The First Molecular Level Monitoring of Carbohydrate Conversion to 5‐Hydroxymethylfurfural in Ionic Liquids. B₂O₃—An Efficient Dual‐Function Metal‐Free Promoter for Environmentally Benign Applications

Abstract

The mechanistic nature of the conversion of carbohydrates to the sustainable platform chemical 5-hydroxymethylfurfural (5-HMF) was revealed at the molecular level. A detailed study of the key sugar units involved in the biomass conversion process has shown that the simple dissolution of fructose in the ionic liquid 1-butyl-3-methylimidazolium chloride significantly changes the anomeric composition and favors the formation of the open fructoketose form. A special NMR approach was developed for the determination of molecular structures and monitoring of chemical reactions directly in ionic liquids. The transformation of glucose to 5-HMF has been followed in situ through the detection of intermediate species. A new environmentally benign, easily available, metal-free promoter with a dual functionality (B(2)O(3)) was developed for carbohydrate conversion to 5-HMF.

Novel Catalytic Systems to Convert Chitin and Lignin into Valuable Chemicals

“…Boric acid was previously used in glucose/cellulose conversion as a promoter [51][52][53]. The formation of 1:1 glucoseborate complexes was confirmed by density functional theory (DFT) calculations, which facilitated the conversion pathway from glucose to fructose by decreasing the energy of intermediates.…”

Efficient Sustainable Tool for Monitoring Chemical Reactions and Structure Determination in Ionic Liquids by ESI‐MS

“…This sample corresponds to a real chemical system studied in the frameworks of developing of biomass conversion technologies. [10, 20, 23] Sample II is a solution of dipeptide Boc-Val-Ala-OMe in 1-ethyl-3-methylimidazolium chloride ([EMIM][Cl]), mimicking a typical system in peptide chemistry, which is a rapidly developing area of application of ionic liquids. [24]…”

“…[19, 9] Recently, our group has reported a special NMR approach for the determination of molecular structures and monitoring of chemical reactions directly in ionic liquids. [20]…”

Acid-Catalyzed Dehydration of Fructose to 5-(Hydroxymethyl)furfural

“…Due to the strong complexation between the boron atom and the hexoses, B(OH) 3 with various salts or B 2 O 3 alone were applied for fructose dehydration [123,124]. Interestingly, silicon was found to be a suitable semiconductor for fructose conversion to HMF compared with α-Fe 2 O 3 , WO 3 , and TiO 2 .…”