Efficient Fixation of CO2 at Atmospheric Pressure to N-propargylamines: Facile Method Promoted by Cu(I)-salts to Obtain 4-substituted-3-alkylideneoxazolidin-2-ones

The development of efficient methodologies for carbon dioxide (CO2) incorporation into value-added compounds remains a key objective in sustainable organic synthesis. Herein, we report the copper(I)-promoted synthesis of (Z)-3-benzyl-5-benzylidene-4,4-dimethyloxazolidin-2-one via coupling of propargyl amines with CO2 under mild conditions. Optimization studies revealed that CuI (1.0 equiv.) in DMF with NaOtBu as base affords the highest yield (90%) of the desired oxazolidinone while combination with palladium additives or using alternative copper sources such as CuBr or CuOAc proved ineffective. This example underscores the significant potential of copper in CO2 fixation chemistry and emphasizes the crucial role that both the nature and stoichiometry of the metal promoter play in governing the efficiency and selectivity of the transformation.