DBU-MIm coupled ionic liquids as reusable catalysts for the Biginelli reaction

Advances in Biginelli reaction: A comprehensive review

“…In 2023, Singh and co-workers established a novel method for the production of dihydropyrimidinones using a reusable catalyst developed by combining two distinct solvent liquids (ILs), 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU) and methylimidazole (MIm). 53 In this reaction, they employed acetylacetone/Àketo ester, urea/thiones, and cinnamaldehyde as model substrates with [DBUH] + [2-MIm] À as the catalyst under solvent- free conditions at 90 C for 45 min., and they got a maximum yield of 82-91% (Scheme 35). For the environmentally friendly and solvent-free generation of DHPMs in the Biginelli reaction, DBU-Im linked ILs were discovered to be effective catalysts.…”

A multi-walled carbon nanotube-supported acidic ionic liquid catalyst for the conversion of biomass-derived saccharides to 5-hydroxymethylfurfural

“…12,13 In recent years, ionic liquids (ILs) have aroused a lot of interest in the catalyst area owing to their unique features like very low vapor pressure, chemical stability, non-volatility, thermal stability, and designability. 14,15 However, IL-type catalysts have challenges in industrial application owing to their poor separation and recoverability. 16 In this regard, immobilization of IL-type catalysts onto solid supports has been recognized to be an effective method to improve their separation and recycling.…”