Synthesis of Oxazolidinones from Epoxides and Isocyanates Catalyzed by Rare-Earth-Metal Complexes

Rare-earth-metal complexes stabilized by an amino-bridged triphenolate ligand showed high efficiency in catalyzing the cycloaddition of isocyanates and epoxides in the presence of NBu4I under mild conditions. This strategy is applicable to both terminal and disubstituted epoxides as well as various isocyanates, and tolerated different types of functional groups. Moreover, it is highly regio- and stereoselective, and afforded 3,5-disubstituted oxazolidinones as the only products in most cases in moderate to good yields.