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Professor Ann O'Donoghue's Outputs (34)

S ‐Aryl Substitution Enhances Acidity of the 1,2,4‐Triazolium Scaffold (2024)
Journal Article
Smith, M. S., Blundell, T. J., Hickson, I., & O'Donoghue, A. C. (online). S ‐Aryl Substitution Enhances Acidity of the 1,2,4‐Triazolium Scaffold. European Journal of Organic Chemistry, https://doi.org/10.1002/ejoc.202400753

The 1,2,4‐triazolium scaffold in asymmetric organocatalysis results in remarkable rate accelerations, with reactions typically occurring via N‐heterocyclic carbene (NHC) intermediates. Although the most acidic NHC pre‐catalyst class, there remains sc... Read More about S ‐Aryl Substitution Enhances Acidity of the 1,2,4‐Triazolium Scaffold.

Going Full Circle with Organocatalysis and Biocatalysis: The Latent Potential of Cofactor Mimics in Asymmetric Synthesis (2023)
Journal Article
Murray, J., Hodgson, D. R., & O’Donoghue, A. C. (2023). Going Full Circle with Organocatalysis and Biocatalysis: The Latent Potential of Cofactor Mimics in Asymmetric Synthesis. Journal of Organic Chemistry, 88(12), 7619–7629. https://doi.org/10.1021/acs.joc.2c02747

Many enzymes work in tandem with small molecule cofactors, which have inspired organocatalyst designs. Chemical modification of cofactor scaffolds has increased organocatalytic reactivity and reaction scope. This synopsis presents a selection of rece... Read More about Going Full Circle with Organocatalysis and Biocatalysis: The Latent Potential of Cofactor Mimics in Asymmetric Synthesis.

Rate and equilibrium constants for the addition of triazolium salt derived N-heterocyclic carbenes to heteroaromatic aldehydes (2022)
Journal Article
Duan, Z., Young, C. M., Zhu, J., Slawin, A. M., O'Donoghue, A. C., & Smith, A. D. (2023). Rate and equilibrium constants for the addition of triazolium salt derived N-heterocyclic carbenes to heteroaromatic aldehydes. Chemical Science, 14(1), 162-170. https://doi.org/10.1039/d2sc05704b

Heteroaromatic aldehydes are often used preferentially or exclusively in a range of NHC-catalysed processes that proceed through the generation of a reactive diaminoenol or Breslow Intermediate (BI), with the reason for their unique reactivity curren... Read More about Rate and equilibrium constants for the addition of triazolium salt derived N-heterocyclic carbenes to heteroaromatic aldehydes.

The Role of the Fused Ring in Bicyclic Triazolium Organocatalysts: Kinetic, X-ray, and DFT Insights (2022)
Journal Article
Zhu, J., Moreno, I., Quinn, P., Yufit, D. S., Song, L., Young, C. M., Duan, Z., Tyler, A. R., Waddell, P. G., Hall, M. J., Probert, M. R., Smith, A. D., & O’Donoghue, A. C. (2022). The Role of the Fused Ring in Bicyclic Triazolium Organocatalysts: Kinetic, X-ray, and DFT Insights. Journal of Organic Chemistry, 87(6), 4241-4253. https://doi.org/10.1021/acs.joc.1c03073

Bicyclic triazolium scaffolds are widely employed in N-heterocyclic carbene (NHC) organocatalysis. While the incorporation of a fused ring was initially for synthetic utility in accessing chiral, modular triazolyl scaffolds, recent results highlight... Read More about The Role of the Fused Ring in Bicyclic Triazolium Organocatalysts: Kinetic, X-ray, and DFT Insights.

