Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Transition Metal-Catalyzed Redox Reactions: A Journey from Homogeneous Ruthenium to Heterogeneous Palladium Catalysis
Stockholm University, Faculty of Science, Department of Organic Chemistry.
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The first part of the thesis covers the development and utilization of electronically modified (pentaarylcyclopentadienyl)Ru-complexes in the racemization of secondary alcohols. This study revealed that the electronic properties of the substrate were the main factors dictating whether β-hydride elimination or hydride re-addition becomes the rate-determining step of the racemization process. With this knowledge in hand, it proved to be possible to design more efficient racemization protocols by matching the electronic properties of catalyst and substrate.

The second part describes mechanistic work that aimed at elucidating the role of CO dissociation in the mechanism of secondary alcohol racemization catalyzed by a (pentaarylcyclopentadienyl)Ru-complex. From CO exchange studies, we demonstrated that CO dissociation occurred in the catalytically active tert-BuO-species as well as in the chloride precatalyst. Furthermore, an inhibition study showed that an increase of the partial pressure of CO had a negative influence on the racemization rate. Together, these two observations provide strong support for CO dissociation as a key step in the racemization of secondary alcohols.

The third part concerns the improved synthesis and characterization of a heterogeneous catalyst consisting of Pd nanoparticles immobilized on aminopropyl-functionalized siliceous mesocellular foam. The developed Pd nanocatalyst was found to be a highly efficient and recyclable catalyst for the aerobic oxidation of a wide range of primary and secondary alcohols to the corresponding aldehydes and ketones.

The fourth part deals with the successful application of the Pd nanocatalyst in chemically-induced H2O oxidation, when using either ceric ammonium nitrate or [Ru(bpy)3]3+ as the terminal oxidant. Remarkably, the Pd nanocatalyst proved to catalyze this reaction with high efficiency and the measured TOF was found to greatly exceed those of current state-of-the-art metal oxide catalysts.

The fifth and final part describes the co-immobilization of Pd nanoparticles and the enzyme Candida Antarctica Lipase B into the same cavities of mesocellular foam, to generate a “metalloenzyme-like” hybrid catalyst for the dynamic kinetic resolution of a primary amine. The close proximity of the two catalytic species led to an enhanced cooperativity between them and resulted in an overall more efficient tandem process. 

Place, publisher, year, edition, pages
Stockholm: Department of Organic Chemistry, Stockholm University , 2013. , 95 p.
National Category
Organic Chemistry
Research subject
Organic Chemistry
Identifiers
URN: urn:nbn:se:su:diva-96713ISBN: 978-91-7447-828-0 (print)OAI: oai:DiVA.org:su-96713DiVA: diva2:667257
Public defence
2014-01-24, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 16 B, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Epub ahead of print.

Available from: 2014-01-02 Created: 2013-11-26 Last updated: 2014-06-12Bibliographically approved
List of papers
1. Tuning of the Electronic Properties of a Cyclopentadienylruthenium Catalyst to Match Racemization of Electron-Rich and Electron-Deficient Alcohols
Open this publication in new window or tab >>Tuning of the Electronic Properties of a Cyclopentadienylruthenium Catalyst to Match Racemization of Electron-Rich and Electron-Deficient Alcohols
2011 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 17, no 40, 11216-11222 p.Article in journal (Refereed) Published
Abstract [en]

The synthesis of a new series of cyclopentadienylruthenium catalysts with varying electronic properties and their application in racemization of secondary alcohols are described. These racemizations involve two key steps: 1) β-hydride elimination (dehydrogenation) and 2) re-addition of the hydride to the intermediate ketone. The results obtained confirm our previous theory that the electronic properties of the substrate determine which of these two steps is rate determining. For an electron-deficient alcohol the rate-determining step is the β-hydride elimination (dehydrogenation), whereas for an electron-rich alcohol the re-addition of the hydride becomes the rate-determining step. By matching the electronic properties of the catalyst with the electronic properties of the alcohol, we have now shown that a dramatic increase in racemization rate can be obtained. For example, electron-deficient alcohol 15 racemized 30 times faster with electron-deficient catalyst 6 than with the unmodified standard catalyst 4. The application of these protocols will extend the scope of cyclopentadienylruthenium catalysts in racemization and dynamic kinetic resolution.

