Etherification of Bio-Based Furanic Compounds via Continuous Flow

Currently, the majority of energy is produced from oil, coal, and natural gas. Additionally, petroleumderived products account for the largest share of total final energy consumption. [1] This highlightsthe urgent need to reduce reliance on fossil fuels, in line with EU strategies aimed at tackling the growing challenges of plastic pollution, climate change, and sustainability. As a result, in 2007 the International Energy Agency (IEA), introduced the concept of Biorefinery (Task 42): "Biorefinery is the sustainable transformation of biomass into a wide range of commercial products (food, feed, chemical products) and energy (fuels, energy and heat)".[2] The ultimate goal of the biorefinery is the transition from a fossil-based model to a more sustainable industry focused on the use of renewable feedstocks, while adhering to the principles of the circular economy.[3] In this perspective, the socalled Bio-Based Platform Chemicals play an important role. Bio-Based Platform Chemicals are biomass derived molecules that incorporate one or more chemical moieties that can be easily functionalized so to lead to a library of derivatives for the most disparate applications i.e. biofuels, intermediates for the production of compounds of industrial interest and monomers for the synthesis of bio-based polymers.[4] From this premises, the presented work focuses on the functionalization of several furanic monomers easily derived from D-fructose. In particular, etherification of 5-hydroxymethylfurfural (HMF) and 2,5-bis(hydroxymethyl)furan (BHMF) via continuous-flow have been investigated so to synthetised 5,5 -[oxybis(methylene)]bis-2-furfural (OBMF) via HMF self-etherification ′ and a library of 2,5-bis(alkoxymethyl) furans (BAMFs), respectively. In both case studied, reaction conditions were optimized by evaluating the type and quantity of heterogeneous catalysts, the reaction media, as well as flow and temperature. In terms of possible applications BAMFs have demonstrated to be good additives for biofuels, meanwhile OBMF is generating increasing interest due to its exploitation in the synthesis of macrocycles (16-crown-6) and as a precursor of polyurethanes, polyamides, and polyamines.