Triazolium Salt Organocatalysis: Mechanistic Evaluation of Unusual Ortho-Substituent Effects on Deprotonation (2021)
Journal Article
Quinn, P., Smith, M. S., Zhu, J., Hodgson, D. R., & O’Donoghue, A. C. (2021). Triazolium Salt Organocatalysis: Mechanistic Evaluation of Unusual Ortho-Substituent Effects on Deprotonation. Catalysts, 11(9), Article 1055. https://doi.org/10.3390/catal11091055

Organocatalysis by N-heterocyclic carbenes is normally initiated by the deprotonation of precursor azolium ions to form active nucleophilic species. Substituent effects on deprotonation have an impact on catalytic efficiency and provide insight into... Read More about Triazolium Salt Organocatalysis: Mechanistic Evaluation of Unusual Ortho-Substituent Effects on Deprotonation.

Kinetic and Structure–Activity Studies of the Triazolium Ion– catalyzed Intramolecular Stetter Reaction (2021)
Journal Article
Collett, C. J., Young, C. M., Massey, R. S., O'Donoghue, A. C., & Smith, A. D. (2021). Kinetic and Structure–Activity Studies of the Triazolium Ion– catalyzed Intramolecular Stetter Reaction. European Journal of Organic Chemistry, 2021(26), 3670-3675. https://doi.org/10.1002/ejoc.202100384

Mechanistic studies of the triazolium ion-catalyzed intramolecular Stetter reaction using initial rates analysis in NEt3/NEt3HCl buffered methanol showed the reaction to be first-order in catalyst and zero-order in aldehyde over a broad range of ald... Read More about Kinetic and Structure–Activity Studies of the Triazolium Ion– catalyzed Intramolecular Stetter Reaction.

Kinetic and structure–activity studies of the triazolium ion-catalysed benzoin condensation (2020)
Journal Article
Massey, R. S., Murray, J., Collett, C. J., Zhu, J., Smith, A. D., & O'Donoghue, A. C. (2021). Kinetic and structure–activity studies of the triazolium ion-catalysed benzoin condensation. Organic and Biomolecular Chemistry, 19(2), 387-393. https://doi.org/10.1039/d0ob02207a

Steady-state kinetic and structure–activity studies of a series of six triazolium-ion pre-catalysts 2a–2f were investigated for the benzoin condensation. These data provide quantitative insight into the role of triazolium N-aryl substitution under sy... Read More about Kinetic and structure–activity studies of the triazolium ion-catalysed benzoin condensation.

Unusually high α-proton acidity of prolyl residues in cyclic peptides (2020)
Journal Article
Maguire, O. R., Taylor, B., Higgins, E. M., Rees, M., Cobb, S. L., Simpkins, N. S., Hayes, C. J., & O'Donoghue, A. C. (2020). Unusually high α-proton acidity of prolyl residues in cyclic peptides. Chemical Science, 11(29), 7722-7729. https://doi.org/10.1039/d0sc02508a

The acidity of the α-proton in peptides has an essential role in numerous biochemical reactions and underpins their stereochemical integrity, which is critical to their biological function. We report a detailed kinetic and computational study of the... Read More about Unusually high α-proton acidity of prolyl residues in cyclic peptides.

N-Terminal speciation for native chemical ligation (2020)
Journal Article
Maguire, O. R., Zhu, J., Brittain, W. D., Hudson, A. S., Cobb, S. L., & O’Donoghue, A. C. (2020). N-Terminal speciation for native chemical ligation. Chemical Communications, 56(45), 6114-6117. https://doi.org/10.1039/d0cc01604g

Native chemical ligation (NCL) enables the chemical synthesis of peptides via reactions between N-terminal thiolates and C-terminal thioesters under mild, aqueous conditions at pH 7–8. Here we demonstrate quantitatively how thiol speciation at N-term... Read More about N-Terminal speciation for native chemical ligation.

The identification of carbon dioxide mediated protein post-translational modifications (2018)
Journal Article
Linthwaite, V., Janus, J., Brown, A., Wong-Pascua, D., O’Donoghue, A., Porter, A., Treumann, A., Hodgson, D., & Cann, M. (2018). The identification of carbon dioxide mediated protein post-translational modifications. Nature Communications, 9, Article 3092. https://doi.org/10.1038/s41467-018-05475-z

Carbon dioxide is vital to the chemistry of life processes including metabolism, cellular homoeostasis, and pathogenesis. CO2 is generally unreactive but can combine with neutral amines to form carbamates on proteins under physiological conditions. T... Read More about The identification of carbon dioxide mediated protein post-translational modifications.

