In 2009, Buchwald group demonstrated the first catalytic nucleophilic fluorination to aryl fluorides in the presence of Pd-catalyst based on tBuBrettPhos with CsF as a fluoride source. Based on the significant report, the palladium-catalyzed nucleophilic fluorination system has been modified to improve the reactivity. Additionally, some groups reported the Cu-mediated and -catalyzed nucleophilic fluorination, wherein the reactions are considered to involve the formation of Cu(III) intermediates.