BUILDING A LIBRARY OF FURANICS IN GRAM SCALE

5-Hydroxymethylfurfural (HMF) - considered an archetype of bio-based platform chemicals[1] - can be easily prepared from D-fructose via triple dehydration catalysed by different types of acid catalysts including mineral and Lewis acids, metal chlorides, metal oxides, heteropolyacids and ion-exchange resins, etc.[2] Main drawbacks of this synthetic approach include harsh reaction conditions and difficult isolation of the target molecule from the reaction media. Furthermore, most of the syntheses leading to HMF - and in general furanics - are conducted on small scale reactions where separation and isolation strategies are rarely addressed. In our research group we are interested in investigating the synthesis and the subsequent upgrade of HMF - and other bio-based platform chemicals - into a variety of value-added derivatives, such as chemicals, fine chemicals, materials, bio-based polymers and fuels. In this prospect it is essential to develop simple gram scale synthetic approaches addressing both isolation and purification of these compounds. In recent years we have investigated gram scale syntheses of HMF,[3] 5-bis(hydroxymethyl)furan (BHMF), 2,5-bis[(alkoxycarbonyl)oxymethyl]furan (BAMF),[4] 2,5-Bis[(alkoxycarbonyl)oxymethyl] furan (BCMF)[5], 2,5-furandicarboxylic acid dimethyl ester (FDME)[6] and 5,5 '(oxy-bis(methylene)bis-2-furfural (OBMF) and its derivatives.[7] Most of the abovementioned compounds have been achieved employing commercially available catalysts, green solvents, mild reaction conditions and the products were isolated as pure via simple purification procedures. Besides in some cases the related green metrics have also been investigated.