Digitala Vetenskapliga Arkivet

Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Deracemization of Functionalized Alcohols via Combined Ruthenium and Enzyme Catalysis
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
Ansvarlig organisasjon
2006 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

The major part of this thesis describes the synthesis of enantiopure alcohols and diols by combining ruthenium-catalyzed racemization or epimerization and lipase-catalyzed asymmetric transformations. A minor part of this thesis is focused on ruthenium-catalyzed redox reactions for transfer hydrogenation of 1,3-cycloalkanediketones.

Kinetic resolution of racemic γ-hydroxy acid derivatives was performed via Pseudomonas cepacia lipase (PS-C)-catalyzed transesterification. γ-Hydroxy esters and γ-hydroxy amides were studied showing in higher selec-tivity and yields for the γ-hydroxy amides. The enzyme PS-C tolerates both variation in the chain length and different functionalities giving good to high enantioselectivity. Combining enzymatic kinetic resolution with a ruthenium-catalyzed racemization led to a dynamic kinetic resolution (DKR). The use of 2,4-dimethyl-3-pentanol as a hydrogen source to suppress ketone formation in the dynamic kinetic resolution increased the yields of the acetate product. The synthetic utility of this procedure was illustrated by the practical synthesis of the γ-lactone (R)-5-methyltetrahydrofuran-2-one.

A distereoselective transformation of cis/trans-1,3-cyclohexandiol using Candida antarctica lipase B (CALB)-catalyzed transesterification was of interest. Desymmetrization of cis-1,3-cyclohexanediol to the (R-monoacetate was successfully accomplished. Enantiopure (R,R)-diacetate was obtained from the (R)-monoacetate in a DYKAT process at room tem-perature. Metal- and enzyme-catalyzed transformation of cis/trans-1,3-cyclohexanediol using PS-C, gives a high diastereoselectivity for cis-diacetate. The (S)-mono-acetate was obtained from cis-diacetate by CALB-catalyzed hydrolysis. In addition, it was shown, by the use of deuterium-labeling that intramolecular acyl migration does not occur in the transformation of cis-monoacetate to the cis-diacetate.

Ruthenium-catalyzed transfer hydrogenation of 1,3-cyclohexanedione under microwave heating was developed as an efficient and fast method for the preparation of 1,3-cycloalkandiols.

sted, utgiver, år, opplag, sider
Stockholm: Institutionen för organisk kemi , 2006. , s. 51
HSV kategori
Identifikatorer
URN: urn:nbn:se:su:diva-789ISBN: 91-7155-200-6 (tryckt)OAI: oai:DiVA.org:su-789DiVA, id: diva2:199234
Disputas
2006-01-26, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 12 A, Stockholm, 13:00
Opponent
Veileder
Tilgjengelig fra: 2006-01-04 Laget: 2006-01-04 Sist oppdatert: 2012-06-26bibliografisk kontrollert
Delarbeid
1. Dynamic Kinetic Resolution of γ-Hydroxy acid Derivatives
Åpne denne publikasjonen i ny fane eller vindu >>Dynamic Kinetic Resolution of γ-Hydroxy acid Derivatives
2002 Inngår i: Tetrahedron Letters, ISSN 0040-4039, Vol. 43, nr 16, s. 2983-2986Artikkel i tidsskrift (Fagfellevurdert) Published
Identifikatorer
urn:nbn:se:su:diva-25246 (URN)
Merknad
Part of urn:nbn:se:su:diva-789Tilgjengelig fra: 2006-01-04 Laget: 2006-01-04bibliografisk kontrollert
2. Kinetic Resolution and Chemoenzymatic Dynamic Kinetic Resolution of Functionalized γ-Hydroxy Amides
Åpne denne publikasjonen i ny fane eller vindu >>Kinetic Resolution and Chemoenzymatic Dynamic Kinetic Resolution of Functionalized γ-Hydroxy Amides
2005 (engelsk)Inngår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 70, nr 7, s. 2582-2587Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

An efficient kinetic resolution of racemic gamma-hydroxy amides 1 was performed via Pseudomas cepacia lipase (PS-C)-catalyzed transesterification. The enzyme PS-C tolerates both variation in the chain length and different functionalities giving good to high enantioselectivity (E values of up to > 250). The combination of enzymatic kinetic resolution with a ruthenium-catalyzed racemization led to a dynamic kinetic resolution. The use of 2,4-dimethyl-3-pentanol as a hydrogen source to suppress ketone formation in the dynamic kinetic resolution yields the corresponding acetates in good yield and good to high enantioselectivity (ee's up to 98%). The synthetic utility of this procedure was illustrated by the practical synthesis of the versatile intermediate gamma-lactone (R)-5-methyltetrahydrofuran-2-one.

