Exceedingly Fast Oxygen Atom Transfer to Olefins via a Catalytically Competent Nonheme Iron Species.
Exceedingly Fast Oxygen Atom Transfer to Olefins via a Catalytically Competent Nonheme Iron Species.
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DOI：
10.1002/anie.201601396
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发表时间：
2016-05
影响因子：
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通讯作者：
J. Serrano-Plana;A. Aguinaco;R. Belda;E. Garcı́a-España;M. G. Basallote;A. Company;M. Costas
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文献类型：
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作者：
J. Serrano-Plana;A. Aguinaco;R. Belda;E. Garcı́a-España;M. G. Basallote;A. Company;M. Costas
[Fe（CF 3 SO 3）2（PyNMe 3）]与过量的过氧乙酸在-40 °C下的反应导致亚稳化合物的积累，该亚稳化合物以快速平衡的一对电聚合物质[Fe（III）（OOAc）（PyNMe 3）]（2+）和[Fe（V）（O）（OAc）（PyNMe 3）]（2+）存在。停流UV/维斯分析证实，从这些电子聚合物到烯烃底物的氧原子转移（OAT）非常快，形成具有立体保留的环氧化物。的电子和空间位阻性质的基板上的反应速率的影响，可以阐明，和催化氧化确定的相对反应性可以通过动力学研究再现。所观察到的快速反应速率和高选择性表明，这种亚稳化合物是一种真正胜任的OAT中间体，与非血红素铁催化的环氧化反应相关。
The reaction of [Fe(CF3 SO3 )2 (PyNMe3 )] with excess peracetic acid at -40 °C leads to the accumulation of a metastable compound that exists as a pair of electromeric species, [Fe(III) (OOAc)(PyNMe3 )](2+) and [Fe(V) (O)(OAc)(PyNMe3 )](2+) , in fast equilibrium. Stopped-flow UV/Vis analysis confirmed that oxygen atom transfer (OAT) from these electromeric species to olefinic substrates is exceedingly fast, forming epoxides with stereoretention. The impact of the electronic and steric properties of the substrate on the reaction rate could be elucidated, and the relative reactivities determined for the catalytic oxidations could be reproduced by kinetic studies. The observed fast reaction rates and high selectivities demonstrate that this metastable compound is a truly competent OAT intermediate of relevance for nonheme iron catalyzed epoxidations.