A Metal-Free Synthesis of N-Aryl Oxazolidin-2-Ones by the One-Pot Reaction of Carbon Dioxide with N-Aryl Aziridines

The cost-effective TPPH2/TBACl-catalyzed (TPPH2=dianion of tetraphenyl porphyrin; TBACl=tetrabutyl ammonium chloride) carbon dioxide cycloaddition to N-aryl aziridines was successful in synthesizing N-aryl oxazolidin-2-ones. A catalytic tandem reaction was also developed, in which N-aryl aziridines were initially synthesized and then reacted with carbon dioxide without being purified. The procedure occurred with a very high atom economy, molecular nitrogen being the only by-product of the entire tandem process. In addition, the mechanism of catalytic cycle was investigated by DFT calculations. (Figure presented.).