Photocatalytic Generation of Nitrenes for Rapid Diaziridination

A blue LED, an organic photocatalyst
(rose bengal), and the Lewis
acid like oxidant PhI­(OAc)2 were utilized to generate nitrene
intermediates through reactions of 1,2-diols and aliphatic amines
under mild reaction conditions. A versatile and rapid diaziridination
strategy was established to construct functionalized 1,2-disubstituted
diaziridines, diaziridines with chiral substituents, and 1,2,3-trisubstituted
analogues with excellent reaction rates, yields, and stereoselectivities.
Control and labeling experiments to elucidate the mechanism of this
elegant metal-free photocatalyzed cyclization reaction were performed.