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Dale HA, Hodges GR, Lloyd-Jones GC. Kinetics and Mechanism of Azole n-π*-Catalyzed Amine Acylation. J Am Chem Soc 2023; 145:18126-18140. [PMID: 37526380 PMCID: PMC10436283 DOI: 10.1021/jacs.3c06258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Indexed: 08/02/2023]
Abstract
Azole anions are highly competent in the activation of weak acyl donors, but, unlike neutral (aprotic) Lewis bases, are not yet widely applied as acylation catalysts. Using a combination of in situ and stopped-flow 1H/19F NMR spectroscopy, kinetics, isotopic labeling, 1H DOSY, and electronic structure calculations, we have investigated azole-catalyzed aminolysis of p-fluorophenyl acetate. The global kinetics have been elucidated under four sets of conditions, and the key elementary steps underpinning catalysis deconvoluted using a range of intermediates and transition state probes. While all evidence points to an overarching mechanism involving n-π* catalysis via N-acylated azole intermediates, a diverse array of kinetic regimes emerges from this framework. Even seemingly minor changes to the solvent, auxiliary base, or azole catalyst can elicit profound changes in the temporal evolution, thermal sensitivity, and progressive inhibition of catalysis. These observations can only be rationalized by taking a holistic view of the mechanism and a set of limiting regimes for the kinetics. Overall, the analysis of 18 azole catalysts spanning nearly 10 orders of magnitude in acidity highlights the pitfall of pursuing ever more nucleophilic catalysts without regard for catalyst speciation.
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Affiliation(s)
- Harvey
J. A. Dale
- EaStChem, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K.
| | - George R. Hodges
- Jealott’s
Hill International Research Centre, Syngenta, Bracknell, Berkshire RG42 6EY, U.K.
| | - Guy C. Lloyd-Jones
- EaStChem, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K.
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2
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Smith SM, Greenhalgh MD, Feoktistova T, Walden DM, Taylor JE, Cordes DB, Slawin AMZ, Cheong PH, Smith AD. Scope, Limitations and Mechanistic Analysis of the HyperBTM‐Catalyzed Acylative Kinetic Resolution of Tertiary Heterocyclic Alcohols**. European J Org Chem 2022. [DOI: 10.1002/ejoc.202101111] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Samuel M. Smith
- EaStCHEM School of Chemistry University of St Andrews North Haugh, St Andrews, Fife KY16 9ST UK
| | - Mark D. Greenhalgh
- EaStCHEM School of Chemistry University of St Andrews North Haugh, St Andrews, Fife KY16 9ST UK
- Department of Chemistry University of Warwick Coventry CV4 7AL UK
| | - Taisiia Feoktistova
- Department of Chemistry Oregon State University 153 Gilbert Hall Corvallis OR 97331 USA
| | - Daniel M. Walden
- Department of Chemistry Oregon State University 153 Gilbert Hall Corvallis OR 97331 USA
| | - James E. Taylor
- EaStCHEM School of Chemistry University of St Andrews North Haugh, St Andrews, Fife KY16 9ST UK
- Department of Chemistry University of Bath Claverton Down, Bath BA2 7AY UK
| | - David B. Cordes
- EaStCHEM School of Chemistry University of St Andrews North Haugh, St Andrews, Fife KY16 9ST UK
| | - Alexandra M. Z. Slawin
- EaStCHEM School of Chemistry University of St Andrews North Haugh, St Andrews, Fife KY16 9ST UK
| | - Paul Ha‐Yeon Cheong
- Department of Chemistry Oregon State University 153 Gilbert Hall Corvallis OR 97331 USA
| | - Andrew D. Smith
- EaStCHEM School of Chemistry University of St Andrews North Haugh, St Andrews, Fife KY16 9ST UK
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3
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Maji R, Ugale H, Wheeler SE. Understanding the Reactivity and Selectivity of Fluxional Chiral DMAP-Catalyzed Kinetic Resolutions of Axially Chiral Biaryls. Chemistry 2019; 25:4452-4459. [PMID: 30657217 DOI: 10.1002/chem.201806068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/17/2019] [Indexed: 12/17/2022]
Abstract
Fluxional chiral DMAP-catalyzed kinetic resolutions of axially chiral biaryls were examined using density functional theory. Computational analyses lead to a revised understanding of this reaction in which the interplay of numerous non-covalent interactions control the conformation and flexibility of the active catalyst, the preferred mechanism, and the stereoselectivity. Notably, while the DMAP catalyst itself is confirmed to be highly fluxional, electrostatically driven π⋅⋅⋅π+ interactions render the active, acylated form of the catalyst highly rigid, explaining its pronounced stereoselectivity.
