Sustainable valorization of biomass‐derived aromatics is essential for green chemical manufacturing. Palm oil mill effluent (POME), a major agro‐industrial wastewater, contains phenolic acids such as p ‐hydroxybenzoic acid ( p ‐HBA) that inhibit anaerobic digestion but represent valuable chemical feedstocks. Here, we demonstrate a scalable chemoenzymatic platform for selective iodination of p ‐HBA, vanillic acid (VA), and ferulic acid (FA) using pyranose 2‐oxidase (P2O) to generate hydrogen peroxide in situ under mild aqueous conditions. Buffer screening revealed that tris(hydroxymethyl)aminomethane hydrochloride, 4‐(2‐hydroxyethyl)‐1‐piperazineethanesulfonic acid, and sodium phosphate best promoted monoodination of p ‐HBA, VA, and FA, respectively. Compared to direct H 2 O 2 addition, P2O‐mediated oxidant supply improved selectivity for 3‐iodo‐ p ‐HBA (3‐IHBA) (15% vs. 21%), suppressed di‐iodination, and prevented oxidative coupling of FA. Liter‐scale reactions retained small‐scale efficiency, achieving >99% conversion and 93% yield for VA, and 89% conversion with 88% yield for FA. Moreover, direct conversion of POME‐derived p ‐HBA yielded 3‐IHBA (19%), confirming compatibility with real wastewater matrices. This work establishes P2O‐driven iodination as a mild, selective, and scalable route for synthesizing iodinated aromatics from waste‐derived phenolics, providing a green alternative to conventional halogenation and advancing sustainable biorefinery development.
Punthong et al. (Sun,) studied this question.