HSV kategori
Identifikatorer
urn:nbn:se:su:diva-25584 (URN)10.1021/jo0478252 (DOI)000227928200020 ()
Tilgjengelig fra: 2008-11-20 Laget: 2008-11-04 Sist oppdatert: 2022-02-25bibliografisk kontrollert
3. Enzymatic Resolution, Desymmetrization and Dynamic Kinetic Asym-metric Transformation of 1,3-Cycloalkanediols
Åpne denne publikasjonen i ny fane eller vindu >>Enzymatic Resolution, Desymmetrization and Dynamic Kinetic Asym-metric Transformation of 1,3-Cycloalkanediols
2006 (engelsk)Inngår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 71, nr 17, s. 6309-6316Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

An efficient desymmetrization of cis-1,3-cyclohexanediol to (1S,3R)-3-(acetoxy)-1-cyclohexanol ((R,S)-2a) was performed via Candida antarctica lipase B (CALB)-catalyzed transesterification, in high yield (up to 93%) and excellent enantioselectivity (ee's up to >99.5%). (R,R)-Diacetate ((R,R)-3a) was obtained in a DYKAT process at room temperature from (1S,3R)-3-acetoxy-1-cyclohexanol ((R,S)-2a), in a high trans/cis ratio (91:9) and in excellent enantioselectivity of >99%. Metal- and enzyme-catalyzed dynamic transformation of cis/trans-1,3-cyclohexanediol using PS-C gave a high diastereoselectivity for cis-diacetate (cis/trans = 97:3). The (1R,3S)-3-acetoxy-1-cyclohexanol (ent-(R,S)-2a) was obtained from cis-diacetate by CALB-catalyzed hydrolysis in an excellent yield (97%) and selectivity (>99% ee). By deuterium labeling it was shown that intramolecular acyl migration does not occur in the transformation of cis-monoacetate to the cis-diacetate.

sted, utgiver, år, opplag, sider
American Chemical Society, 2006
HSV kategori
Identifikatorer
urn:nbn:se:su:diva-25248 (URN)10.1021/jo060002n (DOI)
Merknad
Part of urn:nbn:se:su:diva-789Tilgjengelig fra: 2006-01-04 Laget: 2006-01-04 Sist oppdatert: 2022-02-25bibliografisk kontrollert
4. Highly Efficient Ru-catalyzed Transfer Hydrogenation/Hydrogenation Procedure for 1,3-Cycloalkandiols using Controlled Microwave Heating
Åpne denne publikasjonen i ny fane eller vindu >>Highly Efficient Ru-catalyzed Transfer Hydrogenation/Hydrogenation Procedure for 1,3-Cycloalkandiols using Controlled Microwave Heating
Manuskript (Annet vitenskapelig)
Identifikatorer
urn:nbn:se:su:diva-25249 (URN)
Merknad
Part of urn:nbn:se:su:diva-789Tilgjengelig fra: 2006-01-04 Laget: 2006-01-04 Sist oppdatert: 2010-01-13bibliografisk kontrollert

Open Access i DiVA

fulltekst(713 kB)1739 nedlastinger
Filinformasjon
Fil FULLTEXT01.pdfFilstørrelse 713 kBChecksum MD5
52d460ee741748aec6385a546926dab766979274884fe92f783c363088ef3a5cb31f09ad
Type fulltextMimetype application/pdf

Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar
Totalt: 1739 nedlastinger
Antall nedlastinger er summen av alle nedlastinger av alle fulltekster. Det kan for eksempel være tidligere versjoner som er ikke lenger tilgjengelige

isbn
urn-nbn

Altmetric

isbn
urn-nbn
Totalt: 963 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf