Fluorocyclization of N-Propargylamides to Oxazoles by Electrochemically Generated ArIF2.
John D HerszmanMichael BergerSiegfried R WaldvogelPublished in: Organic letters (2019)
A sustainable synthesis of 5-fluoromethyl-2-oxazoles by use of electrochemistry has been demonstrated. Hypervalent ArIF2 is generated by direct electrochemical oxidation of iodoarene ArI in Et3N·5HF and mediates the fluorocyclization of N-propargylamides to 5-fluoromethyl-2-oxazoles. The stoichiometry in ArI turned out to be a key parameter in controlling the product selectivity. This electrochemical protocol provides access to fluorinated oxazoles starting from simply available N-propargylamides with yields up to 65% and offers a green alternative over conventional reagent-based approaches.