Atmospheric Pressure of CO2 as Protecting Reagent and Reactant: Efficient Synthesis of Oxazolidin‐2‐ones with Carbamate Salts, Aldehydes and Alkynes

Abstract

AbstractCarbon dioxide (CO2) has been wildly employed as an environmentally benign C1 resource for organic synthesis in the recent years. The capture of CO2 with primary amines easily provides the corresponding carbamate salts. We described herein that carbamate salts are a useful reactant for the synthesis of oxazolidin‐2‐ones via the reaction with aromatic aldehydes and aromatic terminal alkynes. A variety of oxazolidin‐2‐ones with different functional groups were synthesized in 68–91% yields with only a 5 mol% amount of CuI as catalyst. It was found that the synergetic effect of iodide is important for the transformation. Notable, the captured CO2 serves not only as a protecting reagent for electron‐rich primary amine to avoid catalyst poisoning, but also as a reactant for the construction of oxazolidin‐2‐ones.magnified image