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Awasthi A, Tiwari K, Tiwari DK. Tf 2O-mediated [4+2]-annulation of anthranils with 2-chloropyridines: enabling access to pyridoquinazolinones and euxylophoricine B. Chem Commun (Camb) 2024; 60:7749-7752. [PMID: 38973615 DOI: 10.1039/d4cc01821d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
We present an efficient approach for synthesizing pyridoquinazolinones in the presence of triflic anhydride utilizing anthranils and 2-chloropyridines as starting materials. In this process, Tf2O initially activates anthranils forming an electrophilic 1-((trifluoromethyl)sulfonyl)benzo[c]isoxazol-1-ium species. This species undergoes an in situ annulation reaction with 2-chloropyridines, resulting in therapeutically useful pyridoquinazolinones. The reaction is tolerant to various functional groups, allowing access to a wide range of substituted pyridoquinazolinones in good yields. Furthermore, the synthesis of euxylophoricine B, known to be an antitumor agent, was also achieved.
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Affiliation(s)
- Annapurna Awasthi
- Department of Biological and Synthetic Chemistry, Center of Biomedical Research (CBMR), SGPGIMS Campus, Raibareli Road, Lucknow, UP 226014, India.
- Department of Chemistry, Institute of Science, Banaras Hindu Universiy, 221005, UP, India
| | - Khushboo Tiwari
- Department of Biological and Synthetic Chemistry, Center of Biomedical Research (CBMR), SGPGIMS Campus, Raibareli Road, Lucknow, UP 226014, India.
- Academy of Scientific & Innovative Research (AcSIR), CSIR- Human Resource Development Centre, (CSIR-HRDC) Campus Ghaziabad, Uttar Pradesh-201 002, India
| | - Dharmendra Kumar Tiwari
- Department of Biological and Synthetic Chemistry, Center of Biomedical Research (CBMR), SGPGIMS Campus, Raibareli Road, Lucknow, UP 226014, India.
- Academy of Scientific & Innovative Research (AcSIR), CSIR- Human Resource Development Centre, (CSIR-HRDC) Campus Ghaziabad, Uttar Pradesh-201 002, India
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Awasthi A, Tiwari K, Yadav P, Bhowmick S, Tiwari DK. Synthesis of 4-styrylquinolines via direct oxidative C3-alkenylation of anthranils under Pd(II) catalysis. Chem Commun (Camb) 2024; 60:2054-2057. [PMID: 38288529 DOI: 10.1039/d3cc05790a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
The palladium-catalyzed oxidative C3-alkenylation of anthranils (2,1-benzisoxazoles) with various styrenes has been successfully achieved. The C3-alkenylated anthranils were subsequently utilized in a [4+2]-cycloaddition with in situ generated α,β-unsaturated ketones leading to the synthesis of a diverse range of olefin-containing quinolines. Notably, this reaction exclusively yielded mono-alkenylated products with E-selectivity. The optimized catalytic conditions were compatible with a wide variety of substituted olefins and anthranils, forming various C3-alkenylated anthranils with good yields. To showcase the application of the present methodology, the C3-alkenylated anthranils have been employed as synthons to access a wide range of substituted quinolines.
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Affiliation(s)
- Annapurna Awasthi
- Department of Biological and Synthetic Chemistry, Center of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India. dktiwari.@cbmr.res.in
- Department of Chemistry, Institute of Science, Banaras Hindu University, 221005, Varanasi, Uttar Pradesh, India
| | - Khushboo Tiwari
- Department of Biological and Synthetic Chemistry, Center of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India. dktiwari.@cbmr.res.in
| | - Pushpendra Yadav
- Department of Biological and Synthetic Chemistry, Center of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India. dktiwari.@cbmr.res.in
- Department of Chemistry, Institute of Science, Banaras Hindu University, 221005, Varanasi, Uttar Pradesh, India
| | - Suman Bhowmick
- Department of Biological and Synthetic Chemistry, Center of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India. dktiwari.@cbmr.res.in
| | - Dharmendra Kumar Tiwari
- Department of Biological and Synthetic Chemistry, Center of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India. dktiwari.@cbmr.res.in
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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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Li S, Xu X, Sun Q, Xu X. Organocalcium Hydride-Catalyzed Intramolecular C(sp 3)-H Annulation of Functionalized 2,6-Lutidines. J Org Chem 2023; 88:1742-1748. [PMID: 36645347 DOI: 10.1021/acs.joc.2c02800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
This work reports an intramolecular C(sp3)-H annulation of functionalized 2,6-lutidines catalyzed by an organocalcium hydride [{(DIPPnacnac)CaH(thf)}2] (DIPPnacnac = CH{(CMe)(2,6-iPr2-C6H3N)}2). This reaction constitutes a streamlined approach for producing a new family of tetrahydro-1,5-naphthyridines and hexahydropyrido[3,2-b]azocines derivatives in good to excellent yields with high atom efficiency and broad substrates scope. A calcium alkyl complex was isolated from the stoichiometric reaction between calcium hydride and the substrate through deprotonation, which was structurally characterized and confirmed as the catalytic intermediate.
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Affiliation(s)
- Shuo Li
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Xian Xu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Qianlin Sun
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Xin Xu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
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Chen Z, Yan K, Luo H, Yan J, Zeng Y. Lewis acid-catalyzed [4 + 2] cycloaddition of donor–acceptor cyclobutanes with iminooxindoles: access to spiro[piperidine-3,2′-oxindoles]. RSC Adv 2022; 12:32097-32101. [DOI: 10.1039/d2ra04730f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/27/2022] [Indexed: 11/10/2022] Open
Abstract
A Lewis acid-catalyzed [4 + 2] cycloaddition reaction from D–A cyclobutanes and iminooxindoles, providing the corresponding spiro[piperidine-3,2′-oxindoles] under mild conditions.
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Affiliation(s)
- Zuliang Chen
- College of Chemistry and Bio-engineering, Yichun University, Yichun 336000, P. R. China
- Key Laboratory of Jiangxi University for Applied Chenistry and Chemical Biology, Yichun University, 336000, P. R. China
| | - Keyi Yan
- College of Chemistry and Bio-engineering, Yichun University, Yichun 336000, P. R. China
| | - Hui Luo
- College of Chemistry and Bio-engineering, Yichun University, Yichun 336000, P. R. China
| | - Jun Yan
- College of Chemistry and Bio-engineering, Yichun University, Yichun 336000, P. R. China
| | - Yang Zeng
- College of Chemistry and Bio-engineering, Yichun University, Yichun 336000, P. R. China
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