24 Palladium in Heterocyclic Chemistry
Bromide is the most common leaving group but iodide and chloride can also be used, but for the last a more reactive
catalyst may sometimes be needed.
Non-aromatic (alkyl and alkenyl) boronates can also be used, but the corresponding trifl uoroborates (RBF 3 K) have
the advantages of better stability with consistent reactivity. Trifl uoroborates are easily prepared by reaction of boronic
acids with KHF 2.