Copper/Iron Cocatalyzed Depolymerization of Postconsumer Polycarbonate: A One-Pot Strategy to Synthesize Aryl Ethers

Abstract

The synthesis of value-added chemicals from plastic waste, which poses a significant environmental threat, is both intriguing and challenging. Consequently, developing new methods for the depolymerization of plastic has become essential due to its increasing demand and usage. In this context, we have developed a base-driven, Cu/Fe-cocatalyzed depolymerization method for polycarbonates (PC), transforming them into diaryl ether and diaryl diethers in a one-pot process. This methodology exclusively utilized postconsumed real-life PCs. By varying reaction parameters, we successfully utilized PC as a nucleophile source to produce a range of products including diaryl ethers and diaryl diethers. A wide array of aryl halides and PCs with molecular weights ranging from 86,000 to 20,000 were screened using this approach. Gram-scale reactions underscored the potential and scalability of ether synthesis. The synthetic utility of the obtained ethers was further explored, leading to the synthesis of diverse value-added products. NMR experiments revealed that the depolymerization of PCs is driven by the base, which subsequently generates potassium diphenolate for cross-coupling with aryl halides in the presence of the Cu/Fe cocatalytic system.