Frith, Abigail, Clarke, Aimee K., Heyam, Alex et al. (4 more authors) (2024) Silver-N-Heterocyclic Carbenes in π-Activation:Synergistic Effects between the Ligand Ring Size and the Anion. Organometallics. ISSN 0276-7333
Abstract
A series of 12 silver(I)-N-heterocyclic carbene (NHC) complexes were prepared featuring five- (both saturated and unsaturated backbone), six-, and seven-membered ring ligand scaffolds. The N-substituents of the NHCs were diisopropylphenyl in all cases, while the anion was varied between bromide, acetate, and triflate. The complexes were evaluated as catalysts in the spirocyclization of 1-(1H-indol-3-yl)-4-phenylbut-3-yn-2-one to give a spirocyclic indolenine product. To our knowledge, it is the first time that a systematic study has been conducted to examine the effects of both NHC ring size and anion in this type of silver-catalyzed reaction. While the acetate and triflate complexes catalyzed the reaction to 100% conversion, the bromide complexes exhibited a significant ligand/anion effect. Reactions catalyzed by both complexes bearing the five-membered ring NHC ligands and the complex bearing the seven-membered ring NHC ligand stalled after approximately two turnovers. However, the bromide complex bearing the six-membered ring NHC ligand catalyzes the reaction to almost full conversion, similarly to the acetate and triflate complexes. This demonstrates that the NHC ligand ring size can have a dramatic effect in these types of reactions and does not necessarily display a linear correlation.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | Funding Information: The project was funded through the EPSRC Dial-A-Molecule Interdisciplinary Mobility Fund and a Mary and Alice Smith Scholarship from the University of Leeds. Funding Information: The authors would like to thank the EPSRC Dial-A-Molecule Network and the Mary and Alice Smith Scholarship for funding. Publisher Copyright: © 2024 The Authors. Published by American Chemical Society. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) |
Depositing User: | Pure (York) |
Date Deposited: | 06 Mar 2024 16:30 |
Last Modified: | 14 Feb 2025 00:12 |
Published Version: | https://doi.org/10.1021/acs.organomet.3c00476 |
Status: | Published online |
Refereed: | Yes |
Identification Number: | 10.1021/acs.organomet.3c00476 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:209995 |
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Description: Silver−N-HeterocyclicCarbenesinπ−Activation:SynergisticEffectsbetweentheLigandRingSizeandtheAnion
Licence: CC-BY 2.5