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Jin HS, Zhu T. Synthesis of Benzofuran-Fused Oxepines through Cs 2CO 3-Promoted [4 + 3] Annulation of Aurones with Crotonate-Derived Sulfonium Salts. J Org Chem 2024; 89:3271-3278. [PMID: 38332626 DOI: 10.1021/acs.joc.3c02715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Benzofuran-fused derivatives display important and reliable therapeutic properties. Herein, we describe the synthesis of benzofuran-fused oxepines using aurones and crotonate-derived sulfonium salts via a [4 + 3] annulation reaction in the presence of Cs2CO3. This reaction proceeds under mild and operationally simple conditions. The synthetic utility of this approach was highlighted by several transformations, including the efficient synthesis of a novel tetracyclic fused benzofuran derivative.
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Affiliation(s)
- Hai-Shan Jin
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, Jiangsu, China
| | - Tong Zhu
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, Jiangsu, China
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2
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Wang Y, Jin Z, Zhou L, Lv X. Recent advances in [4 + 4] annulation of conjugated heterodienes with 1,4-dipolar species for the synthesis of eight-membered heterocycles. Org Biomol Chem 2024; 22:252-268. [PMID: 38062977 DOI: 10.1039/d3ob01626a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Numerous eight-membered heterocycles are of significance in biological chemistry, the pharmaceutical industry, agrochemistry, and materials science. However, the assembly of eight-membered heterocycles is usually challenging due to the unfavorable enthalpic and entropic barriers of the transition states during the ring formation. Tremendous efforts have been devoted to the development of synthetic routes to eight-membered heterocycles. Despite these developments, the exploration of more strategies for the facile and effective assembly of eight-membered heterocyclic molecules in a single vessel under mild conditions is still highly desirable. The conjugated heterodiene-participating [4 + 4] annulation serves as a convenient and robust strategy for the synthesis of eight-membered heterocycles from easily accessible starting materials. In recent years, great progress has been achieved in this attractive field. In this short review, we highlighted the recent advances in the synthesis of eight-membered heterocycles via cascade reactions based on [4 + 4] annulation of conjugated heterodienes with 1,4-dipolar species. The brief backgrounds, the general reactions, the proposed mechanisms and their features are summarized. The prospects and challenges of this field are also outlined at the end of this review. In addition, to highlight the importance and practicality of these reactions, the properties of several series of eight-membered heterocycles have also been introduced briefly.
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Affiliation(s)
- Yahui Wang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, 688 Yinbing Rd, Jinhua 321004, People's Republic of China.
| | - Zefeng Jin
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, 688 Yinbing Rd, Jinhua 321004, People's Republic of China.
| | - Liejin Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, 688 Yinbing Rd, Jinhua 321004, People's Republic of China.
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Xin Lv
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, 688 Yinbing Rd, Jinhua 321004, People's Republic of China.
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Khuntia R, Mahapatra SK, Roy L, Chandra Pan S. Structurally divergent enantioselective synthesis of benzofuran fused azocine derivatives and spiro-cyclopentanone benzofurans enabled by sequential catalysis. Chem Sci 2023; 14:10768-10776. [PMID: 37829006 PMCID: PMC10566461 DOI: 10.1039/d3sc03239f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 09/04/2023] [Indexed: 10/14/2023] Open
Abstract
An important objective in organic synthesis and medicinal chemistry is the capacity to access structurally varied and complex molecules rapidly and affordably from easily available starting materials. Herein, a protocol for the structurally divergent synthesis of benzofuran fused azocine derivatives and spiro-cyclopentanone benzofurans has been developed via chiral bifunctional urea catalyzed reaction between aurone-derived α,β-unsaturated imine and ynone followed by switchable divergent annulation reactions by Lewis base catalysts (DBU and PPh3) with concomitant epimerization. The skeletally diversified products were formed in high yields with high diastereo- and enantioselectivities. Computational analysis with DFT and accurate DLPNO-CCSD(T) has been employed to gain deeper insights into mechanistic intricacies and investigate the role of chiral and Lewis base catalysts in skeletal diversity.
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Affiliation(s)
- Rupkumar Khuntia
- Department of Chemistry, Indian Institute of Technology Guwahati Assam 781039 India https://www.iitg.ac.in/span/
| | - Sanat Kumar Mahapatra
- Institute of Chemical Technology Mumbai IOC Odisha Campus Bhubaneswar Bhubaneswar 751013 India
| | - Lisa Roy
- Institute of Chemical Technology Mumbai IOC Odisha Campus Bhubaneswar Bhubaneswar 751013 India
| | - Subhas Chandra Pan
- Department of Chemistry, Indian Institute of Technology Guwahati Assam 781039 India https://www.iitg.ac.in/span/
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Zhang B, Jin Z, Huang C, Zhang Y, Shen G, Kang H, Lv X, Zhou L. Highly Diastereoselective One-Pot Synthesis of 4,5-Dihydrofuro[2,3- b]azocin-6-one Derivatives through Cyclization/[4+4] Annulation Reactions. J Org Chem 2023. [PMID: 37155326 DOI: 10.1021/acs.joc.3c00003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A variety of 4,5-dihydrofuro[2,3-b]azocin-6-one derivatives were expediently assembled through Au(I)-catalyzed cyclization and 2-(tert-butyl)-1,1,3,3-tetramethylguanidine (BTMG)-mediated [4+4] annulation reactions of enyne-amides and ynones. The reactions exhibit high efficiency with excellent regio- and diastereoselectivity. A broad spectrum of substrates was utilized. The products with an eight-membered ring might be useful in biological chemistry and medicinal science. Furthermore, the products could be facilely converted into various derivatives.