New Blatter-type radicals from a bench-stable carbene (2017)
Journal Article
Grant, J. A., Lu, Z., Tucker, D. E., Hockin, B. M., Yufit, D. S., Fox, M. A., …O'Donoghue, A. C. (2017). New Blatter-type radicals from a bench-stable carbene. Nature Communications, 8, Article 15088. https://doi.org/10.1038/ncomms15088

Stable benzotriazinyl radicals (Blatter’s radicals) recently attracted considerable interest as building blocks for functional materials. The existing strategies to derivatize Blatter’s radicals are limited, however, and synthetic routes are complex.... Read More about New Blatter-type radicals from a bench-stable carbene.

The Synthesis, Conformation and Hydrolytic Stability of an N,S-bridging Thiophosphoramidate Analogue of Thymidylyl-3ʹ,5ʹ-Thymidine (2016)
Journal Article
Conway, L., Mikkola, S., O’Donoghue, A., & Hodgson, D. (2016). The Synthesis, Conformation and Hydrolytic Stability of an N,S-bridging Thiophosphoramidate Analogue of Thymidylyl-3ʹ,5ʹ-Thymidine. Organic and Biomolecular Chemistry, 14(30), 7361-7367. https://doi.org/10.1039/c6ob01270a

A 3'-N,5'-S-bridging thiophosphoramidate analogue of thymidylyl-3ʹ,5ʹ-thymidine was synthesised under aqueous conditions. 1H NMR conformational measurements show that the 3'-N-substituted deoxyribose ring is biased towards the 'north', RNA-like confo... Read More about The Synthesis, Conformation and Hydrolytic Stability of an N,S-bridging Thiophosphoramidate Analogue of Thymidylyl-3ʹ,5ʹ-Thymidine.

Proton transfer reactions of a bridged bis-propyl bis-imidazolium salt (2016)
Journal Article
Massey, R. S., Quinn, P., Zhou, S., Murphy, J. A., & O'Donoghue, A. C. (2016). Proton transfer reactions of a bridged bis-propyl bis-imidazolium salt. Journal of Physical Organic Chemistry, 29(12), 735-740. https://doi.org/10.1002/poc.3567

Tetraazafulvalene 1 has found broad application in reduction and other related transformations and is conveniently generated from bis-propyl bis-imidazolium salt 4 with a strong base in a non-protic solvent. The proposed mechanism for the formation o... Read More about Proton transfer reactions of a bridged bis-propyl bis-imidazolium salt.

Synthesis, applications and mechanistic investigations of C2 symmetric guanidinium salts (2015)
Journal Article
Allingham, M., Bennett, E., Davies, D., Harper, P., Howard-Jones, A., Mehdar, Y., …O’Donoghue, A. (2016). Synthesis, applications and mechanistic investigations of C2 symmetric guanidinium salts. Tetrahedron, 72(4), 496-503. https://doi.org/10.1016/j.tet.2015.11.058

A range of guanidinium catalysts was prepared in six or seven synthetic steps and applied to the phase transfer alkylation of a glycinate Schiff's base in 21–86% ee as well as the phase transfer epoxidation of some chalcones in 85–94% ee. Using a spe... Read More about Synthesis, applications and mechanistic investigations of C2 symmetric guanidinium salts.

Homogeneous Acid Catalysis in Nonasymmetric Synthesis (2015)
Book Chapter
Maguire, O., & O'Donoghue, A. (2015). Homogeneous Acid Catalysis in Nonasymmetric Synthesis. In M. North (Ed.), Sustainable catalysis : without metals or other endangered elements. Part 1 (38-64). Royal Society of Chemistry. https://doi.org/10.1039/9781782622093-00038

Homogeneous acid catalysis of nonasymmetric reactions continues to be an area of significant focus, and this chapter concentrates on recent relevant advances within a green chemistry context. The developments in acid catalysis are viewed through a nu... Read More about Homogeneous Acid Catalysis in Nonasymmetric Synthesis.

