Theoretical investigation on the elusive biomimetic iron(III)-iodosylarene chemistry: An unusual hydride transfer triggers the Ritter reaction
Theoretical investigation on the elusive biomimetic iron(III)-iodosylarene chemistry: An unusual hydride transfer triggers the Ritter reaction
复制标题
对难以捉摸的仿生铁(III)-碘代芳烃化学的理论研究：不寻常的氢化物转移触发里特反应
DOI：
10.1016/j.cclet.2021.05.030
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发表时间：
2021-12-01
影响因子：
9.1
通讯作者：
Wang, Yong
中科院分区：
文献类型：
--
作者：
Gao, Lanping;Chen, Xiaolu;Wang, Yong
将碘分子引入仿生非血红素化学中，在识别精细的金属-氧反应中间体方面取得了很大的成就。然而，经过三十多年的实验和理论努力，金属-碘代芳烃加合物的性质以及与之相关的一种氧化剂/多种氧化剂的二分争论仍然是一个推测问题。在这里，我们报道了一种著名的铁(III)-碘杂菲配合物FeIII(PHIO)(OTf)(3)(1)在环己烯氧化反应中的构效关系的理论研究。计算结果表明，作为C-H键和C=C键的区域选择性攻击的反应，1通过调整其作为2E-氧化剂或氧供体的角色，表现出变色龙的行为。1的氧化C-H键的活化首次被发现是通过一种新的氢化物转移过程来形成环己烯碳正离子中间体，这种无反弹步骤触发Ritter反应摄取乙腈分子形成酰胺产物，或者继续进行羟基的反弹返回溶剂笼形成羟基化产物。而在C=C键的活化中，1是一个正常的氧供体，通过直接氧原子转移机制呈现出环氧化物产物的两态反应活性。这些机制发现符合并解释了著名的瓦伦丁实验，并丰富了生物无机化学中的无反弹情景。(C)爱思唯尔公司代表中国化学会和中国医学科学院中药研究所出版的《2021年》。
Introduction of iodosylarnes into biomimetic nonheme chemistry has made great achievement on identification of the subtle metal-oxygen reaction intermediates. However, after more than three decades of experimental and theoretical efforts the nature of the metal-iodosylarene adducts and the related dichotomous one-oxidant/multiple-oxident controversy have remained a matter of speculation. Herein, we report a theoretical study of the structure-activity relationship of the noted iron(III)-iodsylarene complex, FeIII (PhIO)(OTf)(3) (1), in oxygenation of cyclohexene. The calculated results revealed that 1 behaves like a chameleon by adapting its roles as a 2e-oxidant or an oxygen donor, as a response to the regioselective attack of the C-H bond and the C=C bond. The oxidative C-H bond activation by 1 was found, for the first time, to proceed via a novel hydride transfer process to form a cyclohexene carbonium intermediate, such non-rebound step triggers the Ritter reaction to uptake an acetonitrile molecule to form the amide product, or proceeds with the rebound of the hydroxyl group return to the solvent cage to form the hydroxylated product. While in the C=C bond activation, 1 is a normal oxygen donor and shows two-state reactivity to present the epoxide product via a direct oxygen atom transfer mechanism. These mechanistic findings fit and explain the famous Valentine's experiments and enrich the non-rebound scenario in bioinorganic chemistry. (C) 2021 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.