51
|
Alizadeh A, Reza Esmaili zand H, Saberi V, Mokhtari J. Synthesis of 5-Aryl-3-(methylsulfanyl)-1H-pyrazolesviaThree-Component Reaction of 1,1-Bis(methylsulfanyl)-2-nitroethene, Aromatic Aldehydes, and Hydrazine. Helv Chim Acta 2013. [DOI: 10.1002/hlca.201300070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
52
|
Wang H, Zhao YL, Li L, Zhang ZW, Liu Q. Bicyclization of Diazomethanes: A Synthetic Strategy for Fused Pyrazoles. Adv Synth Catal 2013. [DOI: 10.1002/adsc.201201062] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
53
|
Kumar SV, Yadav SK, Raghava B, Saraiah B, Ila H, Rangappa KS, Hazra A. Cyclocondensation of arylhydrazines with 1,3-bis(het)arylmonothio-1,3-diketones and 1,3-bis(het)aryl-3-(methylthio)-2-propenones: synthesis of 1-aryl-3,5-bis(het)arylpyrazoles with complementary regioselectivity. J Org Chem 2013; 78:4960-73. [PMID: 23607788 DOI: 10.1021/jo400599e] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Two efficient highly regioselective routes for the synthesis of unsymmetrically substituted 1-aryl-3,5-bis(het)arylpyrazoles with complementary regioselectivity starting from active methylene ketones have been reported. In the first protocol, the newly synthesized 1,3-bis(het)aryl-monothio-1,3-diketone precursors (prepared by condensation of active methylene ketones with het(aryl) dithioesters in the presence of sodium hydride) were reacted with arylhydrazines in refluxing ethanol under neutral conditions, furnishing 1-aryl-3,5-bis(het)arylpyrazoles 7, in which the het(aryl) moiety attached to the thiocarbonyl group of monothio-1,3-diketones is installed at the 3-position. In the second method, the corresponding 3-(methylthio)-1,3-bis(het)aryl-2-propenones (prepared in situ by base-induced alkylation of 1,3-monothiodiketones) were condensed with arylhydrazines in the presence of potassium tert-butoxide in refluxing tert-butyl alcohol, yielding 1-aryl-3,5-bis(het)arylpyrazoles 9 with complementary regioselectivity (method A). The efficiency of this protocol was further improved by developing a one-pot, three-component procedure for the synthesis of pyrazoles 9, directly from active methylene ketones, by reacting in situ generated 3-(methylthio)-1,3-bis(het)aryl-2-propenones with arylhydrazines in the presence of sodium hydride (instead of potassium tert-butoxide as base). The structures and regiochemistry of newly synthesized pyrazoles were confirmed from their spectral and analytical data along with X-ray crystallographic data of three pairs of regioisomers.
Collapse
Affiliation(s)
- S Vijay Kumar
- New Chemistry unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560064, India
| | | | | | | | | | | | | |
Collapse
|
54
|
Cycloadditions and condensations as essential tools in spiropyrazoline synthesis. Eur J Med Chem 2013; 63:347-77. [DOI: 10.1016/j.ejmech.2013.01.059] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 01/12/2013] [Accepted: 01/15/2013] [Indexed: 11/17/2022]
|
55
|
Mohapatra S, Bhanja C, Jena S, Chakroborty S, Nayak S. Advances in the Bestmann–Ohira Reagent–Assisted Regioselective Synthesis of Substituted Pyrazoles, Triazoles, and Oxazoles. SYNTHETIC COMMUN 2013. [DOI: 10.1080/00397911.2012.711883] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Seetaram Mohapatra
- a Department of Chemistry , Ravenshaw University , Cuttack , Odisha , India
| | | | - Satyaban Jena
- b Department of Chemistry , Utkal University , Bhubaneswar , Odisha , India
| | | | - Sabita Nayak
- a Department of Chemistry , Ravenshaw University , Cuttack , Odisha , India
| |
Collapse
|
56
|
Hasaninejad A, Firoozi S. Catalyst-free, one-pot, three-component synthesis of 5-amino-1,3-aryl-1 $$H$$ -pyrazole-4-carbonitriles in green media. Mol Divers 2013; 17:459-69. [DOI: 10.1007/s11030-013-9445-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 04/09/2013] [Indexed: 11/30/2022]
|
57
|
Verma D, Kumar R, Namboothiri INN. Synthesis of Withasomnines and Their Non-natural Analogues from Aldehydes and 4-Nitro-1-butanol in Three Steps. J Org Chem 2013; 78:3482-6. [DOI: 10.1021/jo400207u] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Deepti Verma
- Department of Chemistry, Indian Institute of Technology, Bombay, Mumbai 400 076, India
| | - Rahul Kumar
- Department of Chemistry, Indian Institute of Technology, Bombay, Mumbai 400 076, India
| | | |
Collapse
|
58
|
Hao L, Hong JJ, Zhu J, Zhan ZP. One-Pot Synthesis of Pyrazoles through a Four-Step Cascade Sequence. Chemistry 2013; 19:5715-20. [DOI: 10.1002/chem.201204322] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/18/2013] [Indexed: 11/09/2022]
|
59
|
|
60
|
Xu SX, Hao L, Wang T, Ding ZC, Zhan ZP. Chemoselective synthesis of substituted pyrazoles through AgOTf-catalyzed cascade propargylic substitution-cyclization-aromatization. Org Biomol Chem 2013. [PMID: 23188378 DOI: 10.1039/c2ob27016a] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A cascade AgOTf-catalyzed chemoselective approach to 3,5/1,3-disubstitued pyrazoles from propargylic alcohols and para-tolylsulfonohydrazide has been developed. Good chemoselectivity is observed depending on the different substituents in the alkyne moiety of the propargylic alcohols, generating two different kinds of products through different aromatization mechanisms. The pyrazolo[5,1-a]isoquinoline skeleton can also be effectively constructed by this method through a cascade bicyclization process.
