Highly durable enantio-differentiating nickel catalyst for repeated use for the hydrogenation of methyl acetoacetate

The enantio-differentiating hydrogenation of methyl acetoacetate was repeated 30 times over a fine Ni powder catalyst while modifiers (optically active tartaric acid and NaBr) were directly added to the reaction media only in the first run. Over 80% optical yields were attained for the repeated runs. The addition of sodium 2-ethylhexanoate increased the optical yields in the subsequent runs. The very simple and highly durable enantio-differentiating nickel catalyst for repeated use was developed by an in situ modification.