Abstract
Aziridines are the smallest nitrogen-containing heterocycles and are responsible for
the biological activity of aziridine-natural products and active pharmaceutical ingredients
(APIs). Classically, aziridines are prepared from acyclic precursors via 1) [2+1]
cycloaddition of a nitrene equivalent with an olefin, 2) [2+1] cycloaddition of a
carbene equivalent with an imine, or 3) via intramolecular cyclization of β-functionalized
amines. In comparison, introduction of intact aziridines is an uncommon disconnection.
Here, we highlight the recent development of N-aziridinyl radicals as novel intermediates in synthetic chemistry that enable olefin
hydroxyaziridination. These intermediates, generated by photoredox activation of N-pyridinium aziridine precursors, afford access to products of a heretofore unknown
epoxide opening with N-aziridine nucleophiles and introduce new disconnections of olefin aziridination chemistry.
1 Introduction
2 Classical Aziridination Methods
3 Aziridine-Group Transfer
4 Conclusions
Key words
aziridines - olefin functionalization - nitrogen-centered radicals -
N-aminopyridinium salts
