Streamlined Synthesis of Biomonomers for Bioresourced Materials: Bisfuran Diacids, Diols, and Diamines via Common Bisfuran Dibromide Intermediates

A bisfuran dibromide has been established as the versatile and common intermediate for the high-yield synthesis of the three important classes of bisfuran monomers for furan-based renewable materials, bisfuran diacids, diols, and diamines. The general synthetic route involves a coupling reaction of 2-methylfuran with a ketone (acetone or cyclohexanone) under acidic conditions and a bromination reaction of the resulting bisfuran dimethyl compound to produce the bisfuran dibromide intermediate. This dibromide intermediate is subsequently converted to the corresponding bisfuran diacid (via oxidation reaction with KMnO₄ under basic conditions), bisfuran diol (by hydrolysis reaction under mild basic conditions), and bisfuran diamine (through the Gabriel reaction). The versatility of the bisfuran dibromide intermediate and the effective transformation into the monomers with high to quantitative yield typically without the need for further purification highlight the two attractive features and potential for large-scale production.