Synthesis of 2,5-furandicarboxylic acid by catalytic carbonylation of renewable furfural derived 5-bromofuroic acid

2,5-Furandicarboxylic acid (FDCA) is regarded as a biomass based alternative to p-phthalic acid in polymer industry. Although it can be produced through catalytic oxidation of hydroxylmethyl furfural (HMF), HMF itself is currently produced in limited volume from mono- and polysaccharides like glucose and fructose, thus blocking the utilization of FDCA to replace p-phthalic acid as monomer in industrial applications. This work presents an alternative route for FDCA synthesis originally from renewable furfural through carbonylation of 5-bromofuroic acid with common palladium catalysts, which achieves > 99% yield of FDCA based on HPLC analysis, or above 90% isolated yield in gram scale. The influences of the palladium sources, phosphine ligands and bases were investigated in details, and a simplified mechanism was also presented.