title: Successful application of an ionic liquid carrying the fluoride counter-ion in biomacromolecular chemistry: microwave-assisted acylation of cellulose in the presence of 1-allyl-3-methylimidazolium fluoride/DMSO mixtures.
abstract: The use of ionic liquids with fluoride anion (IL-F) is challenging because of side reactions. Neat 1-allyl-3-methylimidazolium fluoride (AlMeImF) is used as a solvent in microwave-assisted acylation of cellulose. The results are disappointing due to side reactions in the IL proper, and F(-) -mediated hydrolysis of the produced ester. A dramatic improvement is observed, when AlMeImF/DMSO mixture is employed. The results are comparable to those obtained when pure 1-allyl-3-methylimidazolium chloride is employed. FTIR spectroscopy shows that dissolving a carboxylic acid anhydride in IL-F leads to the formation of acyl fluoride. Thus ILs are far from being "spectator" solvents. The new approach (use of IL-F/DMSO) is attractive because of its efficiency, low cost, and applicability to the derivatization of any polymer.
authors.affiliation: Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Romeu
authors.initials: R
authors.lastname: Casarano
authors.forename: Omar A
authors.initials: OA
authors.lastname: El Seoud
mesh_terms: D000215:Acylation; D000498:Allyl Compounds / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry; D006868:Hydrolysis; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008872:Microwaves; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: C544334:1-allyl-3-methylimidazolium; D000498:Allyl Compounds; D007093:Imidazoles; D052578:Ionic Liquids; D012997:Solvents; D002482:Cellulose; D005459:Fluorides; D004121:Dimethyl Sulfoxide