Kinetics and mechanism of catalysis of the asymmetric hydrogenation of .alpha.,.beta.-unsaturated carboxylic acids by bis(carboxylato) {2,2'-bis(diphenylphosphino)-1,1'-binaphthyl}ruthenium(II), [RuII(BINAP) (O2CR)2]

Ashby, Michael T.; Halpern, Jack

doi:10.1021/ja00002a029

Cited by 161 publications

(95 citation statements)

References 4 publications

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“…As a result, the reaction orders of all organic liquid reactants (MAA, K and HK) were found to be 1. Similar data have been obtained in the literature for the asymmetric hydrogenation of unsaturated carboxylic acids with Ru-BINAP systems (reaction order = 1) [16] and for the asymmetric hydrogenation of tiglic acid with Ru-BINAP systems (reaction order = 0.881-0.929). [17] In another set of experiments the reaction order with respect to hydrogen was derived experimentally by varying the hydrogen pressure from 5 to 20 bar.…”

Section: Estimation Of Kinetic Parameterssupporting

confidence: 87%

Kinetic Study of the Asymmetric Hydrogenation of Methyl Acetoacetate in the Presence of a Ruthenium Binaphthophosphepine Complex

et al. 2009

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Abstract:The asymmetric hydrogenation of methyl acetoacetate (MAA) in methanol using dibromobis{(S)-4-phenyl-4,5-dihydro-3H-dinaphtho[2,1-c: 1',2'-e]phosphepine}-ruthenium was studied in detail. For the determination of the reaction network, data from kinetic experiments were compared to different possible reaction networks using the kinetic software Presto Kinetics. The simulation was optimised to describe the reaction accurately with a minimal set of process parameters and reaction equations. For the best model the reaction orders, collision factors and activation energy of all reaction steps were determined. Additionally, the influence of reaction temperature and hydrogen pressure on the enantiomeric excess (ee) of the reaction was studied. It was found that high reaction temperatures and high hydrogen pressures result in increasing enantioselectivities.

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Section: Estimation Of Kinetic Parameterssupporting

confidence: 87%

Kinetic Study of the Asymmetric Hydrogenation of Methyl Acetoacetate in the Presence of a Ruthenium Binaphthophosphepine Complex

et al. 2009

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“…As speculated by Halpern et al [34] for a,b-unsaturated acids, coordination occurs first through the carboxylate functional group. Next, either keto and/or enol hydrogenation can occur.…”

Section: Mechanism Of Hydrogenationmentioning

confidence: 83%

“…Scheme 6 shows several possible hydrogenation pathways for the production of cis and trans diastereo-mers, based on the following findings from previous studies: (i) binding of the carboxylate moiety to the Ru(II) catalyst is possible and favoured, [27,32] and (ii) the hydrogenation of b-keto esters [33] and a,b-unsaturated acids [34] proceeds through a monohydride ruthenium mechanism. As speculated by Halpern et al [34] for a,b-unsaturated acids, coordination occurs first through the carboxylate functional group.…”

Section: Mechanism Of Hydrogenationmentioning

confidence: 99%

β‐Hydroxycarboxylic Acids from Simple Ketones by Carboxylation and Asymmetric Hydrogenation

2008

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We present a new asymmetric synthesis of b-hydroxycarboxylic acids from ketones, performed by carboxylation using CO 2 followed by asymmetric hydrogenation. First, the carboxylation of ketones gives b-ketocarboxylic acids. The effects of temperature, reaction time, and amount of 1,.0]undec-7-ene (DBU) promoter on the carboxylation were investigated. The DBU can be recycled. For the second step, the asymmetric hydrogenation of these b-ketocarboxylic acids, we determined the effect of solvent choice, H 2 pressure, and substrate substitution. Hydrogenation yield and enantioselectivity are solvent-dependent, and the mechanism could proceed through hydrogenation of either the enol or the keto forms of the bound substrate. This synthesis is industrially advantageous due to the limited number of reactants required, their low-cost, and the potential for recycling unused materials.

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“…3. The hydrogenation proceeds by a Ru II monohydride species A (27,28), which is expected to react reversibly with the substrate to afford the adduct B (28). Further intramolecular hydride transfer provides the ruthenium alkoxide C (29).…”

Section: Steric Profiling Of Synphos and Difluorphosmentioning

confidence: 99%

Chiral biphenyl diphosphines for asymmetric catalysis: Stereoelectronic design and industrial perspectives

Jeulin

Paule

Ratovelomanana‐Vidal

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

124

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Kinetics and mechanism of catalysis of the asymmetric hydrogenation of .alpha.,.beta.-unsaturated carboxylic acids by bis(carboxylato) {2,2'-bis(diphenylphosphino)-1,1'-binaphthyl}ruthenium(II), [RuII(BINAP) (O2CR)2]

Cited by 161 publications

References 4 publications

Kinetic Study of the Asymmetric Hydrogenation of Methyl Acetoacetate in the Presence of a Ruthenium Binaphthophosphepine Complex

Kinetic Study of the Asymmetric Hydrogenation of Methyl Acetoacetate in the Presence of a Ruthenium Binaphthophosphepine Complex

β‐Hydroxycarboxylic Acids from Simple Ketones by Carboxylation and Asymmetric Hydrogenation

Chiral biphenyl diphosphines for asymmetric catalysis: Stereoelectronic design and industrial perspectives

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