A novel neutral ionic liquid-catalyzed solvent-free synthesis of 2,4,5-trisubstituted imidazoles under microwave irradiation

The Beneficial Sinergy of MW Irradiation and Ionic Liquids in Catalysis of Organic Reactions

“…Imidazolium salts with different alkyl chains were used as catalysts in a MW-irradiated MCR leading to tri-substituted imidazoles [144]. The most efficient catalyst was 1-heptyl-3-methylimidazolium tetrafluoroborate that was also easy to recover and recycle.…”

“…Compared to other catalysts (Brønsted or Lewis acids), Bu4NBr was one of the most efficient, giving Scheme 58. Tri-substituted imidazoles via MW-heated, IL-catalyzed MCR [144].…”

BF3/nano-sawdust as a green, biodegradable and inexpensive catalyst for one-pot synthesis of tri-substituted imidazoles under solvent free conditions

“…The majority of synthetic routes rely on one-pot condensation of diketones or -hydroxyketones with an aldehyde and ammonium acetate in the presence of catalysts such as silica gel or zeolite [9], alumina [10], molecular iodine [11], neutral ionic liquid [12], L-Proline [13], nano-crystalline Sulfated Zirconia (SZ) [14], DABCO [15], AcOH [16], zeolitesupported reagents [17], silica sulfuric acid [18], PEG-400 [19], InF 3 [20], nanocrystalline magnesium ox- [24], and bioglycerol-based carbon catalyst [25]. Some of these catalysts are ideal choices for the synthesis of 2,4,5-tri-substituted imidazoles and are often used for this purpose.…”

A novel and an efficient catalyst for one-pot synthesis of 2,4,5-trisubstituted imidazoles by using microwave irradiation under solvent-free conditions

“…26 A number of methods have been developed for the synthesis of 2,4,5-trisubstituted imidazoles. 2,4,5-Trisubstituted imidazoles are generally synthesized by three-component cyclocondensation of a 1,2-diketone, α-hydroxyketone or α-ketomonoxime with an aldehyde and ammonium acetate, which comprise the use of microwaves, [27][28][29][30] ionic liquids, [31][32][33][34][35] and Lproline. 53 Moreover, they have also been prepared by the addition of a substituted amino alcohol to a thioamide and subsequent oxidation with PDC 54 or by the reaction of aryl nitriles and α,α-dilithioarylnitromethanes 55 or by multistep syntheses 56,57 .…”