Low-Temperature Rapid-Scan Detection of Reactive Intermediates in Epoxidation Reactions Catalyzed by a New Enzyme Mimic of Cytochrome P450

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• 作者：Natalya Hessenauer-Ilicheva ; Alicja Franke ; Dominik Meyer ; Wolf-D. Woggon ; Rudi van Eldik
• 刊名：Journal of the American Chemical Society
• 出版年：2007
• 出版时间：October 17, 2007
• 年：2007
• 卷：129
• 期：41
• 页码：12473 - 12479
• 全文大小：226K
• 年卷期：v.129,no.41(October 17, 2007)
• ISSN：1520-5126

文摘

The use of synthetic iron(III) porphyrins as models for heme-type catalysts in biomimeticcytochrome P450 research has provided valuable information on the nature and reactivity of intermediatesproduced in the "peroxide shunt" pathway. This article reports spectroscopic detection of reactiveintermediates formed in the epoxidation reaction of cis-stilbene with m-chloroperoxybenzoic acid catalyzedby a new mimic of cytochrome P450 with a substituted RSO₃^- group (1). The application of low-temperaturerapid-scan stopped-flow techniques enabled the determination of equilibrium and rate constants for theformation and decay of all intermediates in the catalytic cycle of 1, including the rate constant for the formation(1⁺)Fe^IV=O and for oxygen transfer to the substrate. Noteworthy, the reaction of (1⁺)Fe^IV=O with cis-stilbene leads to an almost complete re-formation (95%) of the starting complex 1. The results show thatcomplex 1 is a valuable catalyst with promising properties for further applications in a biomimetic approachtoward mimicking oxygenation reactions of cytochrome P450.