Mechanism of Oxidative Amidation of Nitroalkanes with Oxygen and Amine Nucleophiles by Using Electrophilic Iodine
Mechanism of Oxidative Amidation of Nitroalkanes with Oxygen and Amine Nucleophiles by Using Electrophilic Iodine
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DOI：
10.1002/chem.201600540
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发表时间：
2016-04-11
影响因子：
4.3
通讯作者：
Hayashi, Yujiro
中科院分区：
文献类型：
--
作者：
Li, Jing;Lear, Martin J.;Hayashi, Yujiro
最近，我们开发了一种直接将伯基硝基烷烃氧化转化为酰胺的方法，该方法需要将碘源与胺、碱和氧混合。在此，我们系统地研究了这些方法的机理和可能的中间体。我们的结论是，胺-碘配合物首先是通过N-卤键形成的。这个络合物与ACI-硝酸盐反应生成-碘和-二碘硝烷，它们可以作为亲电碘的替代来源，也可以在O-2下生成额外的等摩尔量的I+。特别是，证据支持，-二碘硝烷中间体与分子氧反应形成过氧加合物；或者，这些四面体中间体厌氧重排形成可裂解的亚硝酸酯。在任何一种情况下，都建议形成活化酯，最终以传统方式与亲核胺反应。
Recently, we developed a direct method to oxidatively convert primary nitroalkanes into amides that entailed mixing an iodonium source with an amine, base, and oxygen. Herein, we systematically investigated the mechanism and likely intermediates of such methods. We conclude that an amine-iodonium complex first forms through N-halogen bonding. This complex reacts with aci-nitronates to give both -iodo- and ,-diiodonitroalkanes, which can act as alternative sources of electrophilic iodine and also generate an extra equimolar amount of I+ under O-2. In particular, evidence supports ,-diiodonitroalkane intermediates reacting with molecular oxygen to form a peroxy adduct; alternatively, these tetrahedral intermediates rearrange anaerobically to form a cleavable nitrite ester. In either case, activated esters are proposed to form that eventually reacts with nucleophilic amines in a traditional fashion.