Enantioface-Selective Coordination of Prochiral 1,3-Dienes to Planar-Chiral Cyclopentadienyl-Ruthenium Complexes

The treatment of planar-chiral (η5:η1-cyclopentadienylphosphine)bis(acetonitrile)ruthenium
complexes 1 with prochiral dienes led to the ligand-exchange reaction that gave (η5:η1-cyclopentadienylphosphine)(η4-diene)ruthenium complexes 4−6 and 8−11 with high enantioface selectivity (up to >99% de). The configuration of the (η4-diene)ruthenium complexes
was determined by crystallographic study of (η4-isoprene)ruthenium complex 6b-I and
spectral analyses, including NOE measurements. The selectivity of the reaction is under
thermodynamic control of the resulting η4-diene complexes and is affected by the substituents
on both the cyclopentadienyl ligand and the diene.