Isosorbide: Recent advances in catalytic production

This article focuses on the state-of-the-art advancements on the production of isosorbide, a furanic diol exclusively produced via a two-steps dehydrocyclisation of sorbitol; polyol acquired from the catalytic reduction of glucose. Generally, the compound is formed admixed with various types of monocyclic ethers called sorbitans. During the past half century, many researchers tried to explore the underlying mechanistic and kinetic aspects of the reactions involved in its formation with the main objective to increase the selectivity thus avoiding the formation of 2,5-sorbitan by-product. In the intervening years, new energy-saving and environmental-friendly methods have been developed, especially those that involve heterogeneous catalysts or acidic ionic liquids. In order to improve the catalytic activities of catalysts, it is imperative to measure the impact of their intrinsic acidity strength, porosity and surface hydrophobicity on each stage of the formation of bicyclic furanic compound. Additionally, comparative advantageous features of simple protocols involving acidic deep eutectic solvent employed as catalyst in solvent-free microwave-assisted reaction, are highlighted.