Heteroarenecarbonyl Cinchona Alkaloid Catalyzed Enantioselective Desymmetrization of Aziridines with Phosphites

Nakamura et al. have developed the heteroarenecarbonyl cinchona alkaloid catalysts, N-(9-deoxy-epi-cinchonin-9-yl)picolinamide (1a) and N-(9-deoxy-epi-cinchonidin-9-yl)picolinamide (1b), and reported the enantioselective desymmetrization of aziridines with phosphites using 1. According to their results, various aziridines are converted into optically active β-aminophosphonic acids in high yields with high enantioselectivities by using 1 and Et₂Zn as catalysts. In this approach, both enantiomers are directly synthesized by using either 1a and 1b. Obtained optically active β-aminophosphonic acids and their derivatives can be used as biologically active substances and chiral ligands.