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.