Pd-Catalyzed ortho-Acylation of Acetanilide with Aldehyde through Direct C-H Bond Activation

Wang and Li et al. have reported a Pd catalyzed direct ortho-acylation of acetanilides with aldehydes affording the o-acyl acetanilides. In this study, Pd(OCOCF₃)₂ gave the best result as a Pd catalyst for the coupling reaction in the presence of tert-butyl hydroperoxide. They have proposed that it is effective to form the palladacycle intermediate when a highly cationic Pd(II) species, Pd(OCOCF₃)₂ is used;" it easily dissociates into a trifluoroacetate anion and a cationic Pd(II) species compared with that of Pd(OAc)₂.