Synthesis of Oxiranes and Aziridines from Aldehydes and Imines Using Anionic Homologation Approaches

This chapter journeys through creative homologation contributions made in accessing oxiranes and aziridines from carbonyl and imine platforms beginning in the late 1800s to present times. Significant emphasis was placed on Darzens [2+1]-inspired annulations, with selected contributions in ylide and diazo chemistry following in later sections. Mechanistic analysis of selected strategies as well as applications to total synthesis are described.