Simple and efficient method for the synthesis of highly substituted imidazoles using zeolite-supported reagents

Current advances in the synthesis and biological potencies of tri- and tetra-substituted 1H-imidazoles

“…Inorganic or organic matrixsupported catalysts and nano catalysts (bioglycerol-based carbon catalysts) [102], nano-SnCl 4 ·SiO 2 [103], BF 3 -SiO 2 [104], HClO 4 -SiO 2 [105], NaHSO 4 /silica gel [106], silica sulfuric acid [107], NiCl 2 ·6H 2 O/Al 2 O 3 [108], HBF 4 -SiO 2 [109], Amberlyst A-15 [110], polymer-supported ZnCl 2 [111], SBA-15/TFE (SBA-15/2,2,2-trifluoroethanol) [112], SBA-Pr-SO 3 H [113], silica-supported tin oxide nanoparticles (SiO 2 :SnO 2 ) [114], ferric(III) nitrate supported on kieselguhr (Fe(NO 3 )3-Kie) [115], zeolite-supported reagents [116], nanocrystalline MgO [117], nano-crystalline sulfated zirconia [118], magnetic Fe 3 O 4 nanoparticles [119], heteropolyacids [120] organocatalysts, such as L-proline [121], DABCO [122], enzymes (e.g., Lipase [123], papain [124]), trichloromelamine [125]), p-toluene sulfonic acid [126], ammonium chloride (NH 4 Cl) [127], NaH 2 PO 4 [128], mercaptopropylsilica [129], sodium bisulfate [130], ceric ammonium nitrate [131], morpholinium hydrogen sulphate [132], diethyl ammonium hydrogen phosphate [133], sulfated tin oxide [134], urea/hydrogen peroxide [135], silicabound propylpiperazine N -sulfamic [136], tetrabutylammonium bromide (TBAB) [137], sodium bisulfate [128], potassium aluminum sulfate (alum) [138], l-cysteine …”

Zinc (II) [tetra(4-methylphenyl)] Porphyrin: a Novel and Reusable Catalyst for Efficient Synthesis of 2,4,5-trisubstituted Imidazoles Under Ultrasound Irradiation

“…14 Multisubsti- 36 and ionic liquids. [37][38][39] Despite their potential utility, most of these methods have a number of drawbacks including poor yields, high temperature, use of toxic catalyst, strongly acidic conditions and the requirement for harsh reaction conditions.…”

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.…”