Nano-Sized and -Crystalline Sulfated Zirconia Solid Acid Catalysts for Organic Synthesis

Article Preview

Abstract:

Sulfated Zirconia (SZ) has opened up a very interesting area for application predominantly as catalyst for various acid catalyzed organic syntheses and transformation reactions. Catalytic properties of SZ vary with methods of preparation. Lot of efforts is made to modify SZ to increase reactivity and stability of the catalyst. This review focuses on the individual synthesis routes to prepare nano-sized and –crystalline SZ, short discussion on its characterization and exhaustive survey on its utility in organic chemistry for the development of new synthetic methodologies, which provide simple direction having enormous practical significance. As can be realized, the nano-sized and –crystalline SZ as solid acid catalyst exhibits exceptionally better catalytic activity and selectivity for the synthesis of trisubstituted and tetrasubstituted imidazoles, acetyl salicylic acid, dypnone, esterification of acetic acid, caprylic acid and so on.

You might also be interested in these eBooks

Info:

Periodical:

Pages:

69-83

Citation:

Online since:

May 2013

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2013 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] B. M. Reddy, M. K. Patil, Organic Syntheses and Transformations Catalyzed by Sulfated Zirconia, Chem. Rev. 109 (2009) 2185-2208.

DOI: 10.1021/cr900008m

Google Scholar

[2] A. Feller, J. A. Lercher, Chemistry and Technology of Isobutane/Alkene Alkylation Catalyzed by Liquid and Solid Acids, Adv. Catal. 48 (2004) 229-295.

DOI: 10.1016/s0360-0564(04)48003-1

Google Scholar

[3] B. M. Reddy, M. K. Patil, Promoted zirconia solid acid catalysts for organic synthesis, Curr. Org. Chem. 12 (2008) 118-140.

DOI: 10.2174/138527208783330019

Google Scholar

[4] G. D. Yadav, J. J.Nair, Sulfated zirconia and its modified versions as promising catalysts for industrial processes, Microporous Mesoporous Mater. 33 (1999) 1-48.

DOI: 10.1016/s1387-1811(99)00147-x

Google Scholar

[5] M. K. Patil, A. N. Prasad, B. M. Reddy, Zirconia-based solid acids: Green and heterogeneous catalysts for organic synthesis, Curr. Org. Chem.15 (2011) 3961-3985.

DOI: 10.2174/138527211798072430

Google Scholar

[6] X. M. Song, A. Sayari, Sulfated Zirconia-Based Strong Solid-Acid Catalysts: Recent Progress, Catal. Rev. 38 (1996) 329-412.

DOI: 10.1080/01614949608006462

Google Scholar

[7] A. Corma, Attempts to fill the gap between enzymatic, homogeneous, and heterogeneous catalysis, Catal. Rev. -Sci. Eng. 46 (2004) 369-417.

DOI: 10.1081/cr-200036732

Google Scholar

[8] G. A. Olah, G. K. S. Prakash, J. Sommer, Superacids; John Wiley and Sons: New York, 1985.

Google Scholar

[9] G. A. Olah, G. K. S. Prakash, J. Sommer, Superacids, Science 206 (1979) 13-20.

Google Scholar

[10] K. Arata, Solid Superacids, Adv. Catal. 37 (1990) 165-211.

Google Scholar

[11] B. H. Davis, R. A. Keogh, R. Srinivasan, Sulfated zirconia as a hydrocarbon conversion catalyst, Catal. Today 20 (1994) 219-256.

DOI: 10.1016/0920-5861(94)80004-9

Google Scholar

[12] T. Yamaguchi, Recent progress in solid superacid, Appl. Catal. 61 (1990) 1-25.

Google Scholar

[13] R. J. Gillespie, Fluorosulfuric acid and related superacid media, Acc. Chem. Res. 1 (1968) 202-209.

DOI: 10.1021/ar50007a002

Google Scholar

[14] R. J. Gillespie, T. E. Peel, Superacid systems, Adv. Phys. Org. Chem. 9 (1971) 1-24.

Google Scholar

[15] H. Matsuhashi, H. Nakamura, T. Ishihara, S. Iwamoto, Y. Kamiya, J. Kobayashi, Y. Kubota, T. Yamada, T. Matsuda, K. Matsushita, K. Nakai, H. Nishiguchi, M. Ogura, N., N. Okazaki, S. Sato, K. Shimizu, T. Shishido, S. Yamazoe, T. Takeguchi, K. Tomishige, H. Yamashita, M. Niwa, N. Katada, Characterization of sulfated zirconia prepared using reference catalysts and application to several model reactions, Appl. Catal. A: Gen. 360 (2009) 89-97.

