Identification of a cobalt(IV)–oxo intermediate as an active oxidant in catalytic oxidation reactions
- 주제(키워드) chemoselectivity , cobalt–oxo intermediate , epoxidation , hydroxylation , oxygen non-rebound mechanism
- 등재 SCIE, SCOPUS, KCI등재
- 발행기관 John Wiley and Sons Inc
- 발행년도 2022
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000193643
- 본문언어 영어
- Published As https://doi.org/10.1002/bkcs.12584
초록/요약
We report the catalytic oxidation of organic substrates by a cobalt complex, [CoIII(TAML)]− (TAML = tetra-amido macrocyclic ligand), and meta-chloroperbenzoic acid (m-CPBA) under the mild reaction conditions and the identification of a cobalt(IV)–oxo intermediate, [CoIV(TAML)(O)]2−, as an active oxidant in the catalytic oxidation reactions. In the hydroxylation of cyclohexane, cyclohexanol is the sole product and the hydroxylation reaction occurs via an oxygen non-rebound mechanism. Kinetic isotope effect value of 3.1, obtained in the oxidation of cyclohexane-h12/d12, indicates that a hydrogen atom abstraction from cyclohexane by the cobalt(IV)–oxo complex is the rate-determining step. The catalytic oxidation of cyclohexene prefers the C═C bond epoxidation to the C–H bond activation, yielding cyclohexene oxide as a sole product. In the epoxidation of cis- and trans-stilbenes, cis- and trans-stilbene oxides, respectively, are yielded stereoselectively. The present study reports a highly selective catalytic oxidation of organic substrates by a cobalt complex and m-CPBA and the involvement of a cobalt(IV)–oxo intermediate as an active oxidant in the catalytic oxidation reactions. © 2022 Korean Chemical Society, Seoul & Wiley-VCH GmbH.
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