Azidation of β-keto esters and silyl enol ethers with a benziodoxole reagent.

The efficient azidation of β-keto esters and silyl enol ethers using a benziodoxole-derived azide transfer reagent is reported. The azidation of cyclic β-keto esters could be achieved in up to quantitative yields in the absence of any catalyst. In the case of less reactive linear β-keto esters and silyl enol ethers, complete conversion and good yields could be obtained by using a zinc catalyst.