biostudies-literatureKulyabin PSUKRI Future Leaders Fellowshipe21838https://www.ebi.ac.uk/biostudies/studies/S-EPMC12850997biostudies-literatureUnknown65(5)We report here the upcycling of PET (polyethylene terephthalate) waste via semihydrogenation to make ethyl 4-(hydroxymethyl)benzoate. The reaction is catalyzed by a ruthenium pincer catalyst at 80 °C in bioderived solvents - a combination of 2-methyl THF and ethanol. A detailed mechanistic investigation through organometallic and kinetic studies, as well as chemical exchange saturation transfer (CEST) NMR spectroscopy, provides insights into the nature of active species and factors that promote and inhibit the catalytic hydrogenation of PET. Using this mechanistic knowledge, a record high turnover number of >30 000 was achieved for the hydrogenative depolymerization of end-of-life PET waste (e.g., bottles and textiles). The semihydrogenation product, ethyl 4-(hydroxymethyl)benzoate, was utAngewandte Chemie (International ed. in English)From Plastic Waste to Pharmaceutical Precursors: PET Upcycling Through Ruthenium Catalyzed Semi-Hydrogenation.PMC12850997MR/W007460/1Marcial-Hernandez RPancholi KCordes DBKulyabin PSLuk JPidko EAUslamin EAMcKay APKuhne BKolganov AADauth ASaini GKumar AfalseFrom Plastic Waste to Pharmaceutical Precursors: PET Upcycling Through Ruthenium Catalyzed Semi-Hydrogenation.We report here the upcycling of PET (polyethylene terephthalate) waste via semihydrogenation to make ethyl 4-(hydroxymethyl)benzoate. The reaction is catalyzed by a ruthenium pincer catalyst at 80 °C in bioderived solvents - a combination of 2-methyl THF and ethanol. A detailed mechanistic investigation through organometallic and kinetic studies, as well as chemical exchange saturation transfer (CEST) NMR spectroscopy, provides insights into the nature of active species and factors that promote and inhibit the catalytic hydrogenation of PET. Using this mechanistic knowledge, a record high turnover number of >30 000 was achieved for the hydrogenative depolymerization of end-of-life PET waste (e.g., bottles and textiles). The semihydrogenation product, ethyl 4-(hydroxymethyl)benzoate, was ut2026-01-01T00:00:00Z2026 Jan2026-06-11T05:38:01.161Z2026-06-11T03:08:28.806ZS-EPMC128509974141019310.1002/anie.202521838