Ruthenium Porphyrin Catalyzed Synthesis of Oxazolidin-2-ones by Cycloaddition of CO2 to Aziridines

The reaction between N-substituted-2-arylaziridines and CO2 is efficiently promoted by ruthenium(VI) imidoporphyrin complexes and yields a mixture of 5-aryl (A) and 4-aryl (B) substituted oxazolidin-2-ones with a regioisomeric A/B ratio up to 99:1. Several oxazolidin-2-one molecules were synthesized at 100 degrees C and 0.6 MPa of carbon dioxide by using the low catalytic loading of 1 mol-%. The formation of a deactivated compound, deriving from the ruthenium catalyst, suggested a possible catalytic role of imido nitrogen atoms.