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Wen X, Ma Y, Chen J, Wang B. A synthetically useful catalytic system for aliphatic C-H oxidation with a nonheme cobalt complex and m-CPBA. Org Biomol Chem 2024; 22:5729-5733. [PMID: 38932595 DOI: 10.1039/d4ob00807c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
We report herein a synthetically useful catalytic system for aliphatic C-H oxidation with a mononuclear nonheme cobalt(II) complex and m-chloroperbenzoic acid (m-CPBA). Preliminary mechanistic studies suggest that a high-valent cobalt-oxygen species (e.g., cobalt(IV)-oxo or cobalt(III)-oxyl) is the oxidant that effects C-H oxidation via a rate-determining hydrogen atom abstraction (HAA) step.
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Affiliation(s)
- Xiang Wen
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
| | - Yidong Ma
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
| | - Jie Chen
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
| | - Bin Wang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
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Cheng J, Shiota Y, Yamasaki M, Izukawa K, Tachi Y, Yoshizawa K, Shimakoshi H. Mechanistic Study for the Reaction of B 12 Complexes with m-Chloroperbenzoic Acid in Catalytic Alkane Oxidations. Inorg Chem 2022; 61:9710-9724. [PMID: 35696150 DOI: 10.1021/acs.inorgchem.2c01174] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxidation of alkanes with m-chloroperbenzoic acid (mCPBA) catalyzed by the B12 derivative, heptamethyl cobyrinate, was investigated under several conditions. During the oxidation of cyclohexane, heptamethyl cobyrinate works as a catalyst to form cyclohexanol and cyclohexanone at a 0.67 alcohol to ketone ratio under aerobic conditions in 1 h. The reaction rate shows a first-order dependence on the [catalyst] and [mCPBA] while being independent of [cyclohexane]; Vobs = k2[catalyst][mCPBA]. The kinetic deuterium isotope effect was determined to be 1.86, suggesting that substrate hydrogen atom abstraction is not dominantly involved in the rate-determining step. By the reaction of mCPBA and heptamethyl cobyrinate at low temperature, the corresponding cobalt(III)acylperoxido complex was formed which was identified by UV-vis, IR, ESR, and ESI-MS studies. A theoretical study suggested the homolysis of the O-O bond in the acylperoxido complex to form Co(III)-oxyl (Co-O•) and the m-chlorobenzoyloxyl radical. Radical trapping experiments using N-tert-butyl-α-phenylnitrone and CCl3Br, product analysis of various alkane oxidations, and computer analysis of the free energy for radical abstraction from cyclohexane by Co(III)-oxyl suggested that both Co(III)-oxyl and the m-chlorobenzoyloxyl radical could act as hydrogen-atom transfer reactants for the cyclohexane oxidation.
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Affiliation(s)
- Jiamin Cheng
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744, Nishi-ku, Motooka, Fukuoka 819-0395, Japan
| | - Yoshihito Shiota
- Institute for Materials Chemistry and Engineering, Kyushu University, 744, Nishi-ku, Motooka, Fukuoka 819-0395, Japan
| | - Mikako Yamasaki
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - Kureha Izukawa
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - Yoshimitsu Tachi
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering, Kyushu University, 744, Nishi-ku, Motooka, Fukuoka 819-0395, Japan
| | - Hisashi Shimakoshi
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744, Nishi-ku, Motooka, Fukuoka 819-0395, Japan
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Catalytic Oxidations with Meta-Chloroperoxybenzoic Acid (m-CPBA) and Mono- and Polynuclear Complexes of Nickel: A Mechanistic Outlook. Catalysts 2021. [DOI: 10.3390/catal11101148] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Selective catalytic functionalization of organic substrates using peroxides as terminal oxidants remains a challenge in modern chemistry. The high complexity of interactions between metal catalysts and organic peroxide compounds complicates the targeted construction of efficient catalytic systems. Among the members of the peroxide family, m-chloroperoxybenzoic acid (m-CPBA) exhibits quite complex behavior, where numerous reactive species could be formed upon reaction with a metal complex catalyst. Although m-CPBA finds plenty of applications in fine organic synthesis and catalysis, the factors that discriminate its decomposition routes under catalytic conditions are still poorly understood. The present review covers the advances in catalytic C–H oxidation and olefine epoxidation with m-CPBA catalyzed by mono- and polynuclear complexes of nickel, a cheap and abundant first-row transition metal. The reaction mechanisms are critically discussed, with special attention to the O–O bond splitting route. Selectivity parameters using recognized model hydrocarbon substrates are summarized and important factors that could improve further catalytic studies are outlined.
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