Nickel-Catalyzed Defluorophosphonylation of Aryl Fluorides

A Ni-catalyzed cross-coupling reaction between aryl fluorides and dialkyl phosphonates [HP­(O)­(OR)2] (R = secondary alkyl groups) in the presence of potassium tert-butoxide as a base is reported. The reaction converted various aryl fluorides into the corresponding aryl phosphonates even when electron-donating substituents were present on the aromatic ring. The combined experimental and computational studies suggested Ni–K+ cooperative action of a Ni(0) complex chelated with a strongly electron-donating ion-bridged dimeric phosphite ligand system [P­(OR)2O–K+]2 that facilitates turnover-limiting C–F bond oxidative addition of aryl fluorides.