[HyEtPy]Cl–H₂O: an efficient and versatile solvent system for the DABCO-catalyzed Morita–Baylis–Hillman reaction

Abstract

A very efficient and versatile solvent system, [HyEtPy]Cl–H2O, has been developed and used in the DABCO-catalyzed Morita–Baylis–Hillman reaction.

DABCO-catalyzed Knoevenagel condensation of aldehydes with ethyl cyanoacetate using hydroxy ionic liquid as a promoter

“…The product [BuPy]Cl (99 g, 92%) was obtained as white crystalline solid. Mp 87 °C (lit., 38 86 °C); 1 H-NMR (500 MHz, DMSO- d 6 ) δ 0.89 (s, 3H, CH 3 ), 1.28 (s, 2H, CH 2 ), 1.89 (s, 2H, CH 2 ), 4.72 (t, J = 10.0 Hz, 2H, N–CH 2 ), 8.20 (s, 2H, CH ), 8.66 (s, 1H, CH ), 9.35 (s, 2H, CH N + ); 13 C-NMR (125 MHz, DMSO- d 6 ) δ 145.66, 144.77, 128.04, 60.19, 32.60, 18.95, 13.45.…”

“…Preparation and characterization of the ionic salts 1-(2-Hydroxy-ethyl)-pyridinium chloride([HyEtPy]Cl). The ionic salt [HyEtPy]Cl was prepared according to a literature procedure 38 with the following modications: excess 2-chloroethanol (51 mL, 0.76 mol) and pyridine (53 mL, 0.63 mol) were transferred to a 250 mL round bottom ask, which was tted with reux condenser and nitrogen protecting facilities, and the reaction mixture was gently stirred at 70 C for 24 h in the dark; the crude product [HyEtPy]Cl was formed. Then, the crude product was puried by recrystallization with 5 mL acetonitrile and 25 mL ethyl acetate solvent, and the residual solvent was removed in vacuum to give the product The same procedure as that described above for [HyEtPy]Cl was followed except for the use of 1-chlorobutane (99 mL, 0.95 mol) instead of 2-…”

Amino acid ionic liquids as catalysts in a solvent-free Morita–Baylis–Hillman reaction

“…38,40,[42][43][44]47,48 As described in the literature, these two effects added could affect the rate of the MBH reaction in an ionic medium: a supramolecular organization and a favoring of ion pairing.…”

Novel Pyridinium Based Ionic Liquid Promoter for Aqueous Knoevenagel Condensation: Green and Efficient Synthesis of New Derivatives with Their Anticancer Evaluation

“…On the other site, acid-catalyzed by the Knoevenagel reaction would cause the protonation of a carbonyl group that precedes via the attack of a weak nucleophile [26]. Therefore, introducing an ionic liquid with hydroxyl groups might cause an acceleration of the reaction pathway [47,48]. In pursuit of our works on the synthesis of novel ILs and their utilization as catalysts and/or solvents in diverse chemical conversions [43,48,49], we designed and prepared a new ionic liquid ([Py-2OH]OAc) with two hydroxyl groups.…”