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Enantio-differentiating hydrogenation of methyl acetoacetate over modified nickel catalysts: effects of nickel dispersion on the enantio-selectivity of catalysts

Enantio-differentiating hydrogenation of methyl acetoacetate over modified nickel catalysts:... 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. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Research on Chemical Intermediates Springer Journals

Enantio-differentiating hydrogenation of methyl acetoacetate over modified nickel catalysts: effects of nickel dispersion on the enantio-selectivity of catalysts

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References (1)

Publisher
Springer Journals
Copyright
Copyright © 2004 by VSP
Subject
Chemistry; Inorganic Chemistry; Physical Chemistry; Catalysis
ISSN
0922-6168
eISSN
1568-5675
DOI
10.1163/1568567042420730
Publisher site
See Article on Publisher Site

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.

Journal

Research on Chemical Intermediates – Springer Journals

Published: Nov 1, 2004

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