The use of aziridinium ions in two different projects is described. First, the stereospecificity of the ring opening of aziridinium ions with MeNH2 as a route to chiral diamines has been explored. When the aziridinium ion contained a phenyl or para-methoxyphenyl substituent, stereospecific ring opening occurred. In contrast, switching the para-methoxy group to a para-N,N-dimethylamino group gave a racemic diamine product. Second, starting from N-Boc pyrrolidine, asymmetric lithiation-trapping-ring expansion (via an aziridinium ion) was used to synthesise a piperidine alcohol. In this way, a formal synthesis of (−)-swainsonine was completed.
Oxenford, S. J., Moore, S., Carbone, G., Barker, G., O'Brien, P., Shipton, M. R., Gilday, J., & Campos, K. R. (2010). Asymmetric synthesis via aziridinium ions: exploring the stereospecificity of the ring opening of aziridinium ions and a formal synthesis of (−)-swainsonine. Tetrahedron: Asymmetry, 21(11-12), 1563-1568. https://doi.org/10.1016/j.tetasy.2010.03.048