Silver-catalyzed carbon dioxide incorporation into propargylic amides

A method for the synthesis of oxazolidine-2,4-diones by silver-catalyzed CO2 incorporation into propargylic amides under base-free mild reaction conditions was developed. These conditions were applied to a variety of aryl- and alkyl-substituted propargylic amides to afford the corresponding oxazolidine-2,4-diones in high yields. Combined with iodination during the CO2 incorporation reaction, the present reaction was successfully applied to the synthesis of the pesticide pentoxazone.