The discovery of huge petroleum reserves in the 19th century was a golden opportunity that promoted the industrial revolution, by offering a wide variety of cheap raw materials and a reliable source of energy. This caused an unprecedented increase of commodity and production of specialty chemicals in order to fulfill the needs of the global markets. However, as the global warming and the environmental issues has become a hazardous and worried situation, researchers are looking for bio renewable monomers with low toxicity in order to produce more sustainable polymers. This policy was also applied to epoxy resin materials because of their high volume production in industry for a wide range of applications. This review highlights the recent advances in the preparation of diamines and diepoxy monomers for the synthesis of epoxy resins, mainly from 2-furfural, 5-(hydroxymethyl)furfural (5-HMF), and 2,5-furandicarboxylic acid (FDCA), obtained from natural cellulose and hemicellulose feedstocks, respectively, and able to replace phthalic moieties in polyethylene terephthalate. In addition, the processes involved in the monomers preparation, such as reductive amination, etherification, esterification and carbonatation are listed. This review, reporting quasi-exhaustive synthetic pathways of epoxy precursors containing furanic moieties and describing the resulting resins, is composed of seven main parts, based on the synthesis of glycidyl derivatives containing one or two or four furan nuclei bearing or not a spacer between the furan ring and the function. The influence of the substituents on furan moieties (O, CO, CH 2 ) and the spacer between these groups have also been evaluated. Finally, thermal and a few mechanical properties of the obtained bio-sourced epoxy resins were compared to their fossil fuel analogues (from bisphenol A), featuring the high potential of bio-based monomers as substituents for non-renewable ones.
Ideally, a sustainable chemical synthesis should involve the use of non‐toxic solvents and reactants, easy separations and purification by energy‐efficient processes. In this context, reconsidering the synthesis of widely used drugs is especially timely and should allow important benefits to be obtained in terms of environmental impact. Sulfonamides are pertinent as their synthesis generally requires the use of toxic and/or hard‐to‐remove solvents such as dichloromethane, DMF and DMSO. In addition, toxic and highly reactive sulfur‐containing sources such as sulfonyl chloride are often involved and coupled with amines. Moreover, the latter may exhibit some toxicity and are generally difficult to purify. Herein, we disclose the unprecedented and sustainable synthesis of sulfonamides by using sodium sulfinate as a commercial and stable sulfur source and nitroarenes as the nitrogen‐containing reactant. In addition, under the optimized conditions only water is used as a “green” solvent and the products are collected by simple filtration.
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