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Zhang Z, Gong Y, Xue X, Hu M, Zhou M, Zhao Y, Hu Z. One-Step Green Synthesis of Isoeugenol Methyl Ether from Eugenol by Dimethyl Carbonate and Phase-Transfer Catalysts. Molecules 2024; 29:551. [PMID: 38276627 PMCID: PMC10820531 DOI: 10.3390/molecules29020551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024] Open
Abstract
In this paper, the green synthesis of isoeugenol methyl ether (IEME) from eugenol by O-methylation and isomerization is completed using a one-step green process. In the methylation reaction, dimethyl carbonate (DMC) was used as a green chemistry reagent instead of the traditional harmful methylation reagents, in accordance with the current concept of green chemistry. The phase transfer catalyst (PTC) polyethylene glycol 800 (PEG-800) was introduced into the isomerization reaction to break the barrier of difficult contact between solid and liquid phases and drastically reduce the reaction conditions by shortening the reaction time and reducing the alkalinity of the reaction system. The catalytic systems for the one-step green synthesis of IEME were screened, and it was shown that the catalytic system "K2CO3 + PEG-800" was the most effective. The effects of reaction temperature, n(DMC):n(eugenol) ratio, n(PEG-800):n(eugenol) ratio, and n(K2CO3):n(eugenol) ratio on eugenol conversion, IEME yield, and IEME selectivity were investigated. The results showed that the best reaction was achieved at a reaction temperature of 140 °C, a reaction time of 3 h, a DMC drip rate of 0.09 mL/min, and n(eugenol):n(DMC):n(K2CO3):n(PEG-800) = 1:3:0.09:0.08. As a result of the conversion of 93.1% of eugenol to IEME, a yield of 86.1% IEME as well as 91.6% IEME selectivity were obtained.
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Affiliation(s)
| | | | | | | | | | | | - Zhiqiang Hu
- College of Pharmacy and Chemistry & Chemical Engineering, Taizhou University, 93 Ji Chuan Road, Taizhou 225300, China; (Z.Z.); (X.X.); (M.Z.)
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Zhao J, Xu G, Wang X, Liu J, Ren X, Hong X, Lu Z. Cobalt-Catalyzed Migration Isomerization of Dienes. Org Lett 2022; 24:4592-4597. [PMID: 35727697 DOI: 10.1021/acs.orglett.2c01701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A cobalt-catalyzed multipositional isomerization of conjugated dienes has been reported for the first time using an 8-oxazoline iminoquinoline ligand. This reaction is operationally simple and atom-economical using readily available starting materials with an E/Z mixture to access disubstituted 1,3-dienes with excellent yields and good E,E stereoselectivity. The mechanism via alkene insertion of cobalt hydride species and β-H elimination of a π-allyl cobalt intermediate is proposed on the basis of deuterium labeling and control experiments and density functional theory calculations.
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Affiliation(s)
- Jiajin Zhao
- Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Guoxiong Xu
- Department of Chemistry, Zhejiang University, Hangzhou 310058, China.,Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.,State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.,Beijing National Laboratory for Molecular Sciences, Zhongguancun North First Street NO. 2, Beijing 100190, P.R. China.,Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Xue Wang
- Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Jiren Liu
- Department of Chemistry, Zhejiang University, Hangzhou 310058, China.,Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.,State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.,Beijing National Laboratory for Molecular Sciences, Zhongguancun North First Street NO. 2, Beijing 100190, P.R. China.,Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Xiang Ren
- Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Xin Hong
- Department of Chemistry, Zhejiang University, Hangzhou 310058, China.,Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.,State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.,Beijing National Laboratory for Molecular Sciences, Zhongguancun North First Street NO. 2, Beijing 100190, P.R. China.,Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Zhan Lu
- Department of Chemistry, Zhejiang University, Hangzhou 310058, China.,Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.,College of Chemistry, Zhengzhou University, Zhengzhou 450001, China
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3
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Jia Z, Zhang L, Luo S. Asymmetric C-H Dehydrogenative Allylic Alkylation by Ternary Photoredox-Cobalt-Chiral Primary Amine Catalysis under Visible Light. J Am Chem Soc 2022; 144:10705-10710. [PMID: 35674475 DOI: 10.1021/jacs.2c03299] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We report herein an asymmetric C-H dehydrogenative allylic alkylation by a synergistic catalytic system involving a chiral primary amine, a photoredox catalyst, and a cobaloxime cocatalyst. The ternary catalytic system enables the coupling of β-ketocarbonyls and olefins with good yields and high enantioselectivities. Mechanism studies disclosed a cooperative radical addition process with a chiral α-imino radical and Co(II)-metalloradical wherein the chiral primary aminocatalyst and the cobaloxime catalyst work in concert to control the stereoinduction.
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Affiliation(s)
- Zongbin Jia
- Key Laboratory for Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China, 100190
| | - Long Zhang
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing, China, 100084
| | - Sanzhong Luo
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing, China, 100084
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4
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Wang W, He S, Zhong Y, Chen J, Cai C, Luo Y, Xia Y. Cobalt-Catalyzed Z to E Geometrical Isomerization of 1,3-Dienes. J Org Chem 2022; 87:4712-4723. [PMID: 35275485 DOI: 10.1021/acs.joc.1c03164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
An efficient cobalt-catalyzed geometrical isomerization of 1,3-dienes is described. In the combination of a CoCl2 precatalyst with an amido-diphosphine-oxazoline ligand, the geometrical isomerization of E/Z mixtures of 1,3-dienes proceed in a stereoconvergent manner, affording (E) isomers in high stereoselectivity. This facile transformation features a broad substrate scope with good functional group tolerance and could be scaled up to the gram scale smoothly with a catalyst loading of 1 mol %.
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Affiliation(s)
- Wei Wang
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Shuying He
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Yuqing Zhong
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Jianhui Chen
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Cheng Cai
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Yanshu Luo
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Yuanzhi Xia
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
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Liu W, Zheng Y, Mao Y, Chen J, Ren X, Cheng Z, Lu Z. Desymmetrizing Isomerization of Alkene via Thiazolinyl Iminoquinoline Cobalt Catalysis. Org Lett 2022; 24:1158-1163. [PMID: 35089045 DOI: 10.1021/acs.orglett.1c04237] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We report a cobalt-catalyzed desymmetrizing isomerization of exo-cyclic alkenes to generate chiral 1-methylcyclohexene derivatives with good yields and enantioselectivities. A novel chiral thiazolinyl iminoquinoline ligand and its cobalt complex were designed and synthesized to control the establishment of tertiary or quaternary carbon centers at a remote position. This protocol is operationally simple, and a model for the stereochemical outcome has been proposed.
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Affiliation(s)
- Wenbo Liu
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Yushan Zheng
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Yihui Mao
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Jieping Chen
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Xiang Ren
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Zhaoyang Cheng
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Zhan Lu
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.,College of Chemistry, Zhengzhou University, Zhengzhou 450001, China
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