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.