Azidation of β-Keto Esters and Silyl Enol Ethers with a Benziodoxole Reagent
作者:Maria Victoria Vita、Jérôme Waser
DOI:10.1021/ol401229v
日期:2013.7.5
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.
Detailed investigations concerning the organocatalytic (asymmetric) α-azidation of prochiral β-ketoesters were carried out. It was shown that the racemic version of such a reaction can either be carried out under oxidative conditions using TMSN₃ as the azide-source with quaternary ammonium iodides as the catalysts, or by using hypervalent iodine-based electrophilic azide-transfer reagents with different