Synthesis of 2-Oxazolidinones: Palladium(II) ferrocenyl chalcogenide complex catalyzed Insertion of CO2 into Propargyl amines

Carbon dioxide is an abundant and renewable C1 building block for the synthesis of value-added chemicals. Herein, we report the catalytic carboxylative cyclization of propargylamines with CO₂ using palladium(II) ferrocenyl chalcogenide complexes. Selenium-containing complexes display superior catalytic activity compared to their tellurium analogues, affording 2-oxazolidinones in good to excellent yields under relatively mild conditions. The catalytic system tolerates a variety of propargylamine substrates and operates efficiently under low CO₂ pressure. Mechanistic studies suggest that the transformation proceeds via alkyne coordination to palladium, followed by CO₂ insertion and intramolecular 5-exo-dig cyclization, which was confirmed by NMR and mass spectral studies. These results highlight the potential of ferrocenyl palladium chalcogenide complexes as efficient catalysts for CO₂ fixation and the synthesis of valuable heterocyclic compounds.