In 2015,Ryan, Sarah J.; Schimler, Sydonie D.; Bland, Douglas C.; Sanford, Melanie S. published 《Acyl Azolium Fluorides for Room Temperature Nucleophilic Aromatic Fluorination of Chloro- and Nitroarenes》.Organic Letters published the findings.COA of Formula: C5H3BrClN The information in the text is summarized as follows:
The reaction of acid fluorides with N-heterocyclic carbenes (NHCs) produces anhydrous acyl azolium fluorides. With appropriate selection of the acid fluoride and NHC, these salts can be used for the room temperature SNAr fluorination of a variety of aryl chlorides and nitroarenes. E.g., in presence of N-heterocyclic carbene (I) and 4-MeOC6H4COF, fluorination of aryl chloride (II) gave 99% aryl fluoride (III). In the experiment, the researchers used 5-Bromo-2-chloropyridine(cas: 53939-30-3COA of Formula: C5H3BrClN)
5-Bromo-2-chloropyridine(cas: 53939-30-3) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. COA of Formula: C5H3BrClN