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Zhang H, Sun C, Zhang X, Cheng X, Guo G, Geng W, Gong P, Zhang S, Chao M, Shen D. C-N cleavage of secondary amide to access primary amide by a Co(II)/Oxone oxidation system. Org Biomol Chem 2024; 22:8157-8162. [PMID: 39283052 DOI: 10.1039/d4ob00974f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2024]
Abstract
Cleavage of the C-N bond of a secondary amide could provide alternative access to primary amides; however, this strategy remains challenging due to oxidation resistance of the amide. Herein, we employed the cobalt(II)/Oxone catalytic system, one of the advanced oxidation processes (AOPs), to make it available to break the strong C-N bond of various secondary (sulfon)amides, especially those bearing electron-poor or ortho-substituted N-arenes, en route to desirable primary (sulfon)amides. Control experiments showed that it was probably not the generally-considered persulfate anion radical in the cobalt/peroxymonosulfate (Co/PMS) system but the proposed high-valent cobalt-oxo intermediate that should be the major active species for the initial N-H oxidation of N-aryl amides. In the case of N-alkylated secondary amides, the α-C-H bond, rather than the N-H bond, should be oxidized first by both the reactive radicals and high-valent cobalt-oxo species. This work not only establishes an efficient method for removing the N-substituents of secondary amides at low cost, with readily available and eco-friendly reagents, but also demonstrates further synthetic application and provides more insight into intermediates for metal-based AOPs in environmental remediation.
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Affiliation(s)
- Haixing Zhang
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
| | - Chaoyue Sun
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
| | - Xuan Zhang
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
| | - Xuan Cheng
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
| | - Guiwen Guo
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
| | - Wang Geng
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
| | - Peiwei Gong
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
| | - Shumiao Zhang
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
| | - Mianran Chao
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
| | - Duyi Shen
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong Province, P. R. China.
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Zhang Z, Cao X, Song X, Wang G, Shi B, Li X, Ma N, Liu L, Zhang G. Metal-free nucleophilic 7,8-dearomatization of quinolines: Spiroannulation of aminoquinoline protected amino acids. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.107779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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