Neuere nichtsteroidartige entzündungshemmende Wirkstoffe (Antiphlogistica)

Shen, T. V.

doi:10.1002/ange.19720841104

Cited by 35 publications

(11 citation statements)

References 93 publications

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“…1) are important non-steroidal antiinflammatory drugs (Shen, 1972;Sonawane et al, 1992). They contain a chiral center and only one of the enantiomers is physiologically active (Caldwell et al, 1988).…”

Section: Introductionmentioning

confidence: 99%

Enantioselective hydrolysis of ketoprofen amide by Rhodococcus sp. C3II and Rhodococcus erythropolis MP 50

Layh

Knackmuss

1995

Biotechnol Lett

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The resolution of racemic ketoprofen amide by whole cells of Rhodococcus erythropolis MP 50 and Rhodococcus sp. C3II was studied. With both strains racemic ketoprofen amide was converted to S-ketoprofen with an enantiomeric excess > 97 % at a conversion rate up to 40 % of the theoretical value. The specific activity of strain MP 50 for ketoprofen amide was about 0.12 gmol min -1 and mg of dry weight and the substrate was converted for several hours at a constant rate.

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Section: Introductionmentioning

confidence: 99%

Enantioselective hydrolysis of ketoprofen amide by Rhodococcus sp. C3II and Rhodococcus erythropolis MP 50

Layh

Knackmuss

1995

Biotechnol Lett

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“…2-Arylpropionic acids such as ibuprofen and naproxen are important non-steroidal antiinflammatory drugs (Shen, 1972). They contain a chiral center and in vitro studies on inhibition of prostaglandin synthesis show that their activity resides almost exclusively in the S( + )-isomers * Correstxmding author.…”

Section: Introductionmentioning

confidence: 99%

Enantioselective hydrolysis of racemic naproxen nitrile and naproxen amide to S-naproxen by new bacterial isolates

Layh

Stolz

Böhme

et al. 1994

Journal of Biotechnology

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Bacteria were enriched from soil samples with succinate as a carbon source and racemic naproxen nitrile [2-(6-methoxy-2-naphthyl)propionitrile] as sole source of nitrogen. Since naproxen nitrile was only poorly soluble in water media amended with different water-immiscible organic phases were used for the enrichments. With pristane (2,6,10,14-tetramethylpentadecane) as the organic phase two bacterial strains were isolated (strain C3II and strain MP50) which were identified as rhodococci. Cells of both strains converted naproxen nitrile via naproxen amide to naproxen. From racemic naproxen nitrile Rhodococcus sp. C3II formed S-naproxen amide and subsequently S-naproxen. Racemic naproxen amide was hydrolysed to S-naproxen. Rhodococcus sp. MP50 converted racemic naproxen nitrile predominantly to R-naproxen amide and racemic naproxen amide to S-naproxen. With both strains racemic naproxen amide was converted to S-naproxen with an enantiomeric excess > 99% at a conversion rate up to 80% of the theoretical value. In strain C3II the enzymes which hydrolysed naproxen nitrile and naproxen amide were present only at a low constitutive level. In contrast, in Rhodococcus sp. MP50 these activities were induced when grown in the presence of various nitriles.

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“…The structure of complex (S a )-5 a was proved by an X-ray diffraction analysis of a single crystal. [5] According to the crystal structure, (S a )-3 a acts as a chelating P, N ligand and creates a rigid chiral pocket around the iridium center.The asymmetric hydrogenation of a-substituted acrylic acids 6 (for structures see Table 2) is of highly practical value because the products, optically pure a-substituted propionic acids, include important biologically active compounds. For example, ibuprofen (7 a) and naproxen (7 f), [6] two wellknown non-steroid anti-inflammatory drugs, can be readily prepared by asymmetric hydrogenation of the corresponding a-aryl acrylic acids.…”

mentioning

confidence: 99%

Enantioselective Hydrogenation of α‐Substituted Acrylic Acids Catalyzed by Iridium Complexes with Chiral Spiro Aminophosphine Ligands

et al. 2012

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The transition-metal-catalyzed asymmetric hydrogenation reactions attract long-lasting interest from both academic research and industrial production. [1] The development of chiral ligands is the essential impetus for the asymmetric hydrogenation reactions. During the past decades, chiral P, N ligands having both phosphorus and nitrogen atoms as the coordinating groups become popular in the hydrogenation reactions. [2] Generally, molecules with sp 2 nitrogen atoms, such as oxazoline and pyridine, are required for achieving good results for the chiral P, N ligands. Although several phosphine amine ligands containing primary amine moieties have been successfully applied in the highly enantioselective hydrogenation of ketones, [3] to our knowledge, such ligands have not been applied successfully in the asymmetric hydrogenation of olefins. Herein we report the preparation of novel chiral spiro aminophosphine ligands bearing a primary amine moiety 3 (Scheme 1) and their applications in the hydrogenation of a,b-unsaturated carboxylic acids. The iridium complexes 5 derived from the chiral spiro aminophosphine ligands showed unprecedentedly high activity (turnover numbers (TONs) up to 10 000; turnover frequencies (TOFs) up to 6000 h À1 ) and enantioselectivity (94-99 % ee). The primary amine moiety in the catalysts 5 is the key for obtaining high activity and enantioselectivity.Chiral spiro aminophosphine ligands 3 and 4 were easily prepared starting from optically pure 1 (Scheme 1). [4] Palladium-catalyzed cyanation of 1 (step a) followed by LiAlH 4 reduction (step b) afforded ligands 3 in good yield. Ligands 4, which have an N-methyl group, were prepared from 3 through condensation with ethyl chloroformate and LiAlH 4 reduction in one pot (step c). The iridium complexes 5 were prepared by refluxing a mixture of [{Ir(cod)Cl} 2 ], 3 or 4, and NaBAr F in dichloromethane for two hours (step d). Complexes 5 were stable enough to be purified by silica gel column chromatography and stored in air without degradation for a few months. The structure of complex (S a )-5 a was proved by an X-ray diffraction analysis of a single crystal. [5] According to the crystal structure, (S a )-3 a acts as a chelating P, N ligand and creates a rigid chiral pocket around the iridium center.The asymmetric hydrogenation of a-substituted acrylic acids 6 (for structures see Table 2) is of highly practical value because the products, optically pure a-substituted propionic acids, include important biologically active compounds. For example, ibuprofen (7 a) and naproxen (7 f), [6] two wellknown non-steroid anti-inflammatory drugs, can be readily prepared by asymmetric hydrogenation of the corresponding a-aryl acrylic acids. Although chiral ruthenium catalysts usually give high enantioselectivity in the asymmetric hydrogenation of a-substituted acrylic acids, most of these catalysts require high hydrogen pressure (e.g., 100 atm) to achieve complete conversion and high enantioselectivity. [7] The high pressure markedly limits the practical applicatio...

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Neuere nichtsteroidartige entzündungshemmende Wirkstoffe (Antiphlogistica)

Cited by 35 publications

References 93 publications

Enantioselective hydrolysis of ketoprofen amide by Rhodococcus sp. C3II and Rhodococcus erythropolis MP 50

Enantioselective hydrolysis of ketoprofen amide by Rhodococcus sp. C3II and Rhodococcus erythropolis MP 50

Enantioselective hydrolysis of racemic naproxen nitrile and naproxen amide to S-naproxen by new bacterial isolates

Enantioselective Hydrogenation of α‐Substituted Acrylic Acids Catalyzed by Iridium Complexes with Chiral Spiro Aminophosphine Ligands

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