Generic placeholder image

Current Organocatalysis

Author(s): Abid H. Banday* and Victor J. Hruby

DOI: 10.2174/2213337207999200831105105

DownloadDownload PDF Flyer Cite As
Ionic Liquid Catalyzed Efficient Regioselective Synthesis of 1,4-Disubstituted 1,2,3-Triazoles Under Metal and Solvent Free Conditions

Page: [223 - 227] Pages: 5

  • * (Excluding Mailing and Handling)

Abstract

Background: Catalyzed organic reactions avoiding the use of metal salts, metal complexes and organometallic compounds have tremendous applications especially within sensitive biological systems. The current work is an effort towards metal and solvent-free organo-catalyzed reactions.

Objective: Unprecedented, one-pot regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles through azide-aldehyde (3+2) organo-click cycloaddition under metal and solvent-free conditions is described.

Methods: The method presents a convenient approach towards the synthesis of functionally versatile 1,4-disubstituted 1,2,3-triazoles from easily accessible substrates using recyclable 1,8-diazabicyclo[ 5.4.0]undec-7-ene (DBU)-based ionic liquids as catalysts.

Results: 1,4-disubstituted 1,2,3-triazoles were obtained in moderate to excellent yield using azidealdehyde (3+2) organo-click cycloaddition under metal and solvent-free conditions.

Conclusion: The procedure reported herein for the synthesis of 1,4-disubstituted 1,2,3-triazoles is straightforward, greener, devoid of tedious workups and chromatographic separation.

Keywords: Solvent-free reactions, metal free reactions, enolizable aldehydes, 1, 2, 3-Triazoles, regioselective reactions, non- CuAAC, ionic liquids.

