Dbf–ruthenocenes: Towards chiral halfsandwich Lewis acidic Dbf complexes

In order to develop a new class of chiral metallocene catalysts, halfsandwich ruthenocenes of dibenzo[c,g]fluorenide (Dbf−1) have been prepared. Structural and spectroscopic characterization of (η5-Dbf)Ru(PPh3)2Cl and [(η5-Dbf)Ru(PPh3)2(NCMe]+[SbF6]− provide evidence for strong metal–ligand binding in these sterically crowded complexes. In the solid state the complexes assume conformations ideal for transfer of the stereo information unto a prochiral substrate.