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Betcke I, Götzinger AC, Kornet MM, Müller TJJ. Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps. Beilstein J Org Chem 2024; 20:2024-2077. [PMID: 39161713 PMCID: PMC11331544 DOI: 10.3762/bjoc.20.178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 07/19/2024] [Indexed: 08/21/2024] Open
Abstract
Pyrazoles are rarely found in nature but are traditionally used in the agrochemical and pharmaceutical industries, while other areas of use are also actively developing. However, they have also found numerous other applications. The search for new and efficient syntheses of these heterocycles is therefore highly relevant. The modular concept of multicomponent reactions (MCR) has paved a broad alley to heteroaromatics. The advantages over traditional methods are the broader scope and increased efficiency of these reactions. In particular, traditional multistep syntheses of pyrazoles have considerably been extended by MCR. Progress has been made in the cyclocondensation of 1,3-dielectrophiles that are generated in situ. Limitations in the regioselectivity of cyclocondensation with 1,3-dicarbonyls were overcome by the addition-cyclocondensation of α,β-unsaturated ketones. Embedding 1,3-dipolar cycloadditions into a one-pot process has additionally been developed for concise syntheses of pyrazoles. The MCR strategy also allows for concatenating classical condensation-based methodology with modern cross-coupling and radical chemistry, as well as providing versatile synthetic approaches to pyrazoles. This overview summarizes the most important MCR syntheses of pyrazoles based on ring-forming sequences in a flashlight fashion.
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Affiliation(s)
- Ignaz Betcke
- Heinrich-Heine-Universität Düsseldorf, Math.-Nat. Fakultät, Institut für Organische Chemie und Makromolekulare Chemie, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
| | - Alissa C Götzinger
- Heinrich-Heine-Universität Düsseldorf, Math.-Nat. Fakultät, Institut für Organische Chemie und Makromolekulare Chemie, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
| | - Maryna M Kornet
- Heinrich-Heine-Universität Düsseldorf, Math.-Nat. Fakultät, Institut für Organische Chemie und Makromolekulare Chemie, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
- Zaporizhzhia National University, Faculty of Biology, Department of Chemistry, Zhukovskogo Street 66, 69600 Zaporizhzhia, Ukraine
| | - Thomas J J Müller
- Heinrich-Heine-Universität Düsseldorf, Math.-Nat. Fakultät, Institut für Organische Chemie und Makromolekulare Chemie, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
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2
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Bhaskaran RP, Sreelekha MK, Babu BP. Metal‐free Synthesis of Trisubstituted Pyrazoles by the Reaction Between Hydrazones and Activated Olefins. ChemistrySelect 2022. [DOI: 10.1002/slct.202202773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Rasmi P. Bhaskaran
- Department of Chemistry National Institute of Technology Karnataka Surathkal Mangalore INDIA – 575025
| | - Mariswamy K. Sreelekha
- Department of Chemistry National Institute of Technology Karnataka Surathkal Mangalore INDIA – 575025
| | - Beneesh P. Babu
- Department of Chemistry National Institute of Technology Karnataka Surathkal Mangalore INDIA – 575025
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3
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Wang Q, Hong G, Tang Z, Yang P, Zhong Y, Gong Y, Wang L. Divergent Synthesis of 3,5‐disubstituted Pyrazoles and α, β‐alkynic hydrazone from Diarylpropynones and Carbazates. ASIAN J ORG CHEM 2021. [DOI: 10.1002/ajoc.202100794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Qi Wang
- East China University of Science and Technology School of Chemistry and Molecular Engineering School of Chemistry and Molecular Engineering CHINA
| | - Gang Hong
- East China University of Science and Technology School of Chemistry and Molecular Engineering School of Chemistry and Molecular Engineering CHINA
| | - Zhicong Tang
- East China University of Science and Technology School of Chemistry and Molecular Engineering School of Chemistry and Molecular Engineering CHINA
| | - Peng Yang
- East China University of Science and Technology School of Chemistry and Molecular Engineering School of Chemistry and Molecular Engineering CHINA
| | - Yi Zhong
- East China University of Science and Technology School of Chemistry and Molecular Engineering School of Chemistry and Molecular Engineering CHINA
| | - Yu Gong
- East China University of Science and Technology School of Chemistry and Molecular Engineering School of Chemistry and Molecular Engineering CHINA
| | - Limin Wang
- East China University of Science and Technology School of Chemical and Molecular Engineering 130 Meilong Road 200237 Shanghai CHINA
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4
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One‐pot Synthesis of Substituted Pyrazoles from Propargyl Alcohols via Cyclocondensation of in situ‐Generated α‐Iodo Enones/Enals and Hydrazine Hydrate. ASIAN J ORG CHEM 2021. [DOI: 10.1002/ajoc.202100318] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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5
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Wei Z, Zhang Q, Tang M, Zhang S, Zhang Q. Diversity-Oriented Synthesis of 1,2,4-Triazols, 1,3,4-Thiadiazols, and 1,3,4-Selenadiazoles from N-Tosylhydrazones. Org Lett 2021; 23:4436-4440. [PMID: 33988376 DOI: 10.1021/acs.orglett.1c01379] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The diversity-oriented synthesis of 1,2,4-triazols, 1,3,4-thiadiazols, and 1,3,4-selenadiazoles from N-tosylhydrazones was developed, and the reactions were general for a wide range of substrates, in which NH2CN, KOCN, KSCN, and KSeCN were used as odorless sources. Two different pathways were proposed, and N-tosylhydrazonoyl chlorides were formed in situ in the presence of NCS.
