The modification of some rare earth metal cations to polymer-stabilized Pt
colloidal clusters leads to significant increase in both the ee and the act
ivity in the homogeneous enantioselective hydrogenation of methyl pyruvate
to (R)-(+)-methyl lactate. Compared to ee (72.5%) in the absence of rare ea
rth cations, the highest ee (88.0%) in ethanol solvent is obtained by addin
g a suitable amount of Yb3+ into the Pt colloidal cluster catalyst. The mod
ification effect of rare earth cations is also effective in other alcohol a
nd water solvents.