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Abstract
In the present paper, a simple, highly efficient, and environmentally friendly protocol was proposed for the Knoevenagel condensation reaction of aromatic aldehydes using Meldrum’s acid (2,2-dimethyl-4,6-dioxo-1,3-dioxane) with bentonite as an available non-toxic mineral catalyst exposed to aqueous media under green conditions. Together with the substitution protocol of electron-donating or -withdrawing groups, all reactions were finalized from 5 to 120 min in water at 90°C. With regard to such reactions, the purification of columns on products was not a requirement. Considering the environmental aspect, use of water as a green solvent, utilization of a reusable catalyst, simple work-up process and steps, as well as rapid reaction times were taken into account as some characteristics of these chemical reactions.
Keywords: Arylidene Meldrum's acid, Bentonite (Al2O3.4SiO.H2), Knoevenagel condensation, aqueous media, natural catalyst, electron-donating.
[http://dx.doi.org/10.1081/SCC-120004844]
[http://dx.doi.org/10.1016/S0040-4039(01)00978-9]
[http://dx.doi.org/10.1039/b911951e] [PMID: 19907784]
(b)Atlan, V.; Buron, C.; Karm, L.E. Synlett, 2000, 4, 489-490.
[http://dx.doi.org/10.1016/j.micromeso.2017.03.031]
[http://dx.doi.org/10.1016/j.jcat.2019.11.011]
[http://dx.doi.org/10.1016/j.micromeso.2017.03.011]
[http://dx.doi.org/10.1007/s11164-019-03796-2]
[http://dx.doi.org/10.1016/j.molstruc.2018.10.053]
[http://dx.doi.org/10.1016/j.apcatb.2018.08.021]
[http://dx.doi.org/10.1039/C8RA03833C]
[http://dx.doi.org/10.1016/j.tetlet.2016.04.097]
[http://dx.doi.org/10.1088/1742-6596/1299/1/012119]
[http://dx.doi.org/10.1021/acs.jpcb.7b03191] [PMID: 28471675]
[http://dx.doi.org/10.1016/j.catcom.2011.05.033]
[http://dx.doi.org/10.2174/138620712801619122] [PMID: 22272691]
[http://dx.doi.org/10.2174/1570178616666181203145211]
[http://dx.doi.org/10.1016/j.ejmech.2011.04.005] [PMID: 21521629]
[http://dx.doi.org/10.1002/jhet.5570380318]
[http://dx.doi.org/10.1016/j.ejmech.2011.02.033] [PMID: 21429633]
[http://dx.doi.org/10.1016/S0960-894X(99)00238-3] [PMID: 10386920]
[http://dx.doi.org/10.1007/s13738-014-0499-2]
[http://dx.doi.org/10.1007/s40995-017-0376-9]
[http://dx.doi.org/10.1016/j.apcatb.2017.11.067]
[http://dx.doi.org/10.1016/j.tetlet.2017.05.006]
[http://dx.doi.org/10.1016/j.bioorg.2020.103729] [PMID: 32179284]
[http://dx.doi.org/10.1080/07391102.2019.1578264] [PMID: 30784365]
[http://dx.doi.org/10.5958/0974-4150.2019.00032.4]
[http://dx.doi.org/10.1016/j.ejmech.2006.06.004] [PMID: 16904795]
[http://dx.doi.org/10.2217/pgs.09.125] [PMID: 19842940]
[http://dx.doi.org/10.1016/S0014-827X(02)01264-8] [PMID: 12385519]
[http://dx.doi.org/10.1016/j.bmc.2006.02.042] [PMID: 16540334]
[http://dx.doi.org/10.1016/j.cbi.2016.04.020] [PMID: 27085377]
[http://dx.doi.org/10.1016/j.ultsonch.2017.06.022] [PMID: 28946485]
[http://dx.doi.org/10.1016/j.bmc.2010.06.033] [PMID: 20621497]
[http://dx.doi.org/10.1016/S0040-4020(03)00554-4]
[http://dx.doi.org/10.1021/ja01190a060] [PMID: 18891879]
(b)Corey, E.J. J. Am. Chem. Soc., 1952, 74, 5897-5905.
[http://dx.doi.org/10.1021/ja01143a021]
(c)Kraus, G.A.; Krolski, M.E. J. Org. Chem., 1986, 51, 3347-3350.
[http://dx.doi.org/10.1021/jo00367a017]
(d)Scuster, P.; Polansky, O.E.; Wessely, F. Monatsh. Chem., 1964, 95, 53-58.
[http://dx.doi.org/10.1007/BF00909251]
(e)Isobe, K.; Hoshi, T.; Suzuki, T.; Hagiwara, H. Mol. Divers., 2005, 9(4), 317-320.
[http://dx.doi.org/10.1007/s11030-005-8107-0] [PMID: 16311808]
(f)Fildes, D.; Caignaert, V.; Villemin, D.; Jaffres, P-A. Green Chem., 2001, 3, 52-56.
[http://dx.doi.org/10.1039/b009199p]
(g)Dumas, A.M.; Seed, A.; Zorzitto, A.K.; Fillion, E.A. Tetrahedron Lett., 2007, 48, 7072-7074.
[http://dx.doi.org/10.1016/j.tetlet.2007.08.012]
[http://dx.doi.org/10.1080/00397910600775218]
[http://dx.doi.org/10.1080/00397910008087374]
[http://dx.doi.org/10.1021/jo01067a032]
[http://dx.doi.org/10.1055/s-1994-25453]
[http://dx.doi.org/10.1080/00397910500278362]
[http://dx.doi.org/10.1007/s10593-013-1333-y]
[http://dx.doi.org/10.1039/b501531f] [PMID: 15968377]
[http://dx.doi.org/10.1016/j.tetlet.2011.05.032]
[http://dx.doi.org/10.1016/j.molstruc.2015.03.002]
[http://dx.doi.org/10.1016/j.tetlet.2007.08.012]
[http://dx.doi.org/10.2174/157017806779117076]
[http://dx.doi.org/10.1016/j.tetlet.2011.03.123]
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