uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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
The Missing C-1-C-5 Cycloaromatization Reaction: Triplet State Antiaromaticity Relief and Self-Terminating Photorelease of Formaldehyde for Synthesis of Fulvenes from Enynes
Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32310 USA..
Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32310 USA..
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32310 USA..
Show others and affiliations
2015 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 137, no 49, p. 15441-15450Article in journal (Refereed) Published
Resource type
Text
Abstract [en]

The last missing example of the four archetypical cycloaromatizations of enediynes and enynes was discovered by combining a twisted alkene excited state with a new self-terminating path for intramolecular conversion of diradicals into closed-shell products. Photoexcitation of aromatic enynes to a twisted alkene triplet state creates a unique stereoelectronic situation, which is facilitated by the relief of excited state antiaromaticity of the benzene ring. This enables the usually unfavorable 5-endo-trig cyclization and merges it with 5-exo-dig closure. The 1,4-diradical product of the C1-C5 cyclization undergoes internal H atom transfer that is coupled with the fragmentation of an exocyclic C-C bond. This sequence provides efficient access to benzofulvenes from enynes and expands the utility of self-terminating aromatizing enyne cascades to photochemical reactions. The key feature of this self-terminating reaction is that, despite the involvement of radical species in the key cyclization step, no external radical sources or quenchers are needed to provide the products. In these cascades, both radical centers are formed transiently and converted to the closed-shell products via intramolecular H-transfer and C-C bond fragmentation. Furthermore, incorporating C-C bond cleavage into the photochemical self-terminating cyclizations of enynes opens a new way for the use of alkenes as alkyne equivalents in organic synthesis.

Place, publisher, year, edition, pages
2015. Vol. 137, no 49, p. 15441-15450
National Category
Physical Chemistry Organic Chemistry
Identifiers
URN: urn:nbn:se:uu:diva-274447DOI: 10.1021/jacs.5b07448ISI: 000366874700026OAI: oai:DiVA.org:uu-274447DiVA, id: diva2:896476
Funder
Swedish Research Council, 621-2011-4177Swedish National Infrastructure for Computing (SNIC)
Available from: 2016-01-21 Created: 2016-01-21 Last updated: 2018-04-23Bibliographically approved
In thesis
1. Influence of Aromaticity on Excited State Structure, Reactivity and Properties
Open this publication in new window or tab >>Influence of Aromaticity on Excited State Structure, Reactivity and Properties
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis describes work that could help development of new photochemical reactions and light-absorbing materials. Focus is on the chemical concept "aromaticity" which is a proven conceptual tool in developing thermal chemical reactions. It is here shown that aromaticity is also valuable for photochemistry. The influence of aromaticity is discussed in terms of structure, reactivity and properties. With regard to structure, it is found that photoexcited molecules change their structure to attain aromatic stabilization (planarize, allow through-space conjugation) or avoid antiaromatic destabilization (pucker). As for reactivity, it is found that stabilization/destabilization of reactants decrease/increase photoreactivity, in accordance with the Bell-Evans-Polanyi relationship. Two photoreactions based on excited state antiaromatic destabilization of the substrates are reported. Finally, with respect to properties, it is shown that excited state energies can be tuned by considering aromatic effects of both the electronic ground state and the electronically excited states. The fundamental research presented in this thesis forms a foundation for the development of new photochemical reactions and design of compounds for new organic electronic materials.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2018. p. 55
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1679
Keyword
photochemistry, aromaticity, computational chemistry
National Category
Organic Chemistry Theoretical Chemistry
Research subject
Chemistry with specialization in Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-349229 (URN)978-91-513-0354-3 (ISBN)
Public defence
2018-06-14, room 80101, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2018-05-22 Created: 2018-04-23 Last updated: 2018-05-22

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Jorner, KjellOttosson, Henrik

Search in DiVA

By author/editor
Jorner, KjellOttosson, Henrik
By organisation
Department of Chemistry - BMCDepartment of Chemistry - Ångström
In the same journal
Journal of the American Chemical Society
Physical ChemistryOrganic Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 660 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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