Place, publisher, year, edition, pages
Wiley-VCH Verlag GmbH 3690 & Co. KGaA, Weinheim, 2011
Keyword
alcohols, cyclopentadienyl ligands, dynamic kinetic resolution, racemization, rutheniumm
National Category
Organic Chemistry
Identifiers
urn:nbn:se:su:diva-64555 (URN)10.1002/chem.201100827 (DOI)000297013100021 ()
Available from: 2011-11-22 Created: 2011-11-22 Last updated: 2017-12-08Bibliographically approved
2. CO dissociation mechanism in racemization of alcohols by a cyclopentadienyl ruthenium dicarbonyl catalyst
Open this publication in new window or tab >>CO dissociation mechanism in racemization of alcohols by a cyclopentadienyl ruthenium dicarbonyl catalyst
2011 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 133, no 9, 2820-2823 p.Article in journal (Refereed) Published
Abstract [en]

13CO exchange studies of racemization catalyst (η5-Ph5C5)Ru(CO)2Cl and (η5-Ph5C5)Ru(CO)2(Ot-Bu) by 13C NMR spectroscopy are reported. CO exchange for the active catalyst form, (η5-Ph5C5)Ru(CO)2(Ot-Bu) is approximately 20 times faster than that for the precatalyst (η5-Ph5C5)Ru(CO)2Cl. An inhibition on the rate of racemization of (S)-1-phenylethanol was observed on addition of CO. These results support the hypothesis that CO dissociation is a key step in the racemization of sec-alcohols by (η5-Ph5C5)Ru(CO)2Cl, as also predicted by DFT calculations.

National Category
Organic Chemistry
Research subject
Organic Chemistry
Identifiers
urn:nbn:se:su:diva-59869 (URN)10.1021/ja1098066 (DOI)000289455200008 ()
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation
Available from: 2011-07-20 Created: 2011-07-20 Last updated: 2017-12-08Bibliographically approved
3. Highly dispersed palladium nanoparticles on mesocellular foam: an efficient and recyclable heterogeneous catalyst for alcohol oxidation
Open this publication in new window or tab >>Highly dispersed palladium nanoparticles on mesocellular foam: an efficient and recyclable heterogeneous catalyst for alcohol oxidation
Show others...
2012 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 18, no 39, 12202-12206 p.Article in journal (Refereed) Published
Keyword
green chemistry, heterogeneous catalysis, O–O activation, oxidation, palladium nanoparticles
National Category
Organic Chemistry
Identifiers
urn:nbn:se:su:diva-81837 (URN)10.1002/chem.201202157 (DOI)000308879000005 ()
Funder
Knut and Alice Wallenberg Foundation
Note

AuthorCount:9;

Available from: 2012-11-01 Created: 2012-11-01 Last updated: 2017-12-07Bibliographically approved
4. Well-Defined Palladium Nanoparticles Supported on Amino-Functionalized Siliceous Mesocellular Foam: An Efficient Heterogeneous Catalyst for Chemically-Induced H2O Oxidation
Open this publication in new window or tab >>Well-Defined Palladium Nanoparticles Supported on Amino-Functionalized Siliceous Mesocellular Foam: An Efficient Heterogeneous Catalyst for Chemically-Induced H2O Oxidation
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Materials Chemistry
Identifiers
urn:nbn:se:su:diva-96755 (URN)
Available from: 2013-11-26 Created: 2013-11-26 Last updated: 2013-11-26
5. Co-immobilization of an Enzyme and a Metal into the Compartments of Mesoporous Silica for Cooperative Tandem Catalysis: An Artificial Metalloenzyme
Open this publication in new window or tab >>Co-immobilization of an Enzyme and a Metal into the Compartments of Mesoporous Silica for Cooperative Tandem Catalysis: An Artificial Metalloenzyme
Show others...
2013 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 52, no 52, 14006-14010 p.Article in journal (Refereed) Published
Abstract [en]

Surpassing nature: A hybrid catalyst in which Candida antarctica lipase B and a nanopalladium species are co-immobilized into the compartments of mesoporous silica is presented. The metal nanoparticles and the enzyme are in close proximity to one another in the cavities of the support. The catalyst mimics a metalloenzyme and was used for dynamic kinetic resolution of a primary amine in high yield and excellent enantioselectivity.

Keyword
artificial deracemase, biocatalysis, dynamic kinetic resolution, hybrid catalysts, metal catalysis
National Category
Organic Chemistry
Identifiers
urn:nbn:se:su:diva-96701 (URN)10.1002/anie.201306487 (DOI)000328531100019 ()
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation
Note

AuthorCount: 7;

Available from: 2013-11-25 Created: 2013-11-25 Last updated: 2017-12-06Bibliographically approved

Open Access in DiVA

Comprehensive Summary(3650 kB)2246 downloads
File information
File name FULLTEXT02.pdfFile size 3650 kBChecksum SHA-512
c9be3f60fd863e2aab1d923eb092902f53f7c1bc5bf2dcba9ff081c69d06d3a6aacf4f462b5d79382951169f9b1e5ecbd5caff0388398d183bc3ca5dad20b55c
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Verho, Oscar
By organisation
Department of Organic Chemistry
Organic Chemistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 2246 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 236 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf