A Library of Versatile Lignocellulose‐Derived Monomers From 5‐(Chloromethyl)furfural

The valorization of biomass‐derived platform chemicals into functional monomers is a promising strategy for developing more sustainable polymeric materials. Herein, we report a versatile synthetic approach for the preparation of a library of lignocellulosic (LC) monomers by coupling 5‐(chloromethyl)furfural (CMF), once considered a waste product of furan production, with selected lignin‐derived monomers. The reaction was optimized using vanillin, affording a bis aldehyde monomer (Fur‐Van) in 93% yield after only 2 h under mild conditions using K 2 CO 3 as the base. The methodology was successfully extended to a range of lignin‐derived substrates bearing different functional groups, providing a library of LC monomers in up to 94% isolated yield. The reactions were also successfully scaled up to 5 g of CMF. Products were isolated without any chromatographic purification. Furthermore, the reduction of the carbonyl groups afforded the corresponding (di)ol monomers in 87%–98% yield. Thermal characterization revealed good thermal stability of the synthesized compounds, with degradation temperatures above 220 °C for all the LC monomers. Overall, this work provides a straightforward and scalable route to multifunctional bio‐based monomers combining lignin‐derived aromatic structures with furanic moieties, offering promising building blocks for the development of bio‐based polymeric materials.