Effects of reaction variables on enantioselectivity of modified Raney nickel catalyst

✍ Scribed by Pavel Kukula; Libor Červený

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 102 KB
• Volume: 185
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/s1381-1169(02)00024-9

✦ Synopsis

The effects of reaction variables (temperature, pressure, solvent type, substrate to catalyst ratio and substrate concentration) on enantioselectivity of methyl acetoacetate hydrogenation were studied. Raney nickel modified with (2R,3R)-(+)-tartaric acid was used as a catalyst. The reactions were carried out in a liquid phase, under atmospheric and increased hydrogen pressure. It was found that the reaction variables have a significant effect on the resulting enantioselectivity. A decrease of enantioselectivity either occurred at low substrate concentration in the reaction mixture or related to a catalyst. Changes of enantioselectivity were monitored during the reaction. The highest values of enantioselectivity were achieved under high hydrogen pressures (10 MPa), at a temperature of 60 • C and with tetrahydrofuran as the solvent.