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Affiliation(s)
- Zeyang Wei
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Qi Zhang
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Meng Tang
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Siyu Zhang
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Qian Zhang
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
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6
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Pyrazole Scaffold Synthesis, Functionalization, and Applications in Alzheimer's Disease and Parkinson's Disease Treatment (2011-2020). Molecules 2021; 26:molecules26051202. [PMID: 33668128 PMCID: PMC7956461 DOI: 10.3390/molecules26051202] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/20/2021] [Accepted: 02/22/2021] [Indexed: 11/17/2022] Open
Abstract
The remarkable prevalence of pyrazole scaffolds in a versatile array of bioactive molecules ranging from apixaban, an anticoagulant used to treat and prevent blood clots and stroke, to bixafen, a pyrazole-carboxamide fungicide used to control diseases of rapeseed and cereal plants, has encouraged both medicinal and organic chemists to explore new methods in developing pyrazole-containing compounds for different applications. Although numerous synthetic strategies have been developed in the last 10 years, there has not been a comprehensive overview of synthesis and the implication of recent advances for treating neurodegenerative disease. This review first presents the advances in pyrazole scaffold synthesis and their functionalization that have been published during the last decade (2011-2020). We then narrow the focus to the application of these strategies in the development of therapeutics for neurodegenerative diseases, particularly for Alzheimer's disease (AD) and Parkinson's disease (PD).
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Ma L, Ou P, Huang X. Divergent synthesis of 1,3,5-tri and 1,3-disubstituted pyrazoles under transition metal-free conditions. Org Biomol Chem 2020; 18:6487-6491. [PMID: 32785327 DOI: 10.1039/d0ob01478h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pyrazole cores are common structural motifs existing in various agrochemicals and pharmaceuticals. Herein, a transition metal-free, three-component reaction of arylaldehydes, ethyl acrylate and N-tosylhydrazones is described, which leads to the formation of 1,3,5-trisubstituted and 1,3-disubstituted pyrazoles divergently under slightly different conditions.
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Affiliation(s)
- Liyao Ma
- College of Chemistry, Fuzhou University, Fuzhou 350116, China and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Fujian College, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
| | - Pengcheng Ou
- College of Chemistry, Fuzhou University, Fuzhou 350116, China and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Fujian College, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
| | - Xueliang Huang
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Fujian College, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
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8
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Zhang Q, Tang M, Zhang S, Wei Z. Acid-Promoted [3 + 1 + 1] Cyclization of N-Tosylhydrazones and Isocyanides: A Method for the Preparation of 4,5-Diaminopyrazoles. Org Lett 2020; 22:5182-5186. [DOI: 10.1021/acs.orglett.0c01809] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Qian Zhang
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Meng Tang
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Siyu Zhang
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Zeyang Wei
- School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
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9
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Metal-free and highly regioselective synthesis of N-heteroaryl substituted pyrazoles from α,β-unsaturated N-tosylhydrazones and heteroaryl chlorides. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2019.07.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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10
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Zhang Q, Tang M. Regioselective Synthesis of Highly Functionalized Pyrazoles from N-Tosylhydrazones. Org Lett 2019; 21:1917-1920. [PMID: 30829036 DOI: 10.1021/acs.orglett.9b00561] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A regioselective synthesis of highly functionalized pyrazoles from N-tosylhydrazones was developed. The reaction was general for a wide range of substrates and demonstrated excellent tolerance to a variety of substituents, and the method has been successfully applied to the formal synthesis of ibrutinib.
