Silica-catalyzed carboxylative cyclization of propargylic amines with CO2

By employing only silica as a catalyst, the carboxylative cyclization of a propargylic amine with CO2 proceeded to afford the corresponding 2-oxazolidinone. MCM-41, which was a mesoporous silica, was found to be the most effective silica for this purpose. Moreover, after the reaction, the MCM-41 catalyst was recovered by filtration and could be reused over ten times without deactivation. (C) 2020 Elsevier Ltd. All rights reserved.