Conversion of Polyesters to Versatile Synthetic Subunits Enabled by Manganese-Catalyzed Transfer Semi-Hydrogenolysis with Ethanol.

The development of efficient chemical strategies for upcycling waste polyesters into value-added feedstocks is essential to advance a sustainable future. However, current approaches remain constrained by several issues, including harsh reaction conditions, a strong dependence on precious metals, incompatibility with real-world mixed plastic waste, and a narrow product utility. Herein, we report the first transfer semi-hydrogenolysis process that enables the conversion of polyesters into bifunctional molecules bearing both hydroxyl and ester groups. This method employs an earth-abundant manganese-based catalyst and uses biorenewable ethanol as both the alcoholysis reagent and hydrogen donor. Operating under mild and practical conditions, the system exhibits remarkable tolerance to various impurities commonly found in real polyester waste streams, such as other plastics, dyes, and fibers, while achieving a record-breaking turnover number for ester transfer hydrogenation. Furthermore, the resulting semireduced products are validated as versatile feedstocks for synthesizing bioactive compounds and functional materials.