Continuous isomerisation of 2,5‐dimethylfuran to 2,4‐dimethylfuran over Ga‐silicate

Abstract

Abstract2,4‐dimethylfuran has a rare disubstitution pattern in the five‐membered heterocyclic furan ring that is highly interesting chemically but challenging to access synthetically. We present a heterogeneously catalysed route to synthesise 2,4‐dimethylfuran from commonly available 2,5‐dimethylfuran using a zeolite packed‐bed flow reactor. As supported by DFT calculations, the reaction occurs inside the zeolite channels, where the acid sites catalyse proton transfer followed by migration of a methyl group. The zeotype Ga‐silicate (MFI type) appears superior to an aluminium‐containing ZSM‐5 by demonstrating higher selectivities and slower catalyst deactivation. This work provides new opportunities for the continuous valorisation of bio‐feedstock molecules in the perspective of the emerging biorefinery era.