Non-innocent additives in a palladium(II)-catalyzed C-H bond activation reaction: insights into multimetallic active catalysts.

The role of a widely employed additive (AgOAc) in a palladium acetate-catalyzed ortho-C-H bond activation reaction has been examined using the M06 density functional theory. A new hetero-bimetallic Pd-(μ-OAc)3-Ag is identified as the most likely active species. This finding could have far-reaching implications with respect to the notion of the active species in palladium catalysis in the presence of other metal salt additives.