This review reports the applications of commercially available and custom-made organic carbonates as green media from laboratory to industrial scale applications.

2,5-furandicarboxylic acid (FDCA) is one of the most studied bio-based monomers, being considered the best substitute for fossil-derived terephthalic acid in plastic production. FDCA is employed in the preparation of polyethylene furanoate (PEF), demonstrating superior mechanical and thermal proprieties compared to the widely used polyethylene terephthalate (PET). Nevertheless, FDCA synthesis mostly relies on the oxidation of the bio-based platform chemical hydroxymethyl furfural (HMF), whose notoriously instable nature renders FDCA yield and industrial scale-up production complicated. On the contrary, FDCA esters are less studied, even though they have greater solubility in organic media, which would favor their isolation and potential application as monomers for PEF. On these premises, we report herein an alternative green synthetic approach to FDCA methyl ester (FDME) using galactaric acid as the substrate, dimethyl carbonate (DMC) as the green media, and Fe₂(SO₄)₃ as the heterogeneous Lewis acid. Optimization of the reaction conditions allowed the selective production of FDME in a 70% isolated yield; product purification was achieved via flash column chromatography over silica. Furthermore, it was possible to employ up to 5.0 g of galactaric acid in a single reaction, leading to a good isolated yield of FDME.

Commercially available Purolite CT151 demonstrated to be an efficient acid catalyst for the synthesis of alkyl levulinates via alcoholysis of furfuryl alcohol (FA) at mild temperatures (80–120 °C) and short reaction time (5 h). Reaction conditions were first optimized for the synthesis of ethyl levulinate and then tested for the preparation of methyl-, propyl-, isopropyl-, butyl, sec-butyl- and allyl levulinate. Preliminary scale-up tests were carried out for most of the alkyl levulinates (starting from 5.0 g of FA) and the resulting products were isolated as pure by distillation in good yields (up to 63%). Furthermore, recycling experiments, conducted for the preparation of ethyl levulinate, showed that both the Purolite CT151 and the exceeding ethanol can be recovered and reused for four consecutive runs without any noticeable loss in the catalyst activity.

The ultimate goal of biorefinery is to move away from a fossil‐based industry aiming to a more sustainable one centered on the use of renewable feedstocks. It is well known that numerous bio‐based platform chemicals can be obtained from biomass. Among them, 5‐hydroxymethylfurfural (HMF) and 2,5‐bis(hydroxymethyl)furan (FDCA) – achieved by HMF hydrogenation – are two of the most studied representatives. The etherification of these molecules with different alcohols yields 5‐(alkoxymethyl)furfurals (AMFs) and 2,5‐bis(alkoxymethyl) furans (BAMFs) respectively, both demonstrating potential application as fuel additives. In addition, HMF, when subjected to self‐etherification, leads to 5,5′‐[oxybis(methylene)]bis‐2‐furfural (OBMF), another bio‐based monomer of growing interest. In this work, a comprehensive investigation on the etherification of HMF and 2,‐5‐bis(hydroxymethyl)furan (BHMF) promoted by a commercially available ion exchange resin – Purolite CT275DR – is conducted using a continuous flow apparatus. The reaction conditions are optimized for the etherification of BHMF with ethanol and then extended to achieve a library of BAMFs. In addition, HMF etherification and self‐etherification are studied. HMF self‐etherification to form OBMF is conducted using dimethyl carbonate in the presence of both heterogeneous and homogeneous acid catalysts. Finally green metrics are calculated for the etherification of BHMF with ethanol and the values are compared to previously published procedures.