New synthetic routes toward enantiopure nitrogen donor ligands

The preparation of new polypyridylic chiral ligands having either [C.sub.3] or lower symmetry via a de novo construction of the pyridine nucleus by means of Krohnke methodology is presented. The preliminary catalytic results performed with the Ru complex (-)-21 show moderate enantioselectivities in styrene epoxidation with PhI[(AcO).sub.2].