- Developing a Biocascade Process: Concurrent Ketone Reduction-Nitrile Hydrolysis of 2-Oxocycloalkanecarbonitriles
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A stereoselective bioreduction of 2-oxocycloalkanecarbonitriles was concurrently coupled to a whole cell-catalyzed nitrile hydrolysis in one-pot. The first step, mediated by ketoreductases, involved a dynamic reductive kinetic resolution, which led to 2-hydroxycycloalkanenitriles in very high enantio- and diastereomeric ratios. Then, the simultaneous exposure to nitrile hydratase and amidase from whole cells of Rhodococcus rhodochrous provided the corresponding 2-hydroxycycloalkanecarboxylic acids with excellent overall yield and optical purity for the all-enzymatic cascade.
- Liardo, Elisa,Ríos-Lombardía, Nicolás,Morís, Francisco,González-Sabín, Javier,Rebolledo, Francisca
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supporting information
p. 3366 - 3369
(2016/07/26)
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- PEG600-carboxylates as efficient reusable reaction media and acylating agents for the resolution of sec-alcohols
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Herein is presented a simple, attractive, and reusable methodology for one-pot resolution/separation of free sec-alcohols with enantiomeric excess (ee) values over 90% by the combination of sustainable acylating agents/solvents (polyethylene glycol derivatives) and an easily available and common biocatalyst (Candida antarctica lipase B, or CAL B) under irreversible conditions, along with a separation process by extraction or distillation. A scale-up reaction was carried out with the Fluoxetine precursor with ee values close to 90% for the R enantiomer.
- Monteiro, Carlos M.,Lourenco, Nuno M. T.,Ferreira, Frederico C.,Afonso, Carlos A. M.
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- Enzymatic resolution of trans-2-hydroxycyclohexanecarbonitrile in supercritical carbon dioxide
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A novel, highly enantioselective (E ? 100) and environmentally benign method is presented for the kinetic resolution of trans-2- hydroxycyclohexanecarbonitrile in supercritical carbon dioxide. Using Candida antarctica Lipase B as a biocatalyst and vinyl a
- Utczás, Margita,Székely, Edit,Forró, Enik,Szllsy, áron,Fül?p, Ferenc,Simándi, Béla
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scheme or table
p. 3916 - 3918
(2011/08/09)
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- Ionic acylating agents for the enzymatic resolution of sec-alcohols in ionic liquids
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Potential acylating agents containing pendant ionic groups have been screened for the enzymatic kinetic resolution of rac-secondary alcohols in ionic liquids with CAL-B as biocatalyst. This study has allowed the identification of the 1-methyl-3-alkylimidazolium cation attached to a carboxylate group through a C10-alkyl chain as an efficient acylating agent for this transformation. This strategy was applied to the resolution of 2-hydroxycyclohexanecarbonitrile in which the 1R,2S enantiomer was isolated in 35 % ee (73 % yield) and the 1S,2R enantiomer in 97 % ee (23 % yield). Potential acylating agents containing pendant ionic groups have been screened for the enzymatic kinetic resolution of rac-secondary alcohols in ionic liquids with CAL-B as biocatalyst. This study has allowed theidentification of the 1-methyl-3-alkylimidazolium cation attached to a carboxylate group through a C10-alkyl chain as an efficient acylating agent for this transformation. Copyright
- Lourenco, Nuno M. T.,Monteiro, Carlos M.,Afonso, Carlos A. M.
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experimental part
p. 6938 - 6943
(2011/02/24)
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- A chemoenzymatic synthesis of an androgen receptor antagonist
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A new scalable enzymatic resolution approach to both enantiomers of trans-2-hydroxycyclohexanecarbonitrile (9 and 11) was developed. Treatment of the racemic mixture (4) with succinic anhydride in the presence of Novozym 435 led to selective acylation of one enantiomer to the corresponding hemisuccinate, which was separated from the unreacted enantiomer by a simple basic extraction. This procedure produced the desired enantiomer in high ee, while obviating the need for chromatography or expensive catalysts and ligands. The application of this protocol to the large-scale synthesis of an androgen receptor antagonist (1) is described.
- Vaidyanathan, Rajappa,Hesmondhalgh, Lynsey,Hu, Shanghui
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p. 903 - 906
(2012/12/30)
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- Asymmetric ring opening of meso epoxides with TMSCN catalyzed by (pybox)lanthanide complexes.
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The asymmetric ring opening of meso epoxides with TMSCN is catalyzed by (pybox)YbCl3 complexes, yielding the beta-trimethylsilyloxy nitrile ring-opened products with good enantioselectivities (83-92% ee). The reaction exhibits a second-order kinetic depen
- Schaus,Jacobsen
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p. 1001 - 1004
(2007/10/03)
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- Preparation of the stereoisomers of 2-cyanocycloalkanols by lipase-catalysed acylation
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Enantiopure (1R,2R)-, (1S,2S)-, (1S,2R)- and (1R,2S)-2-cyanocyclopentanol and -cyclohexanol isomers were prepared through the Pseudomonas cepacia lipase-catalysed acetylation of the racemic cis and trans compounds with vinyl acetate in diisopropyl ether.
- Forro, Eniko,Lundell, Katri,Fueloep, Ferenc,Kanerva, Liisa T.
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p. 3095 - 3099
(2007/10/03)
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