<div class="csl-bib-body">
<div class="csl-entry">Weiser, M. (2023, July 10). <i>Continuous Enantioselective α-Alkylation of Ketones via Direct Enamine Photoexcitation</i> [Poster Presentation]. 22nd European Symposium on Organic Chemistry 2023, Belgium.</div>
</div>
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dc.identifier.uri
http://hdl.handle.net/20.500.12708/191822
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dc.description.abstract
The persistent difficulty of asymmetric catalytic direct intermolecular α-alkylation reactions of ketones with simple alkyl halides restricts access to many complex products in nature and explains its scarcity in photocatalytic processes. Inspired by the pioneering work of Melchiorre, we developed a new photo/organocatalytic strategy to achieve this synthetic task.
The highly abundant and natural-derived 9-amino(9-deoxy)-epi-cinchona alkaloids with a phenyl group in the 2-position acted as potent catalysts for the direct photo/organocatalytic asymmetric α-alkylation of ketones. After parameter optimization, diverse functionalized symmetric and cyclic ketones of different ring sizes could readily react with symmetric electron-deficient bromomalonates, and the related products could be obtained with good yield and enantioselectivity. Furthermore, this concept provided access to both enantiomeric antipodes. Mechanistic investigations revealed the proposed reaction mechanism, which proceeds via a self-propagating radical chain mechanism initiated by the direct excitation of the transiently formed secondary enamine upon 365 nm irradiation. Apart from an uncomplicated procedure optimized for batch, homogeneous conditions were found that enabled the photo-/organocatalytic synthesis of 1,3-diethyl-2-(2-oxocyclohexyl)propanedioate in continuous flow with good productivity and enantioselectivity.
en
dc.language.iso
en
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dc.subject
photocatalysis
en
dc.subject
alkylation
en
dc.subject
enantioselective synthesis
en
dc.subject
continuous flow
en
dc.title
Continuous Enantioselective α-Alkylation of Ketones via Direct Enamine Photoexcitation
en
dc.type
Presentation
en
dc.type
Vortrag
de
dc.type.category
Poster Presentation
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tuw.researchTopic.id
M6
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tuw.researchTopic.name
Biological and Bioactive Materials
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tuw.researchTopic.value
100
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tuw.publication.orgunit
E163-03-5 - Forschungsgruppe Nachhaltige organische Synthese und Katalyse
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tuw.event.name
22nd European Symposium on Organic Chemistry 2023
en
dc.description.sponsorshipexternal
European Union’s Horizon 2020
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dc.relation.grantnoexternal
864991
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tuw.event.startdate
09-07-2023
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tuw.event.enddate
13-07-2023
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tuw.event.online
On Site
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tuw.event.type
Event for scientific audience
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tuw.event.country
BE
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tuw.event.presenter
Weiser, Michael
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wb.sciencebranch
Chemie
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wb.sciencebranch.oefos
1040
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wb.sciencebranch.value
100
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item.languageiso639-1
en
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item.openairetype
conference poster not in proceedings
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item.grantfulltext
none
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item.fulltext
no Fulltext
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item.cerifentitytype
Publications
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item.openairecristype
http://purl.org/coar/resource_type/c_18co
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crisitem.author.dept
E163-03-5 - Forschungsgruppe Nachhaltige organische Synthese und Katalyse
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crisitem.author.parentorg
E163-03 - Forschungsbereich Organische und Biologische Chemie
