;X. Zhang
中科院分区：
文献类型：
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作者：
Pan Xu;J. Xie;Duo-Sheng Wang;X. Zhang
虽然自由基化学具有巨大的潜力，但其高反应活性和多样的反应途径给有机合成带来了困难。除了区分多个竞争途径外，自由基反应中各种选择性的控制既提出了巨大的挑战，也带来了巨大的机遇。为了调节化学选择性和区域选择性，以及非对映选择性和对映选择性，需要制定概念上新的方法和根本不同的管理原则。在这里，我们表明，钴（II）为基础的金属自由基催化，使自由基化学选择性烯丙基C-H键的分子间胺化，通过采用模块化设计的D2-对称手性amidoporphyrins与可调的口袋样环境作为支持配体。该反应在一次催化操作中表现出区域选择性、非对映选择性和对映选择性的显着收敛。除了证明金属自由基催化在控制均裂自由基反应中的独特机会之外，Co（II）催化的会聚C-H胺化提供了一种直接从烯烃的异构体混合物合成有价值的手性α-叔胺的途径。
Although they offer great potentials, the high reactivity and diverse pathways of radical chemistry pose difficult problems for applications in organic synthesis. In addition to the differentiation of multiple competing pathways, the control of various selectivities in radical reactions presents both formidable challenges and great opportunities. To regulate chemoselectivity and regioselectivity, as well as diastereoselectivity and enantioselectivity, calls for the formulation of conceptually new approaches and fundamentally different governing principles. Here we show that Co(II)-based metalloradical catalysis enables the radical chemoselective intermolecular amination of allylic C−H bonds through the employment of modularly designedD2-symmetric chiral amidoporphyrins with a tunable pocket-like environment as the supporting ligand. The reaction exhibits a remarkable convergence of regioselectivity, diastereoselectivity and enantioselectivity in a single catalytic operation. In addition to demonstrating the unique opportunities of metalloradical catalysis in controlling homolytic radical reactions, the Co(II)-catalysed convergent C–H amination offers a route to synthesize valuable chiral α-tertiary amines directly from an isomeric mixture of alkenes.