Novel Photocatalytic Asymmetric Synthesis of Δ (or Λ)-[Co(acac)3] (Hacac = pentane-2,4-dione) from [Co(acac)2(H2O)2] and Hacac with Helical Ruthenium(II) Tris-bidentate Complexes

The photoinduced asymmetric synthesis of Δ (or Λ)-[Co(acac)3] from [Co(acac)2(H2O)2] and Hacac was achieved by using helical Ruthenium(II) complexes of [Ru(Menbpy)3]2+ (Menbpy = 4,4′-di((1R,2S,5R)-(−)-menthoxycarbonyl)-2,2′-bipyridine), and [Ru(R(or S)-PhEtbpy)3]2+ (R(or S)-PhEtbpy = 4,4′-di((R)-(+)(or (S)-(−))-1-phenylethylamino-carbonyl)-2,2′-bipyridine) with the maximum 10.0% e.e. for the Λ-[Co(acac)3] formation by [Ru(Menbpy)3]2+ in 50–70% v/v EtOH/H2O at 25 °C.