Novel Brønsted–Lewis acidic di-cationic ionic liquid for efficient conversion carbohydrate to platform compound

A series of Brønsted–Lewis acidic di-cationic ionic liquids ( BLAILs ) were synthesized and the catalytic properties of glucose conversion to 5-hydroxymethylfurfural (5-HMF) were investigated. The experimental results showed that the ionic liquid with aluminum trichloride as Lewis acid anion ( BLAIL - 5 ) exhibited good catalytic performance. Under the best reaction conditions, the yield of the glucose conversion into 5-HMF and 5-EMF were 71% and 66%, respectively. In addition, the yield of cellulose to 5-HMF is 41%. The optimized catalytic system could be reused for 5 times without significant catalytic performance loss. In addition, the mechanism of BLAIL - 5 promoting glucose conversion to 5-HMF was studied by density functional theory calculation (DFT).