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Affiliation(s)
- Qian Zhang
- School of Pharmacy , Lanzhou University , Lanzhou 730000 , P.R. China
| | - Meng Tang
- School of Pharmacy , Lanzhou University , Lanzhou 730000 , P.R. China
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11
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Remy R, Bochet CG. Application of Photoclick Chemistry for the Synthesis of Pyrazoles via 1,3-Dipolar Cycloaddition between Alkynes and Nitrilimines Generated In Situ. European J Org Chem 2018. [DOI: 10.1002/ejoc.201701225] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Richard Remy
- Department of Chemistry; University of Fribourg; Chemin du Musée 9 CH-1700 Fribourg Switzerland
| | - Christian G. Bochet
- Department of Chemistry; University of Fribourg; Chemin du Musée 9 CH-1700 Fribourg Switzerland
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12
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Xia Y, Wang J. N-Tosylhydrazones: versatile synthons in the construction of cyclic compounds. Chem Soc Rev 2017; 46:2306-2362. [DOI: 10.1039/c6cs00737f] [Citation(s) in RCA: 214] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
N-Tosylhydrazones have been extensively explored as versatile building blocks in the construction of various cyclic compounds.
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Affiliation(s)
- Ying Xia
- Beijing National Laboratory of Molecular Sciences (BNLMS)
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education
- College of Chemistry
- Peking University
- Beijing 100871
| | - Jianbo Wang
- Beijing National Laboratory of Molecular Sciences (BNLMS)
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education
- College of Chemistry
- Peking University
- Beijing 100871
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13
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Kiyokawa K, Ito Y, Kakehi R, Ogawa T, Goto Y, Yoshimatsu M. Propargyl Hydrazides as Useful Intermediates Leading to Pyrazoles via Reaction with Certain Electrophiles. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600708] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Kosuke Kiyokawa
- Department of Chemistry; Faculty of Education; Gifu University; Yanagido 1-1 501-1193 Gifu Japan
| | - Yukiteru Ito
- Department of Chemistry; Faculty of Education; Gifu University; Yanagido 1-1 501-1193 Gifu Japan
| | - Ryoma Kakehi
- Department of Chemistry; Faculty of Education; Gifu University; Yanagido 1-1 501-1193 Gifu Japan
| | - Takahiro Ogawa
- Department of Chemistry; Faculty of Education; Gifu University; Yanagido 1-1 501-1193 Gifu Japan
| | - Yusuke Goto
- Department of Chemistry; Faculty of Education; Gifu University; Yanagido 1-1 501-1193 Gifu Japan
| | - Mitsuhiro Yoshimatsu
- Department of Chemistry; Faculty of Education; Gifu University; Yanagido 1-1 501-1193 Gifu Japan
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14
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Keiko NA, Vchislo NV. Synthesis of Diheteroatomic Five-Membered Heterocyclic Compounds from α,β-Unsaturated Aldehydes. ASIAN J ORG CHEM 2016. [DOI: 10.1002/ajoc.201600227] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- N. A. Keiko
- A. E. Favorsky Irkutsk Institute of Chemistry; Siberian Branch of the Russian Academy of Sciences; 1 Favorsky Street 664033 Irkutsk Russian Federation
| | - N. V. Vchislo
- A. E. Favorsky Irkutsk Institute of Chemistry; Siberian Branch of the Russian Academy of Sciences; 1 Favorsky Street 664033 Irkutsk Russian Federation
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15
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Gonçalves HA, Pereira BA, Teixeira WK, Moura S, Flores DC, Flores AF. Synthesis of 2,2,2-trifluoroethyl 1H-pyrazole carboxylates: Insight into the mechanism of trichloromethyl group hydrolysis. J Fluor Chem 2016. [DOI: 10.1016/j.jfluchem.2016.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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16
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Nemati F, Nikkhah SH, Elhampour A. An environmental friendly approach for the catalyst-free synthesis of highly substituted pyrazoles promoted by ultrasonic radiation. CHINESE CHEM LETT 2015. [DOI: 10.1016/j.cclet.2015.07.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Fandrick DR, Sanyal S, Kaloko J, Mulder JA, Wang Y, Wu L, Lee H, Roschangar F, Hoffmann M, Senanayake CH. A Michael Equilibration Model To Control Site Selectivity in the Condensation toward Aminopyrazoles. Org Lett 2015; 17:2964-7. [DOI: 10.1021/acs.orglett.5b01248] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel R. Fandrick
- Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, P.O. Box 368, Ridgefield, Connecticut 06877-0368, United States
| | - Sanjit Sanyal
- Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, P.O. Box 368, Ridgefield, Connecticut 06877-0368, United States
| | - Joseph Kaloko
- Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, P.O. Box 368, Ridgefield, Connecticut 06877-0368, United States
| | - Jason A. Mulder
- Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, P.O. Box 368, Ridgefield, Connecticut 06877-0368, United States
| | - Yuwen Wang
- Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, P.O. Box 368, Ridgefield, Connecticut 06877-0368, United States
| | - Ling Wu
- Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, P.O. Box 368, Ridgefield, Connecticut 06877-0368, United States
| | - Heewon Lee
- Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, P.O. Box 368, Ridgefield, Connecticut 06877-0368, United States
| | - Frank Roschangar
- Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, P.O. Box 368, Ridgefield, Connecticut 06877-0368, United States
| | - Matthias Hoffmann
- Department of Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Strasse 65, Biberach an der Riss 88397, Germany
| | - Chris H. Senanayake
- Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, P.O. Box 368, Ridgefield, Connecticut 06877-0368, United States
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Ding Z, Tan Q, Gao M, Xu B. Copper-catalyzed aerobic cascade cycloamination and acyloxylation: a direct approach to 4-acyloxy-1H-pyrazoles. Org Biomol Chem 2015; 13:4642-6. [DOI: 10.1039/c5ob00409h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient copper-catalyzed regioselective olefinic C(sp2)–H bond cycloamination and acyloxylation was developed to give acyloxylated pyrazoles under mild conditions, which combines the formation of the pyrazole skeleton and installation of an acyloxyl group in a single step.
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Affiliation(s)
- Zhengwei Ding
- Department of Chemistry
- Innovative Drug Research Center
- Shanghai University
- Shanghai 200444
- China
| | - Qitao Tan
- Department of Chemistry
- Innovative Drug Research Center
- Shanghai University
- Shanghai 200444
- China
| | - Mingchun Gao
- Department of Chemistry
- Innovative Drug Research Center
- Shanghai University
- Shanghai 200444
- China
| | - Bin Xu
- Department of Chemistry
- Innovative Drug Research Center
- Shanghai University
- Shanghai 200444
- China
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19
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Patil D, Chandam D, Mulik A, Jagdale S, Patil P, Deshmukh M. Novel crown ether functionalized imidazolium-based acidic ionic liquid catalyzed synthesis of pyrazole derivatives under solvent-free conditions. RESEARCH ON CHEMICAL INTERMEDIATES 2014. [DOI: 10.1007/s11164-014-1782-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Harigae R, Moriyama K, Togo H. Preparation of 3,5-disubstituted pyrazoles and isoxazoles from terminal alkynes, aldehydes, hydrazines, and hydroxylamine. J Org Chem 2014; 79:2049-58. [PMID: 24512630 DOI: 10.1021/jo4027116] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The reaction of terminal alkynes with n-BuLi, and then with aldehydes, followed by the treatment with molecular iodine, and subsequently hydrazines or hydroxylamine provided the corresponding 3,5-disubstituted pyrazoles or isoxazoles in good yields with high regioselectivity, through the formations of propargyl secondary alkoxides and α-alkynyl ketones. The present reactions are one-pot preparation of 3,5-disubstituted pyrazoles from terminal alkynes, aldehydes, molecular iodine, and hydrazines, and 3,5-disubstituted isoxazoles from terminal alkynes, aldehydes, molecular iodine, and hydroxylamine.
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Affiliation(s)
- Ryo Harigae
- Graduate School of Science, Chiba University , Yayoi-cho 1-33, Inage-ku, Chiba 263-8522, Japan
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21
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Zhao J, Li P, Xia C, Li F. Direct N-acylation of azoles via a metal-free catalyzed oxidative cross-coupling strategy. Chem Commun (Camb) 2014; 50:4751-4. [DOI: 10.1039/c4cc01587h] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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22
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Kong Y, Tang M, Wang Y. Regioselective Synthesis of 1,3,5-Trisubstituted Pyrazoles from N-Alkylated Tosylhydrazones and Terminal Alkynes. Org Lett 2013; 16:576-9. [DOI: 10.1021/ol403447g] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Yuanfang Kong
- School
of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Meng Tang
- School
of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Yun Wang
- School
of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
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23
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Kong Y, Zhang W, Tang M, Wang H. N-Alkylation of tosylhydrazones in the presence of triphenylphosphine. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.05.131] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Tang M, Zhang W, Kong Y. DABCO-promoted synthesis of pyrazoles from tosylhydrazones and nitroalkenes. Org Biomol Chem 2013; 11:6250-4. [DOI: 10.1039/c3ob41435c] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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