Asymmetric α‐Azidation Reaction of β‐Ketoesters Catalyzed by Chiral Tin Alkoxides

Abstract

AbstractA catalytic enantioselective α‐azidation reaction of β‐ketoesters with an azidated hypervalent iodine reagent was achieved by using an (R)‐BINOL‐derived chiral tin dibromide possessing 4‐t‐butylphenyl groups at the 3‐ and 3’‐positions as the chiral precatalyst in the presence of sodium ethoxide and ethanol. Optically active α‐azido‐β‐ketoesters having a chiral tertiary carbon were obtained in moderate to high yields under the influence of the chiral tin diethoxide generated in situ.