Highly efficient epoxide carbonylation to β-lactones using a monophosphine cobalt acetyl complex

초록

The carbonylation of epoxides to β-lactones offers a direct and efficient pathway to valuable synthetic intermediates. However, the development of cost-effective and robust catalysts capable of delivering high turnover numbers (TONs) under mild conditions remains a significant challenge. In this study, a monodentate phosphine-ligated cobalt acetyl complex in combination with tetraphenyl porphyrin chromium(III) chloride (TPPCrCl), {[Co(acetyl)(CO)3(PPh3)]/[TPPCrCl]} (1), was optimized to catalyze epoxide carbonylation under mild conditions (30 °C, 1 bar CO), achieving > 99.9 % selectivity toward β-lactone formation. Under conditions of high substrate-to-catalyst ratios and elevated temperature, catalyst 1 exhibited exceptional stability and delivered a record TON of 195,600, demonstrating its strong potential for scalable β-lactone production.

키워드