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Affiliation(s)
- Rajat Maji
- Department of Chemistry, Texas A&M University, College Station, TX, 77842, USA
| | - Heena Ugale
- Department of Chemistry, Texas A&M University, College Station, TX, 77842, USA
| | - Steven E Wheeler
- Department of Chemistry, Texas A&M University, College Station, TX, 77842, USA.,Center for Computational Quantum Chemistry, Department of Chemistry, University of Georgia, Athens, GA, 30602, USA
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4
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Abstract
Naked-eye comparison of reaction profiles is a powerful tool to extract mechanistic information – FAQ, video tutorial and templated examples included.
Visual kinetic analyses extract meaningful mechanistic information from experimental data using the naked-eye comparison of appropriately modified progress reaction profiles. Basic kinetic information is obtained easily and quickly from just a few experiments. Therefore, these methods are valuable tools for all chemists working in process chemistry, synthesis or catalysis with an interest in mechanistic studies. This minireview describes the visual kinetic analyses developed in the last fifteen years and provides answers to the most common queries of new users. Furthermore, a video tutorial is attached detailing the implementation of both VTNA and RPKA.
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Affiliation(s)
| | - Jordi Burés
- School of Chemistry , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK . ; Tel: +44 (0)161 275 4634
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5
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Affiliation(s)
- Shinji Yamada
- Department of Chemistry, Faculty of Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan
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6
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Korolyova MA, Vakarov SA, Kozhevnikov DN, Gruzdev DA, Levit GL, Krasnov VP. Mutual Kinetic Resolution of Racemic 3,4-Dihydro-3-methyl-2H
-[1,4]benzoxazines with Acyl Chlorides of Racemic O
-Phenyllactic Acids and DFT Modelling of Transition States. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800656] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Marina A. Korolyova
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch); 22/20 S. Kovalevskoy/Akademicheskaya St. 620990 Ekaterinburg Russia
| | - Sergey A. Vakarov
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch); 22/20 S. Kovalevskoy/Akademicheskaya St. 620990 Ekaterinburg Russia
| | - Dmitry N. Kozhevnikov
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch); 22/20 S. Kovalevskoy/Akademicheskaya St. 620990 Ekaterinburg Russia
| | - Dmitry A. Gruzdev
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch); 22/20 S. Kovalevskoy/Akademicheskaya St. 620990 Ekaterinburg Russia
| | - Galina L. Levit
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch); 22/20 S. Kovalevskoy/Akademicheskaya St. 620990 Ekaterinburg Russia
| | - Victor P. Krasnov
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch); 22/20 S. Kovalevskoy/Akademicheskaya St. 620990 Ekaterinburg Russia
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7
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Cozett RE, Venter GA, Gokada MR, Hunter R. Catalytic enantioselective acyl transfer: the case for 4-PPY with a C-3 carboxamide peptide auxiliary based on synthesis and modelling studies. Org Biomol Chem 2018; 14:10914-10925. [PMID: 27814425 DOI: 10.1039/c6ob01991a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A series of 4-pyrrolidinopyridine (4-PPY) C-3 carboxamides containing peptide-based side chains have been synthesised and evaluated in the kinetic resolution of a small library of chiral benzylic secondary alcohols. A key design element was the incorporation of a tryptophan residue in the peptide side chain for promoting π-stacking between peptide side chain and the pyridinium ring of the N-acyl intermediate, in which modelling was used as a structure-based guiding tool. Together, a catalyst containing a LeuTrp-N-Boc side chain (catalyst 8) was identified that achieved s-values up to and in slight excess of 10. A transition-state model based on the modelling is proposed to explain the origin of enantioselectivity. This study establishes the usefulness of modelling as a structure-based guiding tool for enantioselectivity optimization as well as the potential for developing scalable peptide-based DMAP-type catalysts for large-scale resolution work.
