Metal-free dehydration of glucose to 5-(hydroxymethyl)furfural in ionic liquids with boric acid as a promoter

Autor:	Peter Fristrup, Anders Riisager, Tim Ståhlberg, Sergio Rodríguez-Rodríguez
Rok vydání:	2010
Předmět:	Sucrose Molecular Structure Organic Chemistry Ionic Liquids Fructose General Chemistry Furfural Catalysis Boric acid chemistry.chemical_compound Glucose chemistry Boric Acids Yield (chemistry) Ionic liquid Organic chemistry Hydroxymethyl Furaldehyde
Zdroj:	Chemistry (Weinheim an der Bergstrasse, Germany). 17(5)
ISSN:	1521-3765
Popis:	The dehydration of glucose and other hexose carbohydrates to 5- (hydroxymethyl)furfural (HMF) was investigated in imidazolium-based ionic liquids with boric acid as a promoter. A yield of up to 42 % from glucose and as much as 66 % from sucrose was ob- tained. The yield of HMF decreased as the concentration of boric acid exceed- ed one equivalent, most likely as a con- sequence of stronger fructose-borate chelate complexes being formed. Com- putational modeling with DFT calcula- tions confirmed that the formation of 1:1 glucose-borate complexes facilitat- ed the conversion pathway from glu- cose to fructose. Deuterium-labeling studies elucidated that the isomeriza- tion proceeded via an ene-diol mecha- nism, which is different to that of the enzyme-catalyzed isomerization of glu- cose to fructose. The introduced non- metal system containing boric acid pro- vides a new direction in the search for catalyst systems allowing efficient HMF formation from biorenewable sources.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7f0932888546fc80c41a5bd62d3a0eea https://pubmed.ncbi.nlm.nih.gov/21268148 Zobrazit plný text záznamu Plný text