Visible Light Photoredox Aziridination of Chalcones

Abstract

The aziridination of chalcones with iminoiodinanes under photoredox conditions has been reported. The reaction proceeds through nitrene radical anion intermediate generated from iminoiodinanes. The trapping of nitrene radical anions chalcones afforded trans‐aziridine products exclusively. The scope of the reaction in terms of both the substrates is considerably wide and in most of the cases trans‐3‐aryl‐aziridine‐2‐ketones were isolated in good yields. The reaction is challenging due to the electron‐deficient nature of the substrate, making this only the second example (after trifluoromethyl alkenes) of photocatalytic aziridination of electron‐deficient double bonds.

Copper(I)‐Photocatalyzed Diastereoselective Aziridination of N‐Sulfonyl Imines with Vinyl Azides: Application to Benzo[f][1,2,3]oxathiazepines Dioxides and Fused Isoxazolines

“…For instance, Zhou [12a] and Xuan's [12b] groups independently divulged simple light‐driven aza‐Darzens reactions involving N‐aryl glycines/hexahydro‐1,3,5‐triazines as the imines sources and diazo compounds either in the presence of photocatalyst or in its absence, respectively, producing a series of aziridines (Schemes 1a and 1b). Moreover, seminal studies by Yoon, [13a] Xu, [13b] Koenigs, [13c] and Rastogi [13d] groups chronicled efficient Ir(III)/Ru(II)‐photoredox catalyzed olefin aziridination reaction of alkenes with azidoformates/N‐protected aminopyridinium salts/iminoiodanes as the sources of nitrenes or N‐centered radicals for aziridine rings (Schemes 1c and 1d) [13] . However, Ir(III)/Ru(II)‐based photocatalysts are usually expensive, difficult to access and have low reduction abilities, which may deviate from their broad potential, practicality, and good scalability.…”