Ytterbium triflate as an efficient catalyst for one-pot synthesis of substituted imidazoles through three-component condensation of benzil, aldehydes and ammonium acetate

Environmentally Benign Synthesis of Tetra-Substituted Imidazoles through 4-Components Strategy Mediated by (<I>S</I>)-3-Methyl-1, 1-Diphenylbutane-1, 2-Diamine

“…A lot of synthetic routes are available in the literatures to synthesize imidazoles [11] analogues including annulations of amidines and β-keto esters [12], SBA-Pr-SO 3 H [13], nanocrystalline MgAl 2 O 4 [14], Cellulose/ɤ-Fe 2 O 3 /Ag [15], urea/hydrogen peroxide (UHP) [16], N-acetyl glycine (NAG) [17] [27], 2-cyanopyridine [28], p-TsOH [29], cellulose sulfuric acid [30], ceric (iv) ammonium nitrate (CAN) [31], boric acid [32], PEG-400 [33] [43], eutectic solvents [44], iodine [45], Yb(OTf) 3 [46], ZrCl 4 [47], AcOH [48], disubstituted alkynes [49] are noteworthy. However, almost all of these methods suffer from one or more constraints such as lower yield, harsh reaction conditions, tiresome isolation technique, uses of expensive toxic metal catalysts, limited examples etc.…”

Synthesis of 3H-imidazo[4,5-b] pyridine with evaluation of their anticancer and antimicrobial activity

“…In addition, they can act as antagonists of various biological receptors [26]. Various methods for the synthesis of multi-substituted imidazole derivatives involving different catalysts including AlCl3, FeCl3, Yb(OTf)3, NdCl3, LaCl3 [27], ZrOCl2.8H2O [28], BF3.SiO2, zeolite [29], NaH2PO4 [30], cyclic phosphoric acid [31] and SiO2 [32] etc. The application of microwave irradiation is the use of catalysts or mineral supported reagents, under solvent-free conditions, enables organic reactions to occur expeditiously in ambient pressure, thus providing unique chemical processes with special attributes such as enhanced reaction rates and higher product yields [33,34].…”

Tin oxide nanoparticles (SnO2-NPs): An efficient catalyst for the one-pot synthesis of highly substituted imidazole derivatives

“…They are well known analgesics, anti-inflammatory, antiparasitic, anthelmintic, platelet aggregation inhibitors and antiepileptic agents [8][9][10][11][12][13]. Numerous methods have been reported for the synthesis of highly substituted imidazoles using various catalytic systems such as L-proline [14], ZrCl 4 [15], [16], HClO 4 -SiO 2 [17], BF 3 -SiO 2 [18], heteropolyacids [19], Yb(OTf) 3 [20], molecular iodine [21], silica sulfuric acid [22], cerium ammonium nitrate (CAN) [23], ionic liquids [24], [25] and Schiff base transition metal complex [26]. However, some of these methods suffer from at least one of the following disadvantages such as strongly acidic wastes, high A c c e p t e d M a n u s c r i p t toxicity of the reagent, tedious work-up procedures, unsatisfactory yields, harsh reaction conditions, moisture sensitive catalysts and nonrecyclable reagents.…”