State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
J Am Chem Soc. 2022 Sep 14;144(36):16316-16324. doi: 10.1021/jacs.2c07643. Epub 2022 Sep 1.
We report here an efficient and highly diastereoselective intermolecular anti-Markovnikov hydroamination of unactivated alkenes with aliphatic azides in the presence of silane. The system tolerates a wide range of azides and alkenes and operates with alkene as limiting reagent. Mechanistic studies suggest a radical chain pathway that involves aminium radical formation, radical addition to alkenes and HAT from silane to β-aminium alkyl radical. The use of sterically bulky silane is proposed to contribute to the excellent diastereoselectivity for HAT. Computational analysis uncovers the reaction pathway of aliphatic azide activation with silyl radical for aminyl radical formation.
我们在此报告了一种在硅烷存在下，脂肪族叠氮化物与未活化烯烃进行高效、高非对映选择性反马氏加成的方法。该体系可耐受多种叠氮化物和烯烃，并以烯烃为限制试剂。机理研究表明，该反应涉及氨自由基形成、自由基与烯烃加成以及硅烷向β-氨烷基自由基的 HAT。我们提出使用空间位阻大的硅烷有助于实现 HAT 的优异非对映选择性。计算分析揭示了脂肪族叠氮化物与硅基自由基反应生成氨自由基的反应途径。