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Affiliation(s)
- Bei Zhang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Zefeng Jin
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Chaoman Huang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Yankun Zhang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Guodong Shen
- School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Liaocheng University, Liaocheng 252059, Shandong, People's Republic of China
| | - Honglan Kang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Xin Lv
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Liejin Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, People's Republic of China
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5
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Li Y, Cheng S, Tian Y, Zhang Y, Zhao Y. Recent ring distortion reactions for diversifying complex natural products. Nat Prod Rep 2022; 39:1970-1992. [PMID: 35972343 DOI: 10.1039/d2np00027j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: 2013-2022.Chemical diversification of natural products is an efficient way to generate natural product-like compounds for modern drug discovery programs. Utilizing ring-distortion reactions for diversifying natural products would directly alter the core ring systems of small molecules and lead to the production of structurally complex and diverse compounds for high-throughput screening. We review the ring distortion reactions recently used in complexity-to-diversity (CtD) and pseudo natural products (pseudo-NPs) strategies for diversifying complex natural products. The core ring structures of natural products are altered via ring expansion, ring cleavage, ring edge-fusion, ring spiro-fusion, ring rearrangement, and ring contraction. These reactions can rapidly provide natural product-like collections with properties suitable for a wide variety of biological and medicinal applications. The challenges and limitations of current ring distortion reactions are critically assessed, and avenues for future improvements of this rapidly expanding field are discussed. We also provide a toolbox for chemists for the application of ring distortion reactions to access natural product-like molecules.
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Affiliation(s)
- Yu Li
- School of Pharmacy, Nantong University, Nantong 226001, China.
| | - Shihao Cheng
- School of Pharmacy, Nantong University, Nantong 226001, China.
| | - Yun Tian
- School of Pharmacy, Nantong University, Nantong 226001, China.
| | - Yanan Zhang
- School of Pharmacy, Nantong University, Nantong 226001, China.
| | - Yu Zhao
- School of Pharmacy, Nantong University, Nantong 226001, China.
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Tu L, Gao L, Wang Q, Cao Z, Huang R, Zheng Y, Liu J. Substrate-Switched Chemodivergent Pyrazole and Pyrazoline Synthesis: [3 + 2] Cycloaddition/Ring-Opening Rearrangement Reaction of Azadienes with Nitrile Imines. J Org Chem 2022; 87:3389-3401. [PMID: 35157462 DOI: 10.1021/acs.joc.1c02998] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
By virtue of a fundamentally new reaction model of benzofuran-derived azadienes (BDAs), an unprecedented synthesis of biologically important pyrazoles has been achieved through a tandem [3 + 2] cycloaddition/ring-opening rearrangement reaction of BDAs with nitrile imines. The nature and type of substrates are found to act as a chemical switch to trigger two distinct reaction pathways. A minor modification to the substrates allows the access to spiro-pyrazolines.
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Affiliation(s)
- Liang Tu
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Limei Gao
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Qiang Wang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Zhixing Cao
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Rong Huang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Yongsheng Zheng
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan 430074, China.,National Demonstration Center for Experimental Ethnopharmacology Education, South-Central University for Nationalities, Wuhan 430074, China
| | - Jikai Liu
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan 430074, China
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7
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Zhang B, Yang H, Wang T, Han X, Sun H, Fang L, Zhai H, Cheng B. Synthesis of 5 H-Chromeno[2,3- d]pyrimidin-5-one Derivatives via Microwave-Promoted Multicomponent Reaction. J Org Chem 2021; 86:18304-18311. [PMID: 34813338 DOI: 10.1021/acs.joc.1c02434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A microwave-promoted multicomponent reaction of 3-formylchromones, amines, and paraformaldehyde was achieved under catalyst-free and solvent-free conditions, delivering 5H-chromeno[2,3-d]pyrimidin-5-one derivatives in good to excellent yields via an unexpected annulation pathway, which further expanded the synthetic application of paraformaldehyde as a C1 building block.
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Affiliation(s)
- Biwei Zhang
- Institute of Marine Biomedicine/Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Hongjian Yang
- State Key Laboratory of Chemical Oncogenomics, Shenzhen Engineering Laboratory of Nano Drug Slow-Release, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Taimin Wang
- Institute of Marine Biomedicine/Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Xuanzhen Han
- Institute of Marine Biomedicine/Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Haiyan Sun
- Institute of Marine Biomedicine/Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Lijing Fang
- Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Hongbin Zhai
- State Key Laboratory of Chemical Oncogenomics, Shenzhen Engineering Laboratory of Nano Drug Slow-Release, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Bin Cheng
- Institute of Marine Biomedicine/Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, Shenzhen 518055, China
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