An efficient and recyclable AgNO3/ionic liquid system catalyzed atmospheric CO2 utilization: Simultaneous synthesis of 2-oxazolidinones and α-hydroxyl ketones

Oxazolidinones and α-hydroxyl ketones are two series of fine chemicals that have been generally utilized in biological, pharmaceutical, and synthetic chemistry. Herein, a AgNO 3 /ionic liquid (IL) catalytic system was developed for the simultaneous synthesis of these compounds through the atom-economical three-component reactions of propargyl alcohols, 2-aminoethanols, and CO 2 . Notably, this system behaved excellent catalytic activity with the lowermost metal loading of 0.25 mol%. Meanwhile, it is the first reported metal-catalyzed system that could efficiently work under atmospheric CO 2 pressure and be recycled at least five times. Evaluation of the green metrics proved the AgNO 3 /IL-catalyzed processes to be relatively more sustainable and greener than the other Ag-catalyzed examples. Further mechanistic investigations revealed the derivative active species of N-heterocyclic carbene (NHC) silver complexes and CO 2 adducts generated during the process. Subsequently, their reactivity in this reaction was assessed for the first time, which was finally identified as beneficial for the catalytic activity.