Cycloaddition of Aziridine with CO2/CS2 Catalyzed by Amidato Divalent Lanthanide Complexes

This is the first time that the amidato lanthanide amides ({LnLn[N(SiMe3)2]THF}2 (n = 1, Ln = Eu (1); n = 2, Ln = Eu (3), Yb (4); HL1 = tBuC6H4CONHC6H3(iPr)2; HL2 = C6H5CONHC6H3(iPr)2) and {L3Eu[N(SiMe3)2]THF}{L32Eu(THF)2} (2) (HL3 = ClC6H4CONHC6H3(iPr)2)) were applied in the cycloaddition reactions of aziridines with carbon dioxide (CO2) or carbon disulfide (CS2) under mild conditions. The corresponding oxazolidinones and thiazolidine-2-thiones were obtained in good to excellent yields with good functional group tolerance.