DOI: 10.1016/j.apcata.2009.03.012

Google Scholar

[16] C.-Y. Hsu, C. R. Heimbuch, C. T. Armes, B. C. Gates, A highly active solid superacid catalyst for n-butane isomerization: A sulfated oxide containing iron, manganese and zirconium, J. Chem. Soc., Chem. Commun. (1992) 1645-1646.

DOI: 10.1039/c39920001645

Google Scholar

[17] E. Rubio, V. Rodriguez-Lugo, R. Rodriguez, V. M. Castano, Nano Zirconia and Sulfated Zirconia from Ammonia Zirconium Carbonate, Rev. Adv. Mater. Sci. 22 (2009) 67-73.

Google Scholar

[18] A. Teimouri, A. N. Chermahini, An efficient and one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed via solid acid nano-catalyst, J. Mol. Catal. A: Chem. 346 (2011) 39-45.

DOI: 10.1016/j.molcata.2011.06.007

Google Scholar

[19] G. Boskovic, A. R. Zarubica, P. Putanov, Precursor affected properties of nanostructured sulfated zirconia: Morphological, textural and structural correlations, J. Optoelectro. Adv. Mater. 9 (2007) 2251-2257.

Google Scholar

[20] B. Tyagi, M. K. Mishra, R. V. Jasra, Solvent free synthesis of acetyl salicylic acid over nano-crystalline sulfated zirconia solid acid catalyst, J. Mol. Catal. A: Chem. 317 (2010) 41-45.

DOI: 10.1016/j.molcata.2009.10.019

Google Scholar

[21] B. R. Vahid, N. Saghatoleslami, H. Nayebzadeh, A. Maskooki Preparation of nano-size Al-promoted sulfated zirconia and the impact of calcination temperature on its catalytic activity, Chem. Biochem. Eng. Q. 26 (2012) 71-77.

Google Scholar

[22] R. Lloyd, T. W. Hansen, W. Ranke, F. C. Jentoft, R. Schlögl, Adsorption-desorption equilibrium investigations of n-butane on nanocrystalline sulfated zirconia thin films, Appl. Catal. A: Gen. 391 (2011) 215-224.

DOI: 10.1016/j.apcata.2010.06.028

Google Scholar

[23] S. Yu, P. Jiang, Y. Dong, P. Zhang, Y. Zhang, W. Zhang, Hydrothermal Synthesis of Nanosized Sulfated Zirconia as an Efficient and Reusable Catalyst for Esterification of Acetic Acid with n-Butanol, Bull. Korean Chem. Soc. 33 (2012) 524-528.

DOI: 10.5012/bkcs.2012.33.2.524

Google Scholar

[24] K. Saravanan, B. Tyagi, H. C. Bajaj, Synthesis of dypnone by solvent free self condensation of acetophenone over nano-crystalline sulfated zirconia catalyst, J. Sol-Gel Sci. Technol. 61 (2012) 275-280.

DOI: 10.1007/s10971-011-2624-3

Google Scholar

[25] B. Tyagi, M. K. Mishra, R. V. Jasra, Synthesis and characterization of nano-crystalline sulfated zirconia by sol-gel method, J. Mol. Catal. A: Chem. 223 (2004) 61-65.

DOI: 10.1016/j.molcata.2003.09.040

Google Scholar

[26] Y. Sun, S. Ma, Y. Du, L. Yuan, S. Wang, J. Yang, F. Deng, F.-S. Xiao, Solvent-Free Preparation of Nanosized Sulfated Zirconia with Brønsted Acidic Sites from a Simple Calcination, J. Phys. Chem. B 109 (2005) 2567-2572.

DOI: 10.1021/jp046335a

Google Scholar

[27] R. Lloyd, T. W. Hansen, W. Ranke, F. C. Jentoft, R. Schlögl, Adsorption-desorption equilibrium investigations of n-butane on nanocrystalline sulfated zirconia thin films, Appl. Catal. A: Gen. 391 (2011) 215-224.

