PhIO/Et3N ⋅ 3HF‐Mediated Formation of Fluorinated 2H‐Azirines via Domino Fluorination/Azirination Reaction of Enamines

A variety of enamine carboxylic esters and enaminones were converted to the biologically interesting fluorinated 2H‐azirines through reactions with PhIF2 generated in situ by PhIO and Et3N ⋅ 3HF in 1,2‐dichroloethane, which features the hypervalent iodine reagents‐mediated introduction of fluorine atom and formation of the 2H‐azirine skeleton under metal‐free conditions. The domino reaction is postulated to proceed via a PhIF2‐mediated oxidative fluorination and a subsequent azirination of the fluorinated enamine intermediates.