Nucleophilic Attack on Coordinated Imines: The Synthesis of C-Bonded Acetylacetonates of Palladium(II) and Mechanistic Insights

The reactivity of complexes [PdCl2(?2-NN')] [NN' = 2-C5H4N-CH=N-Ar; Ar = 2-MeC6H4, a; 4-MeC6H4, b; 2-MeOC6H4, c; 4-MeOC6H4, d; 4-CF3C6H4, e; 2,6-Me2C6H3, f; 2-iPrC6H4, g] and [Pd(?2-acac)(?2-NN')][BF4] toward the nucleophilic reagent acetylacetonate (acac) has been explored. This reaction starts with nucleophilic attack on the cabonylic atom of the coordinated imine generating a new CC bond and an amido complex. The next step in the reaction is proton migration leading to the protonation of the amido nitrogen, and finally replacement of this coordinated nitrogen atom with an anionic carbon atom. The final consequence of the nucleophilic attack on the coordinated imines is the formation of new complexes and the generation of new CC and CPd bonds.