Zinc‐Catalyzed Stereo‐ and Regioselective 1,4‐Hydrative Fluorination of 3‐En‐1‐ynamides with Selectfluor

Zinc-catalyzed 1,4-oxofluorinations of 3-en-1-ynamides with Selectfluor in acetonitrile/water proceeded with high regio- and stereoselectivity, giving E-configured γ-fluoro-α,β-unsaturated amides efficiently. Our control experiments indicate that kinetically unstable C-bound zinc dienolates are chemically reactive to undergo SE2′-electrophilic fluorinations whereas the detectable O-bound dienolates preferably undergo protodemetalation reactions instead.