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Roagna G, Ascough DMH, Ibba F, Vicini AC, Fontana A, Christensen KE, Peschiulli A, Oehlrich D, Misale A, Trabanco AA, Paton RS, Pupo G, Gouverneur V. Hydrogen Bonding Phase-Transfer Catalysis with Ionic Reactants: Enantioselective Synthesis of γ-Fluoroamines. J Am Chem Soc 2020; 142:14045-14051. [PMID: 32608977 PMCID: PMC7441491 DOI: 10.1021/jacs.0c05131] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
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Ammonium
salts are used as phase-transfer catalysts for fluorination
with alkali metal fluorides. We now demonstrate that these organic
salts, specifically azetidinium triflates, are suitable substrates
for enantioselective ring opening with CsF and a chiral bis-urea catalyst. This process, which highlights the ability of hydrogen
bonding phase-transfer catalysts to couple two ionic reactants, affords
enantioenriched γ-fluoroamines in high yields. Mechanistic studies
underline the role of the catalyst for phase-transfer, and computed
transition state structures account for the enantioconvergence observed
for mixtures of achiral azetidinium diastereomers. The N-substituents
in the electrophile influence the reactivity, but the configuration
at nitrogen is unimportant for the enantioselectivity.
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Affiliation(s)
- Giulia Roagna
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - David M H Ascough
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Francesco Ibba
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Anna Chiara Vicini
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Alberto Fontana
- Discovery Chemistry, Janssen Research & Development, Janssen-Cilag S.A., Calle Jarama 75A, 45007 Toledo, Spain
| | - Kirsten E Christensen
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Aldo Peschiulli
- Discovery Sciences Medicinal Chemistry, Janssen Research & Development, Janssen Pharmaceutica N.V., Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Daniel Oehlrich
- Discovery Sciences Medicinal Chemistry, Janssen Research & Development, Janssen Pharmaceutica N.V., Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Antonio Misale
- Discovery Chemistry, Janssen Research & Development, Janssen-Cilag S.A., Calle Jarama 75A, 45007 Toledo, Spain
| | - Andrés A Trabanco
- Discovery Chemistry, Janssen Research & Development, Janssen-Cilag S.A., Calle Jarama 75A, 45007 Toledo, Spain
| | - Robert S Paton
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K.,Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Gabriele Pupo
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Véronique Gouverneur
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
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Schiedel M, Moroglu M, Ascough DMH, Chamberlain AER, Kamps JJAG, Sekirnik AR, Conway SJ. Chemical Epigenetics: The Impact of Chemical and Chemical Biology Techniques on Bromodomain Target Validation. Angew Chem Int Ed Engl 2019; 58:17930-17952. [DOI: 10.1002/anie.201812164] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 01/08/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Matthias Schiedel
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Mustafa Moroglu
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA UK
| | - David M. H. Ascough
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Anna E. R. Chamberlain
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Jos J. A. G. Kamps
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Angelina R. Sekirnik
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Stuart J. Conway
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA UK
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3
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Schiedel M, Moroglu M, Ascough DMH, Chamberlain AER, Kamps JJAG, Sekirnik AR, Conway SJ. Chemische Epigenetik: der Einfluss chemischer und chemo‐biologischer Techniken auf die Zielstruktur‐Validierung von Bromodomänen. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201812164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Matthias Schiedel
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA Großbritannien
| | - Mustafa Moroglu
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA Großbritannien
| | - David M. H. Ascough
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA Großbritannien
| | - Anna E. R. Chamberlain
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA Großbritannien
| | - Jos J. A. G. Kamps
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA Großbritannien
| | - Angelina R. Sekirnik
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA Großbritannien
| | - Stuart J. Conway
- Department of ChemistryChemistry Research LaboratoryUniversity of Oxford Mansfield Road Oxford OX1 3TA Großbritannien
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Pupo G, Vicini AC, Ascough DMH, Ibba F, Christensen KE, Thompson AL, Brown JM, Paton RS, Gouverneur V. Hydrogen Bonding Phase-Transfer Catalysis with Potassium Fluoride: Enantioselective Synthesis of β-Fluoroamines. J Am Chem Soc 2019; 141:2878-2883. [DOI: 10.1021/jacs.8b12568] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gabriele Pupo
- Chemistry Research
Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Anna Chiara Vicini
- Chemistry Research
Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - David M. H. Ascough
- Chemistry Research
Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Francesco Ibba
- Chemistry Research
Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Kirsten E. Christensen
- Chemistry Research
Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Amber L. Thompson
- Chemistry Research
Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - John M. Brown
- Chemistry Research
Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Robert S. Paton
- Chemistry Research
Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Véronique Gouverneur
- Chemistry Research
Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
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Ascough DMH, Duarte F, Paton RS. Stereospecific 1,3-H Transfer of Indenols Proceeds via Persistent Ion-Pairs Anchored by NH···π Interactions. J Am Chem Soc 2018; 140:16740-16748. [PMID: 30338998 DOI: 10.1021/jacs.8b09874] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The base-catalyzed rearrangement of arylindenols is a rare example of a suprafacial [1,3]-hydrogen atom transfer. The mechanism has been proposed to proceed via sequential [1,5]-sigmatropic shifts, which occur in a selective sense and avoid an achiral intermediate. A computational analysis using quantum chemistry casts serious doubt on these suggestions: These pathways have enormous activation barriers, and in constrast to what is observed experimentally, they overwhelmingly favor a racemic product. Instead we propose that a suprafacial [1,3]-prototopic shift occurs in a two-step deprotonation/reprotonation sequence. This mechanism is favored by 15 kcal mol-1 over that previously proposed. Most importantly, this is also consistent with stereospecificity since reprotonation occurs rapidly on the same π-face. We have used explicitly solvated molecular dynamics studies to study the persistence and condensed-phase dynamics of the intermediate ion-pair formed in this reaction. Chirality transfer is the result of a particularly resilient contact ion-pair, held together by electrostatic attraction and a critical NH···π interaction which ensures that this species has an appreciable lifetime even in polar solvents such as DMSO and MeOH.
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Affiliation(s)
- David M H Ascough
- Chemistry Research Laboratory , University of Oxford , 12 Mansfield Road , Oxford OX1 3TA , United Kingdom
| | - Fernanda Duarte
- Chemistry Research Laboratory , University of Oxford , 12 Mansfield Road , Oxford OX1 3TA , United Kingdom
| | - Robert S Paton
- Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , United States.,Chemistry Research Laboratory , University of Oxford , 12 Mansfield Road , Oxford OX1 3TA , United Kingdom
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Pupo G, Ibba F, Ascough DMH, Vicini AC, Ricci P, Christensen KE, Pfeifer L, Morphy JR, Brown JM, Paton RS, Gouverneur V. Asymmetric nucleophilic fluorination under hydrogen bonding phase-transfer catalysis. Science 2018; 360:638-642. [PMID: 29748281 DOI: 10.1126/science.aar7941] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/21/2018] [Indexed: 12/24/2022]
Abstract
Common anionic nucleophiles such as those derived from inorganic salts have not been used for enantioselective catalysis because of their insolubility. Here, we report that merging hydrogen bonding and phase-transfer catalysis provides an effective mode of activation for nucleophiles that are insoluble in organic solvents. This catalytic manifold relies on hydrogen bonding complexation to render nucleophiles soluble and reactive, while simultaneously inducing asymmetry in the ensuing transformation. We demonstrate the concept using a chiral bis-urea catalyst to form a tridentate hydrogen bonding complex with fluoride from its cesium salt, thereby enabling highly efficient enantioselective ring opening of episulfonium ion. This fluorination method is synthetically valuable considering the scarcity of alternative protocols and points the way to wider application of the catalytic approach with diverse anionic nucleophiles.
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Affiliation(s)
- Gabriele Pupo
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Francesco Ibba
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - David M H Ascough
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Anna Chiara Vicini
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Paolo Ricci
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Kirsten E Christensen
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Lukas Pfeifer
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - John Richard Morphy
- Medicinal Chemistry, Eli Lilly and Company Limited, Erl Wood Manor, Sunninghill Road, Windlesham GU20 6PH, UK
| | - John M Brown
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Robert S Paton
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Véronique Gouverneur
- University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK.
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