Photocatalytic α-Alkylation of Amines with Alkyl Halides
Photocatalytic α-Alkylation of Amines with Alkyl Halides
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DOI：
10.1021/acscatal.0c04519
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发表时间：
2020-11-20
期刊：
影响因子：
12.9
通讯作者：
Ready, Joseph M.
中科院分区：
文献类型：
--
作者：
Leng, Lingying;Ready, Joseph M.
α-支化胺是有机合成的基本构件。它们传统上是通过亚胺的亲核加成制备的。这些方法通常需要高活性的有机金属试剂，并在严格的空气和无湿条件下进行。在这里，我们描述了一种替代方法，它涉及到胺与烷基溴的C-烷基化反应。从机理上讲，该反应可能包括光催化生成α-氨基和稳定的碳中心自由基(烯丙基、苄基、α-羰基)，然后进行自由基复合。这种方法提供了一种温和的、原子经济的、氧化还原中性的α-支化胺的合成方法，具有广泛的应用范围，并且避免了预金属化试剂。
alpha-Branched amines represent essential building blocks for organic synthesis. They are traditionally prepared through nucleophilic addition to imines. These methods often require highly reactive organometallic reagents and proceed under rigorous air- and moisture-free conditions. Here we describe an alternative approach that involves a C-alkylation of amines with alkyl bromides. Mechanistically, the reaction likely involves photocatalytic generation of an alpha-amino radical and a stabilized carbon-centered radical (allyl, benzyl, alpha-carbonyl) followed by radical recombination. This approach offers a mild, atom-economical, redox neutral synthesis of alpha-branched amines that shows broad scope and avoids premetalated reagents.