Palladium(ii) complexes with planar chiral ferrocenyl phosphane–(benz)imidazol-2-ylidene ligands†
We describe here the first examples of planar chiral ferrocenyl phosphane–benzimidazol-2-ylidene ligands and their coordination chemistry with palladium(II). All ligand precursors, namely enantiopure ferrocenyl phosphane–(benz)imidazolium salts, and all enantiopure palladium complexes have been fully characterised by 1H, 31P and 13C NMR, mass spectrometry and X-ray diffraction methods for seven examples. The potential of these very bulky bidentate ligands in catalysis was evaluated and compared to their imidazol-2-ylidene analogues. The influence of sterics was shown to be non-negligible as the bulkiest ligand gave the lowest activities in the asymmetric Suzuki–Miyaura reaction.