DOI: 10.1016/j.apcata.2010.06.028

Google Scholar

[28] X. Li, K. Nagaoka, L. J. Simon, R. Olindo, J. A. Lercher, Mechanism of butane skeletal isomerization on sulfated zirconia, J. Catal. 232 (2005) 456-466.

DOI: 10.1016/j.jcat.2005.03.025

Google Scholar

[29] X. Li, K. Nagaoka, J. A. Lercher, Labile sulfates as key components in active sulfated zirconia for n-butane isomerization at low temperatures, J. Catal. 227 (2004) 130-137.

DOI: 10.1016/j.jcat.2004.07.003

Google Scholar

[30] T. Funamoto, T. Nakagawa, K. Segawa, Isomerization of n-butane over sulfated zirconia catalyst under supercritical conditions, Appl. Catal. A: Gen. 286 (2005) 79-84.

DOI: 10.1016/j.apcata.2005.03.005

Google Scholar

[31] A. Corma, J. M. Serra, A. Chica, Discovery of new paraffin isomerization catalysts based on SO4 2-/ZrO2 and WOx/ZrO2 applying combinatorial techniques, Catal. Today 81(2003) 495-506.

DOI: 10.1016/s0920-5861(03)00148-2

Google Scholar

[32] N. Essayem, Y. Ben Taarit, C. Feche, P. Y. Gayraud, G. Sapaly, C. Naccache, Comparative study of n-pentane isomerization over solid acid catalysts, heteropolyacid, sulfated zirconia, and mordenite: Dependence on hydrogen and platinum addition, J. Catal. 219 (2003) 97-106.

DOI: 10.1016/s0021-9517(03)00162-3

Google Scholar

[33] S. Rezgui, R. E. Jentoft, B. C. Gates, n-pentane isomerization and disproportionation catalyzed by promoted and unpromoted sulfated zirconia, Catal. Lett. 51(1998) 229-234.

DOI: 10.1007/bf00813511

Google Scholar

[34] V. Adeeva, H. -Y. Liu, B. -Q. Xu, W. M. H. Sachtler, Alkane isomerization over sulfated zirconia and other solid acids, Top. Catal. 6 (1998) 61-67.

DOI: 10.1002/chin.199848301

Google Scholar

[35] B. M. Reddy, P. M. Sreekanth, P. Lakshmanan, Sulfated zirconia as an efficient catalyst for organic synthesis and transformation reactions, J. Mol.Catal. A: Chem. 237 (2005) 93-100.

DOI: 10.1016/j.molcata.2005.04.039

Google Scholar

[36] M. Gopalakrishnan, P. Sureshkumar, V. Kanagarajan, J. Thanusu, R. Govindaraju, M. R. Ezhilarasi, Microwave-promoted facile and rapid solvent-free synthesis procedure for the efficient synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones using ZrO2/SO4 2- as a reusable heterogeneous catalyst, Lett. Org. Chem .3 (2006) 484-488.

DOI: 10.2174/157017806777828493

Google Scholar

[37] D. Kumar, M. S. Sundaree, B. G. Mishra, Sulfated zirconia-catalyzed one-pot benign synthesis of 3,4-dihydropyrimidin-2(1H)-ones under microwave irradiation ,Chem. Lett. 35 (2006) 1074-1075.

DOI: 10.1246/cl.2006.1074

Google Scholar

[38] B. M. Reddy, B. Thirupathi, M. K. Patil, Highly efficient promoted zirconia solid acid catalysts for synthesis of α-aminonitriles using trimethylsilyl cyanide, J. Mol. Catal. A: Chem. 307 (2009) 154-159.

DOI: 10.1016/j.molcata.2009.03.022

Google Scholar

[39] B. Das, M. Krishnaiah, K. Laxminarayana, K. R. Reddy, A simple and efficient one-pot synthesis of β-acetamido carbonyl compounds using sulfated zirconia as a heterogeneous recyclable catalyst , J. Mol. Catal. A: Chem. 270 (2007) 284-288.

DOI: 10.1016/j.molcata.2007.02.014

Google Scholar

[40] D. Angeles-Beltran, L. Lomas-Romero, V. H. Lara-Corona, E. Gonza-lez-Zamora, G. Negro´n-Silva, Sulfated zirconia-catalyzed synthesis of 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) under solvent less conditions: Competitive multicomponent Biginelli vs. Hantzsch reactions, Molecules 11 (2006) 731-738.

