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
Mechanism of the palladium-catalyzed carbohydroxylation of allene-substituted conjugated dienes: rationalization of the recently observed nucleophilic attack by water on a (pi-allyl)palladium intermediate
Stockholm University, Faculty of Science, Department of Organic Chemistry.
Stockholm University, Faculty of Science, Department of Organic Chemistry.
2008 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 14, no 30, 9175-9180 p.Article in journal (Refereed) Published
Abstract [en]

The mechanism of the palladium-catalyzed oxidative carbohydroxylation of allene-substituted 1,3-cyclohexadiene was studied by DFT calculations. All intermediates and transition states of the reaction were identified and their structures were calculated. The calculations confirm the mechanism previously proposed and show that the CC bond-forming step occurs via insertion of one of the double bonds of 1,3-cyclohexadiene into a Pdvinyl bond of a vinylpalladium intermediate. This reaction leads to a (π-allyl)palladium intermediate, and coordination of benzoquinone and a double bond in the molecule to Pd creates a highly reactive cationic π-allyl complex, which is readily attacked by water according to the calculations.

Place, publisher, year, edition, pages
2008. Vol. 14, no 30, 9175-9180 p.
Keyword [en]
density functional calculations, homogeneous catalysis, palladium, water
National Category
Organic Chemistry
Identifiers
URN: urn:nbn:se:su:diva-14706DOI: 10.1002/chem.200801294ISI: 000260703900013OAI: oai:DiVA.org:su-14706DiVA: diva2:181226
Available from: 2008-12-03 Created: 2008-12-03 Last updated: 2017-12-13Bibliographically approved
In thesis
1. Catalysts for Oxygen Production and Utilization: Closing the Oxygen Cycle: From Biomimetic Oxidation to Artificial Photosynthesis
Open this publication in new window or tab >>Catalysts for Oxygen Production and Utilization: Closing the Oxygen Cycle: From Biomimetic Oxidation to Artificial Photosynthesis
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis describes the development and study of catalysts for redox reactions, which either utilize oxygen or hydrogen peroxide for the purpose of selectively oxidizing organic substrates, or produce oxygen as the necessary byproduct in the production of hydrogen by artificial photosynthesis.

The first chapter gives a general introduction about the use of environmentally friendly oxidants in the field of organic synthesis, and about the field of artificial photosynthesis. The second chapter describes a computational study of the mechanism of palladium-catalyzed oxidative carbohydroxylation of allene-substituted conjugated dienes. The proposed mechanism, which was supported by DFT calculations, involves an unusual water attack on a (π-allyl)palladium complex. The third chapter describes a computational study of the oxidation of unfunctionalized hydrocarbons, ethers and alcohols with hydrogen peroxide, catalyzed by methyltrioxorhenium (MTO). The mechanism was found to proceed via rate-limiting hydride abstraction followed by hydroxide transfer in a single concerted, but highly asynchronous, step as shown by intrinsic reaction coordinate (IRC) scans. The fourth chapter describes the use of a new hybrid (hydroquinone-Schiff base)cobalt catalyst as electron transfer mediator (ETM) in the palladium-catalyzed aerobic carbocyclization of enallenes. Covalently linking the two ETMs gave a fivefold rate increase compared to the use of separate components. The fifth chapter describes an improved synthetic route to the (hydroquinone-Schiff base)cobalt catalysts. Preparation of the key intermediate 5-(2,5-hydroxyphenyl)salicylaldehyde was improved by optimization of the key Suzuki coupling and change of protecting groups from methyl ethers to easily cleaved THP groups. The catalysts could thus be prepared in good overall yield from inexpensive starting materials.

Finally, the sixth chapter describes the preparation and study of two catalysts for water oxidation, both based on ligands containing imidazole groups, analogous to the histidine residues present in the oxygen evolving complex (OEC) and in many other metalloenzymes. The first, ruthenium-based, catalyst was found to catalyze highly efficient water oxidation induced by visible light. The second catalyst is, to the best of our knowledge, the first homogeneous manganese complex to catalyze light-driven water oxidation.

Place, publisher, year, edition, pages
Stockholm: Department of Organic Chemistry, Stockholm University, 2011. 65 p.
Keyword
oxygen, catalytic oxidation, biomimetic oxidation, artificial photosynthesis, water oxidation, DFT calculations
National Category
Organic Chemistry
Research subject
Organic Chemistry
Identifiers
urn:nbn:se:su:diva-56917 (URN)978-91-7447-289-9 (ISBN)
Public defence
2011-06-01, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 16 B, Stockholm, 10:00 (Swedish)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Accepted. Paper 6: Submitted.

Available from: 2011-05-10 Created: 2011-04-29 Last updated: 2012-09-27Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Karlsson, Erik A.Bäckvall, Jan-E.
By organisation
Department of Organic Chemistry
In the same journal
Chemistry - A European Journal
Organic Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 61 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