(129e) Production of 5-Hydroxymethylfurfural From Glucose Using Water Compatible Lewis Acid Catalysts in a Biphasic Reactor with an Alkylphenol Solvent

The synthesis of 5-Hydroxymethylfurfural (HMF), a potential key biomass-derived platform chemical for the production of plastics, solvents, and transportation fuels, represents an important challenge in the economical utilization of lignocellulosic biomass.  We have demonstrated that in the presence of both homogeneous Lewis (e.g., AlCl₃) and Bronsted acids (e.g., HCl), glucose could first isomerize to fructose catalyzed by a Lewis acid salt and then the fructose could subsequently dehydrate to HMF catalyzed by a Bronsted acid. A biphasic system with an alkylphenol solvent, sec-butyl phenol (SBP) was used to continuously extract the HMF produced from the aqueous phase into the organic phase, thereby minimizing HMF degradation. With this multifunctional reaction systems design, high HMF yields (~60%) were achieved. While a low solution pH is required for most conventional Lewis acid salts such as aluminum to maintain their Lewis acidity in the presence of water, we will also discuss a serious of lanthanide metal salts could function as water-compatible Lewis acids under a wide range of pH values. Comparison of different lanthanide metal salts showed that decreasing glucose reactivity to HMF occurred with increasing ionic radii from Yb to Dy to La likely due to the larger cations having weaker electrostatic interaction with the glucose molecule.