DOI: 10.3390/11100731

Google Scholar

[41] B. M. Reddy, P. M. Sreekanth, An efficient zirconia catalyst for solvent free tetrahydropyranylation of alcohols and phenols, Syn. Commun. 32 (2002) 3561-3564.

DOI: 10.1081/scc-120014966

Google Scholar

[42] C.-H. Lin, M.-Y. Wan, Y.-M. Huang, Methoxymethylation of alcohols catalyzed by sulfated metal oxides, Catal. Lett. 87 (2003) 253-256.

Google Scholar

[43] N. Raju, Sulfated Zirconia: An Efficient Catalyst for the Synthesis of 1, 1-Diacetates from Aldehydes and Ketones, J. Chem. Res. (1996) 68.

Google Scholar

[44] G. E. Negron, L. N. Palaciosa, D. Angelesa, L. Lomasb, R. Gavinoc, R. A mild and efficient method for the chemoselective synthesis of acylals from aromatic aldehydes and their deprotections catalyzed by sulfated zirconia, J. Braz. Chem. Soc. 16 (2005) 490-494.

DOI: 10.1590/s0103-50532005000300025

Google Scholar

[45] D. E. Lopez, J. G. Goodwin Jr., D. A. Bruce, E. Lotero, Transesterification of triacetin with methanol on solid acid and base catalysts, Appl. Catal. A: Gen. 295 (2005) 97-105.

DOI: 10.1016/j.apcata.2005.07.055

Google Scholar

[46] S. Z. M. Shamshuddin, N. Nagaraju, N. Transesterification: Salol synthesis over solid acids, Catal. Commun. 7 (2006) 593-599.

DOI: 10.1016/j.catcom.2006.01.019

Google Scholar

[47] D. E. Lopez, J. G. Goodwin Jr., D. A. Bruce, S. Furuta, Esterification and transesterification using modified-zirconia catalysts, Appl. Catal. A: Gen. 339 (2008) 76-83.

DOI: 10.1016/j.apcata.2008.01.009

Google Scholar

[48] B. Das, R. Ramu, B. Ravikanth, K. R. Reddy, Regioselective ring-opening of aziridines with potassium thiocyanate and thiols using sulfated zirconia as a heterogeneous recyclable catalyst, Tetrahedron Lett. 47 (2006) 779-782.

DOI: 10.1016/j.tetlet.2005.11.105

Google Scholar

[49] B. Das, P. Thirupathi, R. A. Kumar, Sulfated zirconia as an efficient recyclable heterogeneous catalyst for selective aminolysis of epoxides and N-tosyl aziridines under solvent-free condition, Indian J. Heterocycl. Chem. 17 (2008) 339-342.

Google Scholar

[50] B. M. Reddy, M. K. Patil, B. T. Reddy, S.-E. Park, Efficient synthesis of β-amino alcohols by regioselective ring-opening of epoxides with anilines catalyzed by sulfated zirconia under solvent-free conditions, Catal. Commun. 9 (2008) 950-954.

DOI: 10.1016/j.catcom.2007.09.029

Google Scholar

[51] G. Negron-Silva, C. X. Hernandez-Reyes, D. Angeles-Beltran, L. Lomas-Romero, E. Gonzalez-Zamora, Microwave-enhanced sulphated zirconia and SZ/MCM-41 catalyzed regioselective synthesis of β-amino alcohols under solvent-free conditions, Molecules 13 (2008) 977-985.

DOI: 10.3390/molecules13040977

Google Scholar

[52] B. Das, P. Thirupathi, R. A. Kumar, K. R. Reddy, Efficient synthesis of 3-alkyl indoles through regioselective ring opening of epoxides catalyzed by sulfated zirconia, Catal. Commun. 9 (2008) 635-638.

DOI: 10.1016/j.catcom.2007.07.004

Google Scholar

[53] B. M. Reddy, P. M. Sreekanth, P. Lakshmanan, Sulfated zirconia as an efficient catalyst for organic synthesis and transformation reactions, J. Mol.Catal. A: Chem. 237 (2005) 93-100.

DOI: 10.1016/j.molcata.2005.04.039

Google Scholar

[54] B. M. Reddy, P. M. Sreekanth, An efficient synthesis of 1, 5-benzodiazepine derivatives catalyzed by a solid superacid sulfated zirconia, Tetrahedron Lett. 44 (2003) 4447-4449.

