Defluorinative Functionalization of Pd(II) Fluoroalkyl Complexes

When subjected to arylboranes, anionic trifluoromethyl and difluorobenzyl palladium(II) complexes undergo fluoride abstraction followed by 1,1-migratory insertion. The resulting intermediate fluoroalkyl species can be induced to undergo a subsequent transmetalation and reductive elimination from either an in situ formed fluoroboronate (FB(Ar-3)(-)) or an exogenous boronic acid/ ester (ArB(OR)(2)) and nucleophilic activator, representing a net defluorinative arylation reaction. The latter method enabled a structurally diverse substrate scope to be prepared from either an isolated palladium-CF3 complex, or from Pd(PPh3)(4) and other commercially available reagents.