Collapse
Affiliation(s)
- Su-Xia Xu
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, P. R. China
| | | | | | | | | |
Collapse
|
61
|
Yu X, Zhang J. A Base-Promoted Tandem Cycloaddition/Air Oxidation Reaction of Electron-Deficient Conjugated Enynes and Hydrazines: Synthesis of Highly Substituted Pyrazoles. Chemistry 2012; 18:12945-9. [DOI: 10.1002/chem.201202583] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Indexed: 11/09/2022]
|
62
|
Kumar R, Verma D, Mobin SM, Namboothiri INN. One-Pot, Two-Step Conversion of Aldehydes to Phosphonyl- and Sulfonylpyrazoles Using Bestmann–Ohira Reagent. Org Lett 2012; 14:4070-3. [DOI: 10.1021/ol301695e] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Rahul Kumar
- Department of Chemistry and National Single-Crystal X-ray Diffraction Facility, Indian Institute of Technology, Bombay, Mumbai 400 076, India
| | - Deepti Verma
- Department of Chemistry and National Single-Crystal X-ray Diffraction Facility, Indian Institute of Technology, Bombay, Mumbai 400 076, India
| | - Shaikh M. Mobin
- Department of Chemistry and National Single-Crystal X-ray Diffraction Facility, Indian Institute of Technology, Bombay, Mumbai 400 076, India
| | - Irishi N. N. Namboothiri
- Department of Chemistry and National Single-Crystal X-ray Diffraction Facility, Indian Institute of Technology, Bombay, Mumbai 400 076, India
| |
Collapse
|
63
|
Borkin DA, Puscau M, Carlson A, Solan A, Wheeler KA, Török B, Dembinski R. Synthesis of diversely 1,3,5-trisubstituted pyrazoles via 5-exo-dig cyclization. Org Biomol Chem 2012; 10:4505-8. [PMID: 22575899 DOI: 10.1039/c2ob25580d] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
5-Exo-dig cyclocondensation of alk-3-yn-1-ones with hydrazines, in the presence of montmorillonite K-10, provides an effective method with a high atom economy for the synthesis of diversely 1,3,5-trisubstituted pyrazoles. The microwave-accelerated reaction proceeds in the absence of solvent and leads to 5-benzyl substituted pyrazoles with good yields (72-91%). The regiochemistry of the process was confirmed by the X-ray crystallographic structure determination of 1-(2-fluorophenyl)-5-(4-methylbenzyl)-3-phenyl-1H-pyrazole.
Collapse
Affiliation(s)
- Dmitry A Borkin
- Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
| | | | | | | | | | | | | |
Collapse
|
64
|
Liu P, Pan YM, Xu YL, Wang HS. PTSA-catalyzed Mannich-type–cyclization–oxidation tandem reactions: one-pot synthesis of 1,3,5-substituted pyrazoles from aldehydes, hydrazines and alkynes. Org Biomol Chem 2012; 10:4696-8. [PMID: 22592555 DOI: 10.1039/c2ob25487e] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Pei Liu
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), School of Chemistry and Chemical Engineering of Guangxi Normal University, Guilin 541004, People's Republic of China
| | | | | | | |
Collapse
|
65
|
|
66
|
|
67
|
Jin W, Yu H, Yu Z. Regioselective synthesis of multisubstituted pyrazoles via cyclocondensation of β-thioalkyl-α,β-unsaturated ketones with hydrazines. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2011.08.168] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
68
|
Kumar R, Namboothiri INN. Regioselective Synthesis of Sulfonylpyrazoles via Base Mediated Reaction of Diazosulfones with Nitroalkenes and a Facile Entry into Withasomnine. Org Lett 2011; 13:4016-9. [DOI: 10.1021/ol201534f] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Rahul Kumar
- Department of Chemistry, Indian Institute of Technology, Bombay, Mumbai 400 076, India
| | | |
Collapse
|