Catalytic Hydroxyethylation of Phenols with Renewable Ethylene Glycol Diester as an Alternative to Ethylene Oxide

Polyol esters are abundant bio‐based resources. Integration of polyol esters into the production chain of fine chemicals would reduce carbon emissions and improve the sustainability of the chemical industry. An efficient synthetic route to phenoxyethanols was developed through catalytic hydroxyethylation of phenols with ethylene glycol diacetate as the reagent. This method showed the potential of ethylene glycol diester as a safe and sustainable substitute for ethylene oxide, a useful but toxic reagent. A variety of phenoxyethanol esters were produced in high yield under simple catalytic conditions. Mechanistic studies revealed that the reaction underwent a neighboring group participation process. A Lewis acid‐catalyzed, solvent‐free hydroxyethylation strategy that converts phenols into phenoxyethanol esters is reported. Ethylene glycol diesters are used as renewable and safe alternatives to the harmful ethylene oxide. Oligomerization byproducts from ethylene oxide are also avoided. Applications are demonstrated in upcycling of polyester plastics and preparation of bioactive chemicals.