Perfluorinated rare earth metals catalyzed reactions of 5-methylene-2-oxazolidinone and 5-methylene-1,3-thiazolidine-2-thione with isocyanates

5-Methylene-2-oxazolidinone (1) and 5-methylene-1,3-thiazolidine-2-thione (2) can react effectively with various isocyanates to give the corresponding condensed urethanes in high yields in the presence of perfluorinated rare earth metal catalyst under mild conditions.