DOI: 10.1016/s0040-4039(03)01034-7

Google Scholar

[55] G. D. Yadav, S. Sengupta, Friedel-Crafts alkylation of diphenyl oxide with benzyl chloride over sulphated zirconia, Org. Process Res. Dev. 6 (2002) 256-262.

DOI: 10.1021/op990099y

Google Scholar

[56] G. D. Yadav, G. S. Pathre, Chemoselective catalysis by sulphated zirconia in O-alkylation of guaiacol with cyclohexene, J. Mol. Catal. A: Chem. 243 (2005) 77-84.

DOI: 10.1016/j.molcata.2005.08.024

Google Scholar

[57] G. D. Yadav, P. Ramesh, Selectivity engineering in the O-versus C-alkylation of p-cresol with cyclohexene over sulfated zirconia, Can. J. Chem. Eng. 78 (2000) 917-927.

DOI: 10.1002/cjce.5450780509

Google Scholar

[58] G. D. Yadav, M. S. M. M. Rahuman, Efficacy of solid acids in the synthesis of butylated hydroxy anisoles by alkylation of 4-methoxyphenol with MTBE, Appl. Catal. A: Gen. 253 (2003) 113-123.

DOI: 10.1016/s0926-860x(03)00474-5

Google Scholar

[59] G. D. Yadav, T. S. Thorat, Kinetics of alkylation of p-cresol with isobutylene catalyzed by sulfated zirconia, Ind. Eng. Chem. Res. 35 (1996) 721-731.

DOI: 10.1021/ie940340r

Google Scholar

[60] N. Katada, J.-i. Endo, K.-i. Notsu, N. Yasunobu, N. Naito, M. Niwa, Superacidity and catalytic activity of sulfated zirconia, J. Phys. Chem. B 104 (2000) 10321-10328.

DOI: 10.1021/jp002212o

Google Scholar

[61] H. Nagai, K. Kawahara, S. Matsumura, K. Toshima, Novel stereocontrolled α- and β-glycosidations of mannopyranosyl sulfoxides using environmentally benign heterogeneous solid acids, Tetrahedron Lett. 42 (2001) 4159-4162.

DOI: 10.1016/s0040-4039(01)00674-8

Google Scholar

[62] K. Toshima, K. Kasumi, S. Matsumura, Novel stereocontrolled glycosidations of 2-deoxyglucopyranosyl fluoride using a heterogeneous solid acid, sulfated zirconia (SO4/ZrO2), Synlett (1999) 813-815.

DOI: 10.1055/s-1999-2742

Google Scholar

[63] K. Toshima, K. Kasumi, S. Matsumura, Novel stereocontrolled glycosidations using a solid acid, SO4/ZrO2, for direct syntheses of α- and β-mannopyranosides, Synlett (1998) 643-645.

DOI: 10.1055/s-1998-1741

Google Scholar

[64] L. Grzona, N. Comelli, O. Masini, E. Ponzi, M. Ponzi, Liquid phase isomerization of α-pinene. Study of the reaction on sulfated ZrO2, React. Kinet. Catal. Lett. 69 (2000) 271-276.

DOI: 10.1023/a:1005643731718

Google Scholar

[65] N. A. Comelli, E. N. Ponzi, M. I. Ponzi, α-Pinene isomerization to camphene: Effect of thermal treatment on sulfated zirconia, Chem. Eng. J. 117 (2006) 93-99.

DOI: 10.1016/j.cej.2005.08.006

Google Scholar

[66] F. T. Sejidov, Y. Mansoori, N. J. Goodarzi, Esterification reaction using solid heterogeneous acid catalysts under solvent-less condition, J. Mol. Catal. A: Chem. 240 (2005) 186-190.

DOI: 10.1016/j.molcata.2005.06.048

Google Scholar

[67] S. Ardizzone, C. L. Bianchi, G. Cappelletti, and F. Porta, Liquid-phase catalytic activity of sulfated zirconia from sol-gel precursors: The role of the surface features, J. Catal. 227 (2004) 470-478.

DOI: 10.1016/j.jcat.2004.07.030

Google Scholar

[68] B. M. Reddy, M. K. Patil, K. N. Rao, G. K. Reddy, An easy-to-use heterogeneous promoted zirconia catalyst for Knoevenagel condensation in liquid phase under solvent-free conditions, J. Mol. Catal. A: Chem. 258 (2006) 302-307.

