A novel synthetic route to optically active 1,3-oxazolidines via formal [3 + 2] cycloaddition in the presence of cinchona-alkaloid-thiourea-based bifunctional organocatalysts is reported. This protocol gives easy access to a wide range of chiral 1,3-oxazolidines. In addition, the results show that bifunctional organocatalysts can effect the intramolecular aza-Michael addition, leading to the asymmetric synthesis of nitrogen-containing heterocycles.