Facile Synthesis of 2-Bromo-3-fluorobenzonitrile:  An Application and Study of the Halodeboronation of Aryl Boronic Acids

A scaleable synthesis of 2-bromo-3-fluorobenzonitrile via the NaOMe-catalyzed bromodeboronation of 2-cyano-6-fluorophenylboronic acid was developed. The generality of this transformation was demonstrated through the halodeboronation of a series of aryl boronic acids. Both aryl bromides and aryl chlorides were formed in good to excellent yields when the corresponding aryl boronic acid was treated with 1,3-dihalo-5,5-dimethylhydantoin and 5 mol % NaOMe.