Synthesis and Structural Characterization of Palladium Dicarbene Complexes Bearing Labile Co-Ligands
Dicarbene complexes [Pd(OAc)2(diNHC)] (2), [Pd(O2CCF3)2(diNHC)] (3), and [Pd(CNCH3)2(diNHC)](SO3CF3)2 (4) bearing labile acetato, fluoroacetato, and acetonitrile co-ligands have been synthesized via metathesis reaction of the respective precursor [PdBr2(diNHC)] (1) with Ag-salts. All complexes are stable towards air and moisture and have been fully characterized by spectroscopic and spectrometric methods. Notably and in comparison to diphosphine analogues, they resist ligand disproportionation in solution. Their molecular structures have also been determined by single crystal X-ray diffraction. A preliminary catalytic study showed low activity in the hydroamination reaction, but revealed an interesting co-ligand influence.