Thermodynamically favorable protocol for the synthesis of 2-oxazolidinones via Cu(I)-catalyzed three-component reaction of propargylic alcohols, CO2 and 2-aminoethanols

Efficient CuI/1,10-phen-catalyzed three-component cascade reaction of propargylic alcohols, CO2, and 2-aminoethanols has been firstly developed for the thermodynamically favourable preparation of 2-oxazolidinones. In the presence of commercially available CuI, 1,10-phen (1,10-phenanthroline) and t-BuOK,the cascade reaction afforded the desired products in good to excellent yields with a broad substrate scope (14 examples). The predicted copper complex Cu2I2(phen)(2) in situ formed from CuI and 1,10-phen could activate the triple bond through coordination. The isolation of alpha-alkylidene cyclic carbonate as the reaction intermediate suggests that the carboxylative cyclization of propargylic alcohol with CO2, followed by ring-opening reaction, is involved in the one-pot three-component cascade reaction.