DOI: 10.1016/j.molcata.2006.05.065

Google Scholar

[69] B. M. Reddy, M. K. Patil, B. T. Reddy, An efficient protocol for Aza-michael addition reactions under solvent-free condition employing sulfated zirconia catalyst, Catal. Lett. 126 (2008) 413-418.

DOI: 10.1007/s10562-008-9646-7

Google Scholar

[70] A. Wali, S. M. Pillai, Cyclodehydration of some 1, n-diols catalysed by sulfated zirconia, J. Chem. Res. (1999) 326-327.

DOI: 10.1039/a807189f

Google Scholar

[71] J. C. Rodriguez-Dominguez, G. Kirsch, Sulfated zirconia, a mild alternative to mineral acids in the synthesis of hydroxycoumarins, Tetrahedron Lett. 47 (2006) 3279-3281.

DOI: 10.1016/j.tetlet.2006.03.030

Google Scholar

[72] B. Thirupathi, A. N. Prasad, R. Srinivas, B. M. Reddy, Sulfated zirconia: An efficient catalyst for solvent-free synthesis of silyl ethers under mild conditions, Synth. Commun., 41 (2011) 2064-2072.

DOI: 10.1080/00397911.2010.497591

Google Scholar

[73] J.G. Lambardino, E.H. Wiseman, Preparation and anti-inflammatory activity of some non acidic trisubstituted imidazoles, J. Med. Chem. 17 (1974) 1182-1188.

DOI: 10.1021/jm00257a011

Google Scholar

[74] A. Puratchikody, M. Doble, Antinociceptive and anti-inflammatory activities and QSAR studies on 2-substituted-4, 5-diphenyl-1H-imidazoles, Bioorg. Med. Chem. Lett. 15 (2007) 1083-1090.

DOI: 10.1016/j.bmc.2006.10.025

Google Scholar

[75] K. Saravanan, B. Tyagi, H. C. Bajaj, Esterification of caprylic acid with alcohol over nano-crystalline sulfated zirconia, J. Sol-Gel Sci. Technol. 62 (2012) 13-17.

DOI: 10.1007/s10971-011-2671-9

Google Scholar

[76] B. Tyagi, M. K. Mishra, R. V. Jasra, Solvent free isomerisation of longifolene with nano-crystalline sulphated zirconia, Catal. Commun. 7 (2006) 52-57.

DOI: 10.1016/j.catcom.2005.08.012

Google Scholar

[77] A. Teimouri, A. N. Chermahini, One-pot Green Synthesis of Pyrrole Derivatives Catalyzed by Nano Sulfated Zirconia as a Solid Acid Catalyst, Chin. J. Chem. 30 (2012) 372-376.

DOI: 10.1002/cjoc.201100143

Google Scholar

[78] B. M. Reddy, M. K. Patil, P. Lakshmanan, Sulfated CexZr1−xO2 solid acid catalyst for solvent free synthesis of coumarins, J. Mol. Catal. A: Chem. 256 (2006) 290-294.

DOI: 10.1016/j.molcata.2006.05.001

Google Scholar

[79] B. M. Reddy, B. Thirupathi, M. K. Patil, One-Pot Synthesis of Substituted Coumarins Catalyzed by Silica Gel Supported Sulfuric Acid Under Solvent-Free Conditions, The Open Catal. J. 2 (2009) 33-39.

DOI: 10.2174/1876214x00902010033

Google Scholar

[80] B. Tyagi, M. K. Mishra, R. V. Jasra, Synthesis of 7-substituted 4-methyl coumarins by Pechmann reaction using nano-crystalline sulfated-zirconia, J. Mol. Catal. A: Chem. 276 (2007) 47-56.

DOI: 10.1016/j.molcata.2007.06.003

Google Scholar

[81] A. Teimouri, A. N. Chermahini, A mild and highly efficient Friedländer synthesis of quinolines in the presence of heterogeneous solid acid nano-catalyst, Arab. J. Chem. (2011)

DOI: 10.1016/j.arabjc.2011.05.018

Google Scholar

[82] Y. Sun, L. Zhu, H. Lu, R. Wang, S. Lin, D. Jiang, F.-S. Xiao, Sulfated zirconia supported in mesoporous materials, Appl. Catal. A: Gen. 237 (2002) 21-31.

DOI: 10.1016/s0926-860x(02)00133-3

Google Scholar