Catalytic Carbonylation Of Biomass Furfural And Its Derivatives

With the depletion of fossil energy,the energy crisis is incresingly serious,and the exploration of renewable energy is urgent.Mountains of gold and silver are unworthy as clear waters and green mountains.Developing new renewable energy and resources has become an important goal of contemporary scientists.The advantages of a wide range of biomass sources,large reserves,renewable and non-pollution environment attract the attention of scientists all over the world.C6 5-hydroxymethylfurfural is a star molecule of biomass platform molecules and has a bright market potential.Carbon-based（C1）chemical technology has been highly valued by academia and industry,and has become an important research direction in current energy chemistry and green chemistry.C5furfural is a biomass platform molecule that has been industrialized.Using palladium with the reputation of“universal catalyst”as a catalyst,develop a green,sustainable and industrial application route to use C1 resources to achieve C5 molecular platform to C6molecule.The flat construction provides a feasible route for the final step of industrialization of the application of biomass resources.Biomass-based 2,5-furandicarboxylic acid（FDCA）is considered to be a great alternative to terephthalic acid in the polymer industry.Although it can be produced by catalytic oxidation of 5-hydroxymethylfurfural（HMF）,HMF itself is currently derived from monosaccharides and polysaccharides such as glucose and fructose,which are limited in yield,thus blocking the utilization of FDCA to replace p-phthalic acid as monomer in industrial applications.This work provides a new way to synthesize FDCA based on derivatives of self-renewable biomass furfural.This chapter mainly synthesizes FDCA by homogeneous catalyzed hydroxycarbonylation of 5-bromofuranoic acid in organic solvents to achieve HPLC analysis>99%.The FDCA yield achieved an isolated yield of greater than 90%in the gram reaction.The effects of palladium sources,phosphine ligands and bases were investigated in detail,and possible catalytic mechanisms were proposed.Although the activity of homogeneous catalysis is high,it is unfavorable for the recycling of the catalyst and the separation and purification of the product.This chapter provides a new way to synthesize C6 molecule 5-formyl-2-furancarboxylic acid（FFCA）from the renewable C5 molecular furfural-derived 5-bromofurfural in a water-oil two-phase system,and achieves the conversion of a mono-functional group furfural to multi-functional groups of products,so,thus opens up its potential market in polymeric applications.Under the optimized conditions,up to 99%FFCA yield is provided by the new catalysis hydroxycarbonylation in dual phase.It is worth noting that in the two-phase system,the aqueous phase is an alkaline environment to neutralize the acid generated by the catalytic cycle,so the resulting target product FFCA forming of a carboxylate enters the aqueous phase.Effectively achieving the separation from the material and the catalyst gave an isolated yield of 95%in a gram-level reaction.Currently,FFCA is an unstable intermediate in the oxidation of hydroxymethylfurfural（HMF）to obtain FDCA.In the industry,it is possible to obtain furfural from agricultural and forestry waste.This method based on catalytic hydroxycarbonylation to form FFCA is a downstream product of furfural,and it provides an opportunity for its production in large scale.Activated carbon（AC）is widely used as a supporter for heterogeneous catalysts because of its large surface area,excellent adsorption performance,high chemical stability,and low cost.Bio-based activated carbon was used as the supporter,the synthesized（Pd/XantphosCl₂）/AC as the catalyst,the biomass platform molecular furfural derived 5-bromo-2-decanoic acid as the substrate,gas CO as the carbonyl source in the water,achieving a yield of>99%of FDCA.The catalyst insolubilized in water can be recovered by simple centrifugation,and the activity and selectivity of the catalyst remain unchanged after 10 runs of catalytic recycling.The synthesis of furoic acid to5-bromofuroic acid had been realized in the industry.The work of this chapter not only develops the downstream products of bio-based C5 platform molecular furfural,but also opens up the market for furfural,and also provides a feasible method industrialized use of C1 resources for synthesis C6 molecular platform FDCA with great industrially application prospects.