Enantio-differentiating hydrogenation of methyl acetoacetate over modified nickel catalysts: effects of nickel dispersion on the enantio-selectivity of catalysts
- Title
- Enantio-differentiating hydrogenation of methyl acetoacetate over modified nickel catalysts: effects of nickel dispersion on the enantio-selectivity of catalysts
- Authors
- Jo, DH; Lee, JS; Lee, KH; 이경희
- Date Issued
- 2004-01
- Publisher
- VSP BV
- Abstract
- Enantio-differentiating hydrogenation of methyl acetoacetate was performed over the supported nickel catalysts modified by the solution of (R,R)-tartaric acid or (S)-malic acid and NaBr. The reduction temperature of supported nickel was the most important factor determining the enantio-selectivity of catalysts. The reduction temperature changed the nickel dispersion, by which the quantity and coverage of modifier adsorption were varied. The enantio-selectivity of modifiers both (R,R)-tartaric acid and (S)-malic acid were compared at various reduction temperatures. (R,R)tartaric acid with two hydroxyl groups in a molecule showed an optimum coverage on the nickel surface that gave the maximum ee value. The maximum ee value was 72% at the reduction temperature of 973 K. In contrast, (S)-malic acid with one hydroxyl group in a molecule showed a monotonous decrease in ee and decreasing amounts of adsorbed modifier with increasing reduction temperatures.
- Keywords
- enantio-differentiating hydrogenation; tartaric acid; malic acid; methyl acetoacetate; MODIFIED RANEY-NICKEL; C=O DOUBLE-BOND; SILICA-SUPPORTED NICKEL; IN-SITU MODIFICATION; TARTARIC ACID; ASYMMETRIC HYDROGENATION; DEPOSITION-PRECIPITATION; (R,R)-TARTARIC ACID; PROCHIRAL KETONES; NI/SIO2 CATALYST
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/24851
- ISSN
- 0922-6168
- Article Type
- Article
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- There are no files associated with this item.
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