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Qian P, Zhu D, Wang X, Sun Q, Zhang S. Electrochemical Benzylic C(sp 3)-H Imidation Enabled by Benzoic Acid Derived Radicals. J Org Chem 2024; 89:6395-6404. [PMID: 38621116 DOI: 10.1021/acs.joc.4c00425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
We developed an electrochemical approach for benzylic C(sp3)-H imidation by virtue of the in situ generated oxygen-centered radicals (OCRs). The electrochemical imidation provides a complementary approach to giving distinct imide products compared with previous acyloxylation products. This protocol exhibits good site selectivity and broad substrate generality. Moreover, the utility of the OCR-mediated protocol was extended to the electrochemical oxidation of silane, and its robustness was also highlighted by the imidation of complex substrates, which would otherwise be inaccessible for previous approaches. A plausible reaction mechanism was proposed to rationalize the experimental observations.
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Affiliation(s)
- Peng Qian
- Engineering Research Center of Biomass Conversion and Pollution Prevention of Anhui Educational Institutions, Biomass-Derived, Functional Oligosaccharides Engineering Technology Research Center of Anhui Province, School of Chemistry and Material Engineering, Fuyang Normal University, Fuyang, Anhui 236037, China
| | - Dan Zhu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China
| | - Xiaoli Wang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China
| | - Qi Sun
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Sheng Zhang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China
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Liang Y, Feng J, Li H, Wang X, Zhang Y, Fan W, Zhang S, Li MB. A Hydrogen Evolution Catalyst [Co 2O 2] Metallacycle Enables Regioselective Allene C(sp 2)-H Functionalization. Angew Chem Int Ed Engl 2024; 63:e202400938. [PMID: 38329239 DOI: 10.1002/anie.202400938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/09/2024]
Abstract
Selective functionalization of allenic C(sp2)-H is an ideal approach to upgrading simple allenes to synthetically useful allenes, albeit suffering from challenges associated with inert reactivity and inferior selectivity. Inspired by energy chemistry, a catalytic hydrogen evolution reaction (HER) strategy was leveraged to selectively activate weakly acidic allene C(sp2)-H bonds in a reductive mode. An array of [Co2O2] metallacycle complexes were readily devised starting from amino acids, and they were demonstrated as robust HER catalysts, which would selectively break allenic C(sp2)-H bonds to release hydrogen. With the newly developed HER catalyst, regioselective electrochemical functionalization of allenic C(sp2)-H with alcoholic α C(sp3)-H was unprecedentedly achieved. This strategy features excellent regioselectivity, unconventional chemoselectivity, good functional-group tolerance (62 examples), and mild conditions. Mechanism experiments revealed a reactive hydroxy-coordinated cobalt(II) species in the reaction. Density functional theory (DFT) calculations were also conducted to rationalize the regioselectivity observed in the reaction.
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Affiliation(s)
- Yating Liang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601, China
| | - Jiayi Feng
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601, China
| | - Huilong Li
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601, China
| | - Xiaoli Wang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601, China
| | - Ying Zhang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601, China
| | - Weigang Fan
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601, China
| | - Sheng Zhang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601, China
| | - Man-Bo Li
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601, China
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Liu K, Lei M, Li X, Zhang X, Zhang Y, Fan W, Li MB, Zhang S. Paired electrocatalysis unlocks cross-dehydrogenative coupling of C(sp 3)-H bonds using a pentacoordinated cobalt-salen catalyst. Nat Commun 2024; 15:2897. [PMID: 38575564 PMCID: PMC10995126 DOI: 10.1038/s41467-024-47220-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 03/25/2024] [Indexed: 04/06/2024] Open
Abstract
Cross-dehydrogenative coupling of C(sp3)-H bonds is an ideal approach for C(sp3)-C(sp3) bond construction. However, conventional approaches mainly rely on a single activation mode by either stoichiometric oxidants or electrochemical oxidation, which would lead to inferior selectivity in the reaction between similar C(sp3)-H bonds. Herein we describe our development of a paired electrocatalysis strategy to access an unconventional selectivity in the cross-dehydrogenative coupling of alcoholic α C(sp3)-H with allylic (or benzylic) C-H bonds, which combines hydrogen evolution reaction catalysis with hydride transfer catalysis. To maximize the synergistic effect of the catalyst combinations, a HER catalyst pentacoordinated Co-salen is disclosed. The catalyst displays a large redox-potential gap (1.98 V) and suitable redox potential. With the optimized catalyst combination, an electrochemical cross-dehydrogenative coupling protocol features unconventional chemoselectivity (C-C vs. C-O coupling), excellent functional group tolerance (84 examples), valuable byproduct (hydrogen), and high regio- and site-selectivity. A plausible reaction mechanism is also proposed to rationalize the experimental observations.
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Affiliation(s)
- Ke Liu
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Mengna Lei
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Xin Li
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Xuemei Zhang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Ying Zhang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Weigang Fan
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Man-Bo Li
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China.
| | - Sheng Zhang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China.
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Wang T, He F, Jiang W, Liu J. Electrohydrogenation of Nitriles with Amines by Cobalt Catalysis. Angew Chem Int Ed Engl 2024; 63:e202316140. [PMID: 38124405 DOI: 10.1002/anie.202316140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 12/23/2023]
Abstract
Catalytic hydrogenation of nitriles represents an efficient and sustainable one-step synthesis of valuable bulk and fine chemicals. We report herein a molecular cobalt electrocatalyst for selective hydrogenative coupling of nitriles with amines using protons as the hydrogen source. The key to success for this reductive reaction is the use of an electrocatalytic approach for efficient cobalt-hydride generation through a sequence of cathodic reduction and protonation. As only electrons (e- ) and protons (H+ ) as the redox equivalent and hydrogen source, this general electrohydrogenation protocol is showcased by highly selective and straightforward synthesis of various functionalized and structurally diverse amines, as well as deuterium isotope labeling applications. Mechanistic studies reveal that the electrogenerated cobalt-hydride transfer to nitrile process is the rate-determining step.
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Affiliation(s)
- Tiantian Wang
- College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, 410082, Changsha, China
| | - Fangfang He
- College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, 410082, Changsha, China
| | - Wei Jiang
- College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, 410082, Changsha, China
| | - Jie Liu
- College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, 410082, Changsha, China
- Greater Bay Area Institute for Innovation, Hunan University, 511300, Guangzhou, Guangdong Province, China
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