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Affiliation(s)
- Rudy E Cozett
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa.
| | - Gerhard A Venter
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa. and Scientific Computing Research Unit, University of Cape Town, Rondebosch, 7701, South Africa
| | - Maheswara Rao Gokada
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa.
| | - Roger Hunter
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa.
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8
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Panahi F, Fareghi-Alamdari R, Khajeh Dangolani S, Khalafi-Nezhad A, Golestanzadeh M. Graphene GraftedN-Methyl-4-pyridinamine (G-NMPA): An Efficient Heterogeneous Organocatalyst for Acetylation of Alcohols. ChemistrySelect 2017. [DOI: 10.1002/slct.201601578] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Farhad Panahi
- Department of Polymer Engineering and Color Technology; Amirkabir University of Technology; Tehran Iran
- Department of Chemistry, College of Sciences; Shiraz University; Shiraz 71454 Iran
| | - Reza Fareghi-Alamdari
- Faculty of Chemistry & Chemical Engineering; Malek-Ashtar University of Technology; Tehran Iran
| | | | - Ali Khalafi-Nezhad
- Department of Chemistry, College of Sciences; Shiraz University; Shiraz 71454 Iran
| | - Mohsen Golestanzadeh
- Department of Organic Chemistry, Faculty of Chemistry; University of Kashan; Kashan Iran
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9
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Young CM, Stark DG, West TH, Taylor JE, Smith AD. Exploiting the Imidazolium Effect in Base-free Ammonium Enolate Generation: Synthetic and Mechanistic Studies. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201608046] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Claire M. Young
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
| | - Daniel G. Stark
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
| | - Thomas H. West
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
| | - James E. Taylor
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
| | - Andrew D. Smith
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
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10
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Young CM, Stark DG, West TH, Taylor JE, Smith AD. Exploiting the Imidazolium Effect in Base-free Ammonium Enolate Generation: Synthetic and Mechanistic Studies. Angew Chem Int Ed Engl 2016; 55:14394-14399. [DOI: 10.1002/anie.201608046] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 09/22/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Claire M. Young
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
| | - Daniel G. Stark
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
| | - Thomas H. West
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
| | - James E. Taylor
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
| | - Andrew D. Smith
- EaStCHEM, School of Chemistry; University of St Andrews; North Haugh St Andrews Fife KY16 9ST UK
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11
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Panahi F, Dangolani SK, Khalafi-Nezhad A. Synthesis of a Novel Magnetic Reusable Organocatalyst Based on 4-Dialkylaminopyridines for Acyl Transformations. ChemistrySelect 2016. [DOI: 10.1002/slct.201600824] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Farhad Panahi
- Department of Chemistry; College of Sciences; Shiraz 71454, Iran Iran
- Department of Polymer Engineering and Color Technology; Amirkabir University of Technology; Tehran Iran
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12
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Dangolani SK, Panahi F, Nourisefat M, Khalafi-Nezhad A. 4-Dialkylaminopyridine modified magnetic nanoparticles: as an efficient nano-organocatalyst for one-pot synthesis of 2-amino-4H-chromene-3-carbonitrile derivatives in water. RSC Adv 2016. [DOI: 10.1039/c6ra18078g] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A new DMAP-based magnetic nano-organocatalyst was developed for efficient one-pot synthesis of 2-amino-4H-chromene-3-carbonitrile derivatives in water as a green solvent.
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Affiliation(s)
| | - Farhad Panahi
- Department of Polymer Engineering and Color Technology
- Amirkabir University of Technology
- Tehran
- Iran
| | - Maryam Nourisefat
- Department of Chemistry
- College of Sciences
- Shiraz University
- Shiraz 71454
- Iran
| | - Ali Khalafi-Nezhad
- Department of Chemistry
- College of Sciences
- Shiraz University
- Shiraz 71454
- Iran
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