Hybrid polyoxometalate palladacycles: DFT study and application to the Heck reaction

The phosphovanadotungstate polyanion [P₂W₁₅V₃O₆₂]^9? is a powerful support to stabilize palladacycles conjugated to the inorganic framework via an organic ligand. The insertion can be directed toward sp² or sp³ C–H insertion upon appropriate choice of the substitution pattern on the organic ligand. DFT modeling indicates that the strong withdrawing effect of the POM transmitted through the conjugated carbonyl was responsible for this easy insertion. The palladacycles led to the formation of stilbene via a Mizoroki–Heck reaction. However it is likely that the POMs act as Pd-reservoirs for the formation of nanoparticles.