Conversion of hexose into 5-hydroxymethylfurfural in imidazolium ionic liquids with and without a catalyst

Conversion of Cellulose to 5-Hydroxymethylfurfural using Inorganic Acidic Catalysts in the Presence of Pressurized Water Steam

“…Acidic catalysts can effectively convert cellulose into HMF by hydrolyzing cellulose to glucose, isomerizing the glucose to fructose, and dehydroyzing the fructose to HMF (Hick et al 2010;Cao et al 2011;Lai and Zhang 2011); this is an important factor in the depolymerization of cellulose. Usually, these processes contain HMF, FF, glucose, fructose, formic acid, levulinic acid, and other byproducts.…”

Imidazolium Ionic Liquids: An Environment-Friendly Medium for Various Applications

“…The Kalkhambkar R G et al approach (2012): The synthesis of 2-aryl-and 2-heteroaryl-benzoxazoles and benzothiazoles from Schiff bases by using catalytic amounts of Pd(OAc) 2 in imidazolium ILs (bmim)BF 4 and (bmim)PF 6 without ligands and/or additives has been reported (Scheme 7.22) [126]. The Cao Q et al approach (2011): 5-hydroxymethylfurfural (HMF) has been synthesized from fructose and glucose in the presence of various imidazolium ILS, including 1-butyl-3-methylimidazolium chloride (BmimCl), 1-hexyl-3-methylimidazolium chloride (HmimCl), 1-octyl-3-methylimidazolium chloride (OmimCl), 1-benzyl-3-methylimidazolium chloride (BemimCl), 1-butyl-2,3-dimethylimidazolium chloride (BdmimCl), and 1-butyl-3-methylimidazolium p-toluenesulfonate (BmimPS) (Scheme 7.24) [128]. Synthesis of 4,5-disubstituted oxazoles using ILs (Scheme 7.25) has been reported by Wu B et al [129].…”

Formation of a renewable amide, 3-acetamido-5-acetylfuran, via direct conversion of N-acetyl-d-glucosamine

“…In previous research, using fructose as the feedstock, 0% yield of 5-HMF was obtained in [BMMim]Cl whereas 63% yield was obtained in [BMim]Cl. 10 It has been proposed that the acidic protons on the imidazolium ring help to catalyze the dehydration reaction. In our studies using [BMMim]Cl, substitution of a methyl group at the C2 position removes the most acidic proton of the imidazolium cation.…”

“…A wide range of basic and acidic additives were studied (entries [4][5][6][7][8][9][10][11][12], and with the exception of boric acid, yields of 3A5AF of between 10 and 30% were obtained. Metal salts proved ineffective at increasing the yield of 3A5AF under the reaction conditions employed.…”