Chemical Upcycling of Waste Poly(bisphenol A carbonate) to 1,4,2‐Dioxazol‐5‐ones and One‐Pot C−H Amidation
Hyun Jin Jung, Sora Park, Hyun Sub Lee, Hyun Gyu Shin, Yeji Yoo, Ek Raj Baral, Jun Hee Lee, Jaesung Kwak, Jeung Gon Kim
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.