Chiral Auxiliaries as Docking/Protecting Groups in Biohydroxylation: The Hydroxylation of Enantiopure Spirooxazolidines Derived from Cyclopentanone UsingBeauveria bassiana ATCC 7159

Raadt, Anna De; Fetz, Barbara; Griengl, Herfried; Klingler, Markus; Kopper, I.; Krenn, Birgit; Münzer, Dieter; Ott, René Georg; Plachota, Peter; Weber, Hans Jörg; Braunegg, G.; Mosler, Winfried; Saf, Robert

doi:10.1002/1099-0690(200012)2000:23<3835::aid-ejoc3835>3.0.co;2-e

Cited by 14 publications

(9 citation statements)

References 36 publications

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“…Subsequent reaction with cyclopentanone afforded the desired, enantiopure substrates 7 and 8 , respectively (Scheme ). In contrast to previous observations, these compounds were obtained in only modest yields under standard, unoptimized conditions5,8 (22 % and 17 %, respectively).…”

Section: Resultscontrasting

confidence: 94%

“…Satisfyingly, although ketone 4 was found to be ( R )‐configured (19 % ee ), ketone 11 was found to be ( S )‐configured and with a high ee (89 %). It should be mentioned at this point that, based on published experiments5 with product 3 , this ee value should increase after simple recrystallisation of compound 9 . This result nicely complements those obtained from the ( R )‐methyl d/p used in previous studies (Scheme ) where product 3 could be obtained in 90 % de in a single biohydroxylation step.…”

Section: Resultsmentioning

confidence: 96%

“…Spirooxazolidine Derivative 8: Employing the standard procedure for preparing spirooxazolidine derivatives,5 compound 8 was prepared in 17 % yield as a pale‐yellow, crystalline solid. M.p.…”

Section: Methodsmentioning

confidence: 99%

“…Biohydroxylation Product 10: Employing published methods,5 treatment of compound 8 (759.6 mg) with Beauveria bassiana ATCC 7159 gave the title compound (160.6 mg), together with unreacted starting material (65.8 mg), as a white solid (22 % yield, taking into account unreacted starting material). M.p.…”

Section: Methodsmentioning

confidence: 99%

“…Chiral d/p groups have also been investigated5,6 and employed for the hydroxylation of ketones. In this manner, the stereoselective functionalisation of these compounds was achieved.…”

Section: Introductionmentioning

confidence: 99%

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Chiral Auxiliaries as Docking/Protecting Groups in Biohydroxylation:(S)‐Specific Hydroxylation of Enantiopure tert‐Butyl‐Substituted Spirooxazolidines Derived From Cyclopentanone

et al. 2005

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Section: Resultscontrasting

confidence: 94%

Section: Resultsmentioning

confidence: 96%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…Chiral d/p groups have also been investigated5,6 and employed for the hydroxylation of ketones. In this manner, the stereoselective functionalisation of these compounds was achieved.…”

Section: Introductionmentioning

confidence: 99%

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Chiral Auxiliaries as Docking/Protecting Groups in Biohydroxylation:(S)‐Specific Hydroxylation of Enantiopure tert‐Butyl‐Substituted Spirooxazolidines Derived From Cyclopentanone

et al. 2005

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Chiral Alcohols by Enzymatic Preparation

Borup

Daußmann²,

Collier³

2010

Encyclopedia of Industrial Biotechnology

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Biocatalytic processes are of increasing importance in the production of chiral alcohols which are important building blocks in the synthesis of chemical catalysts, liquid crystals, agrochemicals and pharmaceuticals. Methods for the synthesis of chiral alcohols can be subdivided into three general classes: traditional (such as classic racemic resolution, chromatography, chiral pool synthesis), asymmetric chemical, and biological (enzymes, whole microbial cells) methods. The last can also be applied to the more traditional methods. Enzymatic techniques are attracting a growing interest as green catalysts because of the different advantages they offer, as compared to other methods: high selectivity, high product purity, mild reaction conditions, competitive production costs, and excellent catalyst availability. In this contribution we give an overview of the biocatalytic approaches for the manufacture of chiral alcohols. To our knowledge there are currently about five major enzyme groups applied for the synthesis of chiral alcohols. The first one reduces carbonyl functional groups (ketones) to enantiopure secondary alcohols (dehydrogenases or reductases). The second group forms alcohols by introduction of molecular oxygen with concomitant one or two electron reduction (mono‐ and dioxygenases). The third group forms alcohols by addition of water to unsaturated carbon carbon double bonds (hydratases) whereas the fourth one forms alcohols by nucleophilic addition of small molecules such as HCN at carbonyl groups which usually also results in a new C–C bond formation (hydroxynitrile lyases and aldolases). The last major group of enzymes discussed herein belongs to the traditional methods mentioned above and resolves racemic chiral alcohols by reacting with only one enantiomer in a racemic mixture (hydrolases). In a selection of case studies we demonstrate the high level of importance that biocatalytic processes have already gained in the industrial manufacture of chiral alcohols. There are numerous processes available that have been or still are operated in multi‐tonne scale. By solving the drawback of cofactor requirements and regeneration for a range of enzymes, especially in the area of asymmetric reduction, the dehydrogenases and oxygenases are now commonly used for commercial processes and are in several cases superior to whole‐cell microbial processes. The highly competitive nature of enzymatic processes compared to whole‐cell (fermentation) and chemical approaches is demonstrated with the example of the manufacture of optically active ethyl ( R )‐3‐hydroxybutyrate.

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Substituent Position‐Controlled Stereoselectivity in Enzymatic Reduction of Diaryl‐ and Aryl(heteroaryl)methanones

Wang

et al. 2019

Adv Synth Catal

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We report here the discovery of a novel ketoreductase (KRED), named KmCR2, with a broad substrate spectrum on bioreduction of sterically bulky diaryl‐ and aryl(heteroaryl)methanones. The position of the substituent on aromatic rings (meta versus para or ortho) was revealed to control the stereospecificity of KmCR2. The stereoselective preparation of both enantiomers of diaryl‐ or aryl(heteroaryl)methanols using strategically engineered substrates with a traceless directing group (bromo group) showcased the potential application of this substrate‐controlled bioreduction reaction. The combined use of substrate engineering and protein engineering, was demonstrated to be a useful strategy in efficiently improving stereoselectivity or switching stereopreference of enzymatic processes.magnified image

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Chiral Auxiliaries as Docking/Protecting Groups in Biohydroxylation: The Hydroxylation of Enantiopure Spirooxazolidines Derived from Cyclopentanone UsingBeauveria bassiana ATCC 7159

Cited by 14 publications

References 36 publications

Chiral Auxiliaries as Docking/Protecting Groups in Biohydroxylation:(S)‐Specific Hydroxylation of Enantiopure tert‐Butyl‐Substituted Spirooxazolidines Derived From Cyclopentanone

Chiral Auxiliaries as Docking/Protecting Groups in Biohydroxylation:(S)‐Specific Hydroxylation of Enantiopure tert‐Butyl‐Substituted Spirooxazolidines Derived From Cyclopentanone

Chiral Alcohols by Enzymatic Preparation

Substituent Position‐Controlled Stereoselectivity in Enzymatic Reduction of Diaryl‐ and Aryl(heteroaryl)methanones

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