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 H-1, P-31 and C-13 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.