Radical Nitration-Debromination of α‑Bromo-α-fluoroalkenes as a Stereoselective Route to Aromatic α‑FluoronitroalkenesFunctionalized Fluorinated Building Blocks for Organic Synthesis

A new highly efficient
method for the synthesis of 2-fluoro-2-nitrostyrenes
was described. Radical nitration of readily available 2-bromo-2-fluorostyrenes
with Fe­(NO3)3·9H2O resulted
in the formation of the corresponding α-fluoro-nitroalkenes
in isolated yields up to 92%. The reaction proceeded as a nitration-debromination
sequence to highly stereoselectively give α-fluoro-nitroalkenes
as Z-isomers only. The broad scope of this method
was demonstrated. Prepared monofluorinated alkenes were shown to be
versatile building blocks for the synthesis of various fluorinated
products.