Chemical Upcycling of Waste Poly(bisphenol A carbonate) to 1,4,2‐Dioxazol‐5‐ones and One‐Pot C−H Amidation

Abstract Chemical upcycling of poly(bisphenol A carbonate) (PC) was achieved in this study with hydroxamic acid nucleophiles, giving rise to synthetically valuable 1,4,2‐dioxazol‐5‐ones and bisphenol A. Using 1,5,7‐triazabicyclo[4.4.0]‐dec‐5‐ene (TBD), non‐green carbodiimidazole or phosgene carbonylation agents used in conventional dioxazolone synthesis were successfully replaced with PC, and environmentally harmful bisphenol A was simultaneously recovered. Assorted hydroxamic acids exhibited good‐to‐excellent efficiencies and green chemical features, promising broad synthetic application scope. In addition, a green aryl amide synthesis process was developed, involving one‐pot depolymerization from polycarbonate to dioxazolone followed by rhodium‐catalyzed C−H amidation, including gram‐scale examples with used compact discs.