RUTHENIUM(II) ARENES COMPLEXES OF OPTICALLY-ACTIVE P.N DONOR LIGANDS - SYNTHESIS AND STUDY OF THEIR CATALYTIC ACTIVITY FOR THE HYDROGENATION OF ACETOPHENONE

Seven complexes of the type [(p-cymene)Ru(PN)Cl] [BPh4], in which PN* represents new optically active ligand associating phosphorous to nit rogen as donating centres, have been synthesised. These complexes have been fully characterised by spectroscopic means and, in addition, the solid state structure of two of them has been determined by X-ray cry stallography. In solution, variable temperature NMR studies give evide nce of a rotation around the Ru-arene axis with a low energy barrier. The catalytic performances of these complexes have been evaluated for the hydrogenation of acetophenone, and have been found to be low, both in term of activity and enantioselectivity.