Novel Dicationic Ionic Liquid as Efficient Catalyst for Morita–Baylis–Hillman Reaction

ABSTRACT In the present study we have reported novel geminal dicationic ionic liquids (DILs) and their catalytic application in the Morita–Baylis–Hillman (MBH) reaction. A novel series of thermally stable 2‐hydroxyethylmorpholinium (HEM)‐based dicationic ionic liquids, namely [HEM][Br] 2 , [HEM][BF 4 ] 2 , and [HEM][PF 6 ] 2 , were synthesized and thoroughly characterized using FT‐IR, NMR, and mass spectrometry, and their thermal stability was further evaluated through thermogravimetric analysis. The catalytic performance of the synthesized DILs was evaluated in the MBH reaction in an aqueous medium. Remarkably, the use of only 0.011 mol% of [HEM][PF 6 ] 2 afforded a 97% yield with a significant enhancement in reaction rate. Furthermore, [HEM][PF 6 ] 2 could be efficiently recovered and reused for up to six consecutive cycles without notable loss of activity. The present protocol offers several advantages, including mild reaction conditions, operational simplicity, use of water:ethanol as a green solvent, higher yields, and comparatively shorter reaction times.