Abstract
<jats:p>The sustainable production of polymerizable aromatic monomers from renewable feedstocks is a key challenge toward reducing the reliance of the polymer industry on fossil resources. Herein, we report a biocatalytic platform for the efficient conversion of lignin-derived hydroxycinnamic acids into hydroxystyrene monomers suitable for further functionalization and polymer synthesis. A cofactor-independent ferulic acid decarboxylase from Bacillus pumilus (BpFDC) catalyzed the decarboxylation of ferulic, p-coumaric, caffeic, and sinapinic acids under mild conditions, affording the corresponding hydroxystyrenes in moderate to excellent yields. To improve catalyst recovery and process sustainability, the enzyme was covalently immobilized on superparamagnetic nanoparticles, enabling straightforward magnetic separation and reuse while maintaining catalytic activity over multiple cycles. Process intensification through a green anisole/buffer biphasic system significantly enhanced substrate loading and productivity, increasing the space–time yield from 0.54 to 7.4 g L-1 h-1 while facilitating product isolation and solvent recycling. The obtained 4-vinylguaiacol was subsequently functionalized via O-(hydroxyethyl)ation using bio-derived ethylene carbonate as a benign alkylating agent, affording a renewable bifunctional monomer suitable for further polymerization or post-polymerization modifications. Overall, this chemo-enzymatic strategy combines renewable feedstocks, recyclable biocatalysts, green reaction media, and waste-minimizing process design to provide a sustainable route toward functional bio-based styrene-derived building blocks for advanced polymeric materials.</jats:p>