Chiral Mono- and Bis-annelated Cyclopentadienyl Ligands Derived from Tartaric Acid: Synthesis of [(η5-Cyclopentadienyl)RuCl(cod)] and [(η5-Cyclopentadienyl)(η6-benzene)Ru]PF6 Derivatives

The synthesis of chiral mono- and bis-annelated 1,3-cyclopentadienes derived from tartaric acid, a chiral pool starting material, is described. In addition to known functionalized chiral 1,3-cyclopentadienes, new derivatives have also been structurally characterized by X-ray crystallographic and NMR spectroscopic studies. Neutral and cationic ruthenium(II) complexes, containing a mono-annelated chiral cyclopentadienyl ligand (1), have been successfully prepared. The X-ray crystal structure of [(η5-Cp‘)Ru(η6-benzene)][PF6], Cp‘ = 1, has been determined.