Effect of organic solvent and Brønsted acid on 5-hydroxymethylfurfural preparation from glucose over CrCl₃

Abstract

In the present work, the influence of organic solvent on the mechanism of 5-hydroxymethylfurfural (HMF) preparation from glucose over CrCl 3 and the role of Brønsted acid (N-methyl-2-pyrrolidone hydrogen sulfate ([NMP]HSO 4 ), N-methyl-2-pyrrolidone bromide ([NMP]Br), N-methyl-2-pyrrolidone chlorine ([NMP]Cl), H 2 SO 4 , HBr and HCl) during the reaction were researched by a complementary computational and experimental study. It was found that dimethyl sulfoxide (DMSO) gave the lowest conversion of glucose by surrounding CrCl 3 , forming a six-coordinated structure (CrCl 3 -3DMSO). Glucose conversion in N,N-dimethylformamide (DMF) was not selective. N,N-Dimethylacetamide (DMA) and n-butyl alcohol exhibited superior selectivity towards HMF from glucose. Then the role of different Brønsted acids in DMA was expounded. On increasing the dosage of [NMP]HSO 4 , glucose conversion decreased. A computational study found that HSO 4 À could also combine with CrCl 3 , forming six-coordinate complexes. Addition of [NMP]Br and [NMP]Cl accelerated the generation of HMF significantly but didn't increase the yield. An experimental method preliminarily confirmed that they were mainly responsible for fructose dehydration to HMF. A subsequent computational study further verified that the two kinds of ILs had no effect on glucose isomerization.Scheme 1 Mechanism of glucose isomerization to fructose catalyzed by Cr 3+ complex in DMA ([Cr 3+ ] represents different complexes of Cr 3+ and anions or DMA).This journal is

Interactions of d-cellobiose with selected chloride salts: A 13C NMR and FT-IR study

“…The theoretical calculations could also be used to elucidate the interactions between carbohydrates and metal ions. Nevertheless only a few studies are reported in the literature, which include the molecular dynamics studies on Na +glucose interactions [26], computational evidence for the complex formation between Cr 3+ [27], and Cr 2+ [28] with glucose. Furthermore, only a handful of studies have attempted to address the mechanisms of metal promoted depolymerization and dissolutions of cellulose [29].…”

Dehydration of glucose to 5-hydroxymethylfurfural and 5-ethoxymethylfurfural by combining Lewis and Brønsted acid

“…1,2 In comparison with other sugars, glucose is the most abundant hexose contained in lignin biomass, considered as the most valuable bio-derived carbon resource, and it plays a vital role in the conversion of biomass to biofuels and chemicals. [3][4][5] Thus, the high-efficiency transformation of glucose to platform chemicals has aroused much attention in recent years. 6 Among those prospective chemicals, HMF and EMF are thought highly of as promising building blocks for the application of renewable resources.…”

“…In Yan's work, CrCl 3 showed excellent catalytic efficiency in the conversion of carbohydrates. 34 But as it known to us, Cr belongs to heavy metal and do harm to the environment with some toxicity. Recently, via the good deal of work of Yu Yang and Hu, Li, AlCl 3 $6H 2 O was also proved to be a preeminent catalyst in the production of EMF, high yield with expectation achieved.…”

“…35,36 Both HMF and EMF are the vital platform chemicals in the conversion of carbohydrates, of which is worthy studied in depth, furthermore, EMF was obtained in the further ether-ication of HMF. [14][15][16][17][18][19][20][21]24,25,[27][28][29][30][31][32][33][34][35][36] And the study of direct conversion from glucose to EMF is particularly deserved. Thus, in this study, the dehydration of glucose to HMF was investigated by regulating reaction times, temperatures and the ratio of deionized water to organic solvent, some valuable chlorides (FeCl 3 $6H 2 O, SnCl 4 $5H 2 O, CrCl 3 $6H 2 O, etc.)…”

Conversion of carbohydrates into 5-hydroxymethylfurfural in an advanced single-phase reaction system consisting of water and 1,2-dimethoxyethane

“…1,2 5-Hydroxymethylfurfural (HMF), a dehydration product of C 6 carbohydrates, is one of the 10 most value-added bio-based platform chemicals, as it can be used in the synthesis of chemicals and liquid fuels. 6 HMF production from glucose mainly comprises two steps, namely, isomerization of glucose to fructose and dehydration of fructose to HMF. Production of HMF using fructose as feedstock has high yield, but the limited sources and high price of fructose restrict the large-scale application of this process.…”