Understanding Thio-Effects in Simple Phosphoryl Systems: Role of Solvent Effects and Nucleophile Charge (2015)
Journal Article
Carvalho, A., O’Donoghue, A., Hodgson, D., & Kamerlin, S. (2015). Understanding Thio-Effects in Simple Phosphoryl Systems: Role of Solvent Effects and Nucleophile Charge. Organic and Biomolecular Chemistry, 13(19), 5391-5398. https://doi.org/10.1039/c5ob00309a

Recent experimental work (J. Org. Chem., 2012, 77, 5829) demonstrated pronounced differences in measured thio-effects for the hydrolysis of (thio)phosphodichloridates by water and hydroxide nucleophiles. In the present work, we have performed detaile... Read More about Understanding Thio-Effects in Simple Phosphoryl Systems: Role of Solvent Effects and Nucleophile Charge.

Rate and Equilibrium Constants for the Addition of N-Heterocyclic Carbenes into Benzaldehydes: A Remarkable 2-Substituent Effect (2015)
Journal Article
Collett, C., Massey, R., Taylor, J., Maguire, O., O'Donoghue, A., & Smith, A. (2015). Rate and Equilibrium Constants for the Addition of N-Heterocyclic Carbenes into Benzaldehydes: A Remarkable 2-Substituent Effect. Angewandte Chemie International Edition, 54(23), 6887-6892. https://doi.org/10.1002/anie.201501840

Rate and equilibrium constants for the reaction between N-aryl triazolium N-heterocyclic carbene (NHC) precatalysts and substituted benzaldehyde derivatives to form 3-(hydroxybenzyl)azolium adducts under both catalytic and stoichiometric conditions h... Read More about Rate and Equilibrium Constants for the Addition of N-Heterocyclic Carbenes into Benzaldehydes: A Remarkable 2-Substituent Effect.

Proton transfer reactions of N-aryl triazolium salts: unusual ortho-substituent effects (2014)
Journal Article
Tucker, D., Quinn, P., Massey, R., Collett, C., Jasiewicz, D., Bramley, C., …O'Donoghue, A. (2015). Proton transfer reactions of N-aryl triazolium salts: unusual ortho-substituent effects. Journal of Physical Organic Chemistry, 28(2), 108-115. https://doi.org/10.1002/poc.3399

Previous studies of the C(3)-hydrogen/deuterium exchange reactions of the triazolium ion conjugate acids of triazolyl N-heterocyclic carbenes revealed a change of mechanism under acidic conditions with N1-protonation to a dicationic salt. Interesting... Read More about Proton transfer reactions of N-aryl triazolium salts: unusual ortho-substituent effects.

Enzyme Architecture: The Effect of Replacement and Deletion Mutations of Loop 6 on Catalysis by Triosephosphate Isomerase (2014)
Journal Article
Zhai, X., Go, M., O'Donoghue, A., Amyes, T., Pegan, S., Wang, Y., …Richard, J. (2014). Enzyme Architecture: The Effect of Replacement and Deletion Mutations of Loop 6 on Catalysis by Triosephosphate Isomerase. Biochemistry, 53(21), 3486-3501. https://doi.org/10.1021/bi500458t

Two mutations of the phosphodianion gripper loop in chicken muscle triosephosphate isomerase (cTIM) were examined: (1) the loop deletion mutant (LDM) formed by removal of residues 170–173 [Pompliano, D. L., et al. (1990) Biochemistry 29, 3186–3194] a... Read More about Enzyme Architecture: The Effect of Replacement and Deletion Mutations of Loop 6 on Catalysis by Triosephosphate Isomerase.