Asymmetric Hydrogenation Catalyzed by Bis(disubstituted glyoximato)cobalt(II)(L)-Chiral Cocatalyst System. Effect of Structural Variation of Ligands and Hydrogen Pressure

Abstract
The reaction rate was extremely enhanced by increasing the basicity of the axial ligand of [Co(dmgH)2(L)] and by increasing the hydrogen pressure without decreasing the enantioselectivity. Substituting one and two methyl groups of the dimethylglyoxime ligand in [Co(dmgH)2(L)] with a phenyl group enhanced and retarded the reaction rate, respectively. The chirality at the cobalt did not affect the enantioselectivity.