Asymmetric Radical Bicyclization of Allyl Azidoformates via Cobalt(II)-Based Metalloradical Catalysis

Cobalt­(II)-based
metalloradical catalysis has been successfully
applied to radical bicyclization of allyl azidoformates to construct
aziridine/oxazolidinone-fused bicyclic structures. The Co­(II) complex
of D2-symmetric chiral amidoporphyrin
3,5-DitBu-QingPhyrin has been identified
as an effective metalloradical catalyst for the intramolecular radical
aziridination of this type of carbonyl azides, allowing for high-yielding
formation of synthetically useful chiral [3.1.0]-bicyclic aziridines
with high diastereo- and enantioselectivity.