Four-Component, One-Pot Synthesis of Tetra-Substituted Imidazoles Using a Catalytic Amount of MCM-41 or p-TsOH

Magnesium Incorporated White Sandstone as a Green and Efficient Heterogeneous Catalyst for One‐Pot Synthesis of 1,2,3,4‐Tetrasubstituted Pyrroles

“… Condensation reactions of anilines 2a‐j, 1,3‐dicarbonyl compounds, benzaldehyde and nitromethane under the optimized…”

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

“…Several catalyzed reactions were published for the synthesis of 1,2,4,5-tetra-substituted imidazoles using catalysts such as Y(NO 3 [100], bioglycerol-based recyclable carbon catalyst [102], Amberlyst A-15 [110], SBA-15/TFE (SBA-15/2,2,2-trifluoroethanol) [112], SBA-Pr-SO 3 H [113], silicasupported tin oxide nanoparticles [114], magnetic Fe 3 O 4 nanoparticles [119], L-proline [121], p-toluene sulfonic acid (PTSA) [126], solvent-free conditions with sodium dihydrogen phosphate [128], microwave irradiation [141][142][143], FeCl 3 ·6H 2 O [178], fluoroboric acid adsorbed on silica-gel (HBF 4 -SiO 2 ) [179], NHC (N -Heterocyclic Carbene) [180], trifluoroacetic acid [181], a novel organometallic catalyst (PSNP-CA) [182], MCM-41 [183], nano-TiCl 4 ·SiO 2 [184], and clay-supported titanium catalyst [185]. Highly substituted imidazole derivatives can be created using a new four-component and three-step reaction from alkoxyallenes, amines, iodine and nitriles with excellent yields.…”

Catalytic activity of the nanoporous MCM-41 surface for the Paal–Knorr pyrrole cyclocondensation

“…Recently, we have observed the remarkable inherent catalytic activity of MCM-41 mesoporous materials for the preparation of aza heterocyclic compounds, e.g., polyhydroquinolines [35], benzoxazoles [36], and tetra-substituted imidazoles [37].…”