Chiral aziridine-2-carboxylates have two important functional groups, the carboxylate group and aziridine ring, that are useful for synthetic purposes. As both (2R)-and (2S)-aziridine-2-carboxylates were commercialized in optically pure forms, we have studied to extend their synthetic utilities for the construction of various nitrogen-containing molecules. The C2 ester group can be transformed into aldehydes, alcohols, amides, ketones, b-ketoesters, and amines bearing diverse substituents with defined stereochemistry in high yields. In particular, ring-opening reactions of aziridines are carried out in regio-and stereoselective manners toward a-or b-amino cyclic and acyclic compounds in optically pure forms. The highlight of this chemistry based on the regio-and stereoselective functional-group transformations of aziridine-2-carboxylates is exemplified by efficient and highly stereoselective syntheses of many biologically important amines, including natural products.