Silver(II) and Silver(III) Intermediates in Alkene Aziridination with a Dinuclear Silver(I) Nitrene Transfer Catalyst
Silver(II) and Silver(III) Intermediates in Alkene Aziridination with a Dinuclear Silver(I) Nitrene Transfer Catalyst
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DOI：
10.1021/acscatal.0c00065
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发表时间：
2020-04-17
期刊：
影响因子：
12.9
通讯作者：
Campbell, Michael G.
中科院分区：
文献类型：
--
作者：
Elkoush, Tasneem;Mak, Choi L.;Campbell, Michael G.
近年来，利用银开发了合成上有用的均相催化，包括氮烯转移反应形成碳-氮键。然而，银催化的氧化还原反应的机制通常仍然知之甚少，包括几乎完全缺乏氧化中间体的数据。在这里，我们提出了一个详细的实验研究的双核银（I）氮烯转移催化剂的氧化与常用的高价碘氧化剂（PhINSO 2 Ar），包括结构表征的例子银（II）的氧化产物在催化相关的条件下获得。此外，银（I）催化剂显示经历逐步氧化成银（II）和银（III）中间体;银（III）中间体的产生先前在氮烯转移催化中未被证明。与先前的机理假设相反，我们的数据表明，氮烯转移发生在该反应体系中的银（III）。
In recent years, synthetically useful homogeneous catalysis has been developed with silver, including nitrene transfer reactions for carbon-nitrogen bond formation. However, the mechanisms of silver-catalyzed redox reactions are generally still poorly understood, including a near-total lack of data on oxidized intermediates. Here, we present a detailed experimental study on the oxidation of a dinuclear silver(I) nitrene transfer catalyst with commonly used hypervalent iodine oxidants (PhINSO2Ar), including structurally characterized examples of silver(II) oxidation products obtained under catalytically relevant conditions. Furthermore, the silver(I) catalyst is shown to undergo stepwise oxidation to silver(II) and silver(III) intermediates; the generation of silver(III) intermediates has not previously been demonstrated in nitrene transfer catalysis. In contrast to prior mechanistic hypotheses, our data indicates that nitrene transfer occurs from silver(III) in this reaction system.