Graphical Abstract

[1]
aDheer, D.; Singh, V.; Shankar, R. Medicinal attributes of 1,2,3- triazoles: Current developments. Bioorg. Chem., 2017, 71, 30-54.
bJewett, J.C.; Bertozzi, C.R. Cu-free click cycloaddition reactions in chemical biology. Chem. Soc. Rev., 2010, 39(4), 1272-1279.
[http://dx.doi.org/10.1016/j.bioorg.2017.01.010] [PMID: 28126288] [http://dx.doi.org/10.1039/b901970g] [PMID: 20349533]
[2]
Agalave, S.G.; Maujan, S.R.; Pore, V.S. Click chemistry: 1,2,3-triazoles as pharmacophores. Chem. Asian J., 2011, 6(10), 2696-2718.
[http://dx.doi.org/10.1002/asia.201100432] [PMID: 21954075]
[3]
Lewis, J.E.M.; McAdam, C.J.; Gardiner, M.G.; Crowley, J.D. A facile “click” approach to functionalised metallosupramolecular architectures. Chem. Commun. (Camb.), 2013, 49(33), 3398-3400.
[http://dx.doi.org/10.1039/c3cc41209a] [PMID: 23515345]
[4]
Comprehensive Heterocyclic Chemistry Wamhoff, H.; Katritzky, A.R.; Rees, C.W.; Scriven, E.F.V., Eds.; Elsevier Science: Oxford,; , 1996.
[5]
Hein, J.E.; Fokin, V.V. Copper-catalyzed azide-alkyne cycloaddition (CuAAC) and beyond: new reactivity of copper(I) acetylides. Chem. Soc. Rev., 2010, 39(4), 1302-1315.
[http://dx.doi.org/10.1039/b904091a] [PMID: 20309487]
[6]
Aromi, G.; Barrios, L.A.; Rubeau, O.; Gamez, P. Triazoles and tetrazoles: Prime ligands to generate remarkable coordination materials. Coord. Chem. Rev., 2011, 255, 485-546.
[http://dx.doi.org/10.1016/j.ccr.2010.10.038]
[7]
Sletten, E.M.; Bertozzi, C.R. From mechanism to mouse: a tale of two bioorthogonal reactions. Acc. Chem. Res., 2011, 44(9), 666-676.
[http://dx.doi.org/10.1021/ar200148z] [PMID: 21838330]
[8]
aHong, L.; Lin, W.; Zhang, F.; Liu, R.; Zhou, X. Ln[N(SiMe3)2]3-catalyzed cycloaddition of terminal alkynes to azides leading to 1,5-disubstituted 1,2,3-triazoles: new mechanistic features. Chem. Commun. (Camb.), 2013, 49(49), 5589-5591.
bRostovtsev, V.V.; Green, L.G.; Fokin, V.V.; Sharpless, K.B. A stepwise huisgen cycloaddition process: copper(I)-catalyzed regioselective “ligation” of azides and terminal alkynes. Angew. Chem. Int. Ed. Engl., 2002, 41(14), 2596-2599.
[http://dx.doi.org/10.1039/c3cc42534g] [PMID: 23676902] [http://dx.doi.org/10.1002/1521-3773(20020715)41:14<2596::AID-ANIE2596>3.0.CO;2-4] [PMID: 12203546]
[9]
Liu, P.N.; Li, J.; Su, H.F.; Ju, K.D.; Zhang, L.; Shi, C.; Sung, H.H.Y.; Williams, I.D.; Fokin, V.V.; Lin, Z.; Jia, G. Synthesis of 1-Cyanoalkynes and Their Ruthenium(II)-Catalyzed Cycloaddition with Organic Azides to Afford 4-Cyano-1,2,3-triazoles. Organometallics, 2012, 31, 4904-5103.
[http://dx.doi.org/10.1021/om300513w]
[10]
Baskin, J.M.; Bertozzi, C.R. Bioorthogonal Click Chemistry: Covalent Labeling in Living Systems. QSAR Comb. Sci., 2007, 26, 1211-1219.
[http://dx.doi.org/10.1002/qsar.200740086]
[11]
Cheng, G.; Zeng, X.; Shen, J.; Wang, X.; Cui, X. A Metal-Free Multicomponent Cascade Reaction for the Regiospecific Synthesis of 1,5-Disubstituted 1,2,3-Triazoles. Angew. Chem. Int. Ed., 2013, 52, 13265-13268.
[http://dx.doi.org/10.1002/anie.201307499]
[12]
Ramachary, D.B.; Shashank, A.B.; Karthik, S. An organocatalytic azide-aldehyde [3+2] cycloaddition: high-yielding regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles. Angew. Chem. Int. Ed. Engl., 2014, 53(39), 10420-10424.
[http://dx.doi.org/10.1002/anie.201406721] [PMID: 25079606]
[13]
Ying, A.; Li, Z.; Yang, J.; Liu, S.; Xu, S.; Yan, H.; Wu, C. DABCO-based ionic liquids: recyclable catalysts for aza-Michael addition of α,β-unsaturated amides under solvent-free conditions. J. Org. Chem., 2014, 79(14), 6510-6516.
[http://dx.doi.org/10.1021/jo500937a] [PMID: 24950008]
[14]
aBanday, A.H.; Hruby, V.J. Cu(I)–Pd(II)-Catalyzed Cycloaddition–Fusion of 1-Iodoalkynes and Azides: One-Pot Synthesis of Fused Tricyclic Heterosystems. Synlett, 2014, 25(17), 246-249.
bBanday, A.H.; Hruby, V.J. Regioselective N/C-heterocyclization of allenylindium bromide across aryl azides: One-pot synthesis of 5-methyl-1,2,3-triazoles. Synlett, 2014, 25(13), 1859-1862.
cBanday, A.H.; Arora, B.S.; Alam, M.S.; Kumar, H.M.S. A Novel Domino-Click Approach to Unsymmetrical Bis-1H-1,2,3-triazoles. Helv. Chim. Acta, 2007, 90, 2368-2374.
dShafi, S.; Banday, A.H.; Ismail, T.; Kumar, H.M.S. Domino Addition/N-C Heterocyclization of Azides with Allenyl Magnesium Bromide: Rapid Synthesis of 5-Butynyl-1,2,3-triazoles. Synlett, 2007, 7, 1109-1111.
[http://dx.doi.org/10.1055/s-0034-1378582] [http://dx.doi.org/10.1055/s-0034-1378327] [http://dx.doi.org/10.1002/hlca.200790242]
[15]
Singh, H.; Khurana, J.M. Synthesis of biologically as well as industrially important 1,4,5-trisubstituted-1,2,3-triazoles using a highly efficient, green and recyclable DBU–H2O catalytic system. RSC Advances, 2013, 3, 22360-22366.
[http://dx.doi.org/10.1039/c3ra44440f]