Model for Enantioselective Hydrogenation of α-Ketoesters over Chirally Modified Platinum Revisited: Influence of α-Ketoester Conformation

Buergi, Thomas; Baiker, A.

doi:10.1006/jcat.2000.2958

Scientific article

English

Model for Enantioselective Hydrogenation of α-Ketoesters over Chirally Modified Platinum Revisited: Influence of α-Ketoester Conformation

Contributors

Buergi, Thomas; Baiker, A.

Published in

Journal of catalysis, vol. 194, no. 2, p. 445-451

Publication date

2000

Abstract

Interaction complexes between cinchonidine modifier and methyl pyruvate reactant proposed for the enantioselective hydrogenation over platinum catalysts have been calculated using ab initio methods. For s-trans-methyl pyruvate it was found that the complex yielding (R)-methyl lactate upon hydrogenation was more stable than the corresponding pro-(S) complex. The calculated energy difference of 1.8 kcal/mol corresponds to an enantiomeric excess of 92%, in good agreement with experiment. For the analogous complexes of s-cis-methyl pyruvate the energy difference is only 0.2 kcal/mol in favour of pro-(R), corresponding to 17% enantiomeric excess. Due to the larger dipole moment of the s-cis conformer of methyl pyruvate its hydrogen-bonded complexes with cinchonidine are considerably more stable than the corresponding s-trans complexes. However, the predicted low enantiomeric excess for the s-cis conformer is in contrast with experiment. Possible reasons for this behaviour are discussed.

UNIGE affiliation entities

Not a UNIGE publication

Citation (ISO format)

BUERGI, Thomas, BAIKER, A. Model for Enantioselective Hydrogenation of α-Ketoesters over Chirally Modified Platinum Revisited: Influence of α-Ketoester Conformation. In: Journal of catalysis, 2000, vol. 194, n° 2, p. 445–451. doi: 10.1006/jcat.2000.2958

Article (Published version)

Identifiers

PID : unige:14809
DOI : 10.1006/jcat.2000.2958

Additional URL for this publication

http://linkinghub.elsevier.com/retrieve/pii/S0021951700929580

Journal ISSN

0021-9517

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22/03/2011 09:54:00

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22/03/2011 09:54:00

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14/03/2023 16:14:29

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14/03/2023 16:14:29

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29/10/2024 17:59:14

Model for Enantioselective Hydrogenation of α-Ketoesters over Chirally Modified Platinum Revisited: Influence of α-Ketoester Conformation

Contributors

Published in

Publication date

Abstract

UNIGE affiliation entities

Citation (ISO format)

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Identifiers

Additional URL for this publication

Journal ISSN

Technical informations

Creation

First validation

Update

Status update

Last indexation