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Garg A, Haswell A, Hopkinson MN. C-F Bond Insertion: An Emerging Strategy for Constructing Fluorinated Molecules. Chemistry 2024; 30:e202304229. [PMID: 38270496 DOI: 10.1002/chem.202304229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 01/26/2024]
Abstract
C-F Insertion reactions, where an organic fragment formally inserts into a carbon-fluorine bond in a substrate, are highly attractive, yet largely unexplored, methods to prepare valuable fluorinated molecules. The inherent strength of C-F bonds and the resulting need for a large thermodynamic driving force to initiate C-F cleavage often leads to sequestering of the released fluoride in an unreactive by-product. Recently, however, several groups have succeeded in overcoming this challenge, opening up the study of C-F insertion as an efficient and highly atom-economical approach to prepare fluorinated compounds. In this article, the recent breakthroughs are discussed focusing on the key conceptual advances that allowed for both C-F bond cleavage and subsequent incorporation of the released fluoride into the product.
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Affiliation(s)
- Arushi Garg
- School of Natural and Environmental Sciences, Newcastle University, Bedson Building, NE1 7RU, Newcastle Upon Tyne, UK
| | - Alex Haswell
- School of Natural and Environmental Sciences, Newcastle University, Bedson Building, NE1 7RU, Newcastle Upon Tyne, UK
| | - Matthew N Hopkinson
- School of Natural and Environmental Sciences, Newcastle University, Bedson Building, NE1 7RU, Newcastle Upon Tyne, UK
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2
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Kitahara T, Tagami Y, Haga Y, Fustero S, Sugiishi T, Amii H. Alkylation and silylation of α-fluorobenzyl anion intermediates. Org Biomol Chem 2023; 21:9210-9215. [PMID: 37961788 DOI: 10.1039/d3ob01586f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Simple α-fluorobenzyl anions reacted with electrophiles such as non-activated alkyl halides and chlorotrimethylsilane. Upon treatment with LTMP as the base, fluoromethylbenzenes took part in the formation of α-monofluorobenzyl anions without stabilizing o-substituents. Furthermore, the resulting α-silyl fluoromethylbenzenes reacted with electrophiles such as acetophenone and benzaldehyde in the presence of cesium fluoride to form α-fluorobenzylated alcohols.
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Affiliation(s)
- Taku Kitahara
- Division of Molecular Science, Graduate School of Science and Technology, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
| | - Yuta Tagami
- Division of Molecular Science, Graduate School of Science and Technology, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
| | - Yuto Haga
- Division of Molecular Science, Graduate School of Science and Technology, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
| | - Santos Fustero
- Departamento de Química Orgánica, Facultad de Farmacia, Universitat de València, Vicente Andrés Estelles s/n, C.P.: 46100 Burjassot, Valencia, Spain
| | - Tsuyuka Sugiishi
- Division of Molecular Science, Graduate School of Science and Technology, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
| | - Hideki Amii
- Division of Molecular Science, Graduate School of Science and Technology, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
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3
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Bertrand X, Pucheault M, Chabaud L, Paquin JF. Synthesis of Tertiary Fluorides through an Acid-Mediated Deoxyfluorination of Tertiary Alcohols. J Org Chem 2023; 88:14527-14539. [PMID: 37769207 DOI: 10.1021/acs.joc.3c01558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
The combination of methanesulfonic acid and potassium bifluoride is reported for the deoxyfluorination of tertiary alcohols. Under metal-free conditions that use readily available, cheap, and easy-to-handle reagents, a range of tertiary alcohols could be converted into the corresponding fluorides in excellent yields (average yields of 85% for 23 examples). Mechanistic investigation showed that the reaction proceeds at 0 °C, in part, through an elimination/hydrofluorination pathway, but no residual alkenes are observed. The application of these conditions for the fluorination of ether and ester is also demonstrated.
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Affiliation(s)
- Xavier Bertrand
- CCVC, PROTEO, Département de chimie, Université Laval, 1045 Avenue de la médecine, Québec, Québec G1V 0A6, Canada
- Univ. Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, F-33400 Talence, France
| | - Mathieu Pucheault
- Univ. Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, F-33400 Talence, France
| | - Laurent Chabaud
- Univ. Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, F-33400 Talence, France
| | - Jean-François Paquin
- CCVC, PROTEO, Département de chimie, Université Laval, 1045 Avenue de la médecine, Québec, Québec G1V 0A6, Canada
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Nielsen MM, Pedersen CM. Vessel effects in organic chemical reactions; a century-old, overlooked phenomenon. Chem Sci 2022; 13:6181-6196. [PMID: 35733904 PMCID: PMC9159102 DOI: 10.1039/d2sc01125e] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/03/2022] [Indexed: 12/01/2022] Open
Abstract
One of the most intriguing aspects of synthetic chemistry is the interplay of numerous dependent and independent variables en route to achieve a successful, high-yielding chemical transformation. The experienced synthetic chemist will probe many of these variables during reaction development and optimization, which will routinely involve investigation of reaction temperature, solvent, stoichiometry, concentration, time, choice of catalyst, addition sequence or quenching conditions just to name some commonly addressed variables. Remarkably, little attention is typically given to the choice of reaction vessel material as the surface of common laboratory borosilicate glassware is, incorrectly, assumed to be chemically inert. When reviewing the scientific literature, careful consideration of the vessel material is typically only given during the use of well-known glass-etching reagents such as HF, which is typically only handled in HF-resistant, polyfluorinated polymer vessels. However, there are examples of chemical transformations that do not involve such reagents but are still clearly influenced by the choice of reaction vessel material. In the following review, we wish to condense the most significant examples of vessel effects during chemical transformations as well as observations of container-dependent stability of certain molecules. While the primary focus is on synthetic organic chemistry, relevant examples from inorganic chemistry, polymerization reactions, atmospheric chemistry and prebiotic chemistry are also covered.
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Affiliation(s)
- Michael Martin Nielsen
- Department of Chemistry, University of Copenhagen Universitetsparken 5 2100 Copenhagen O Denmark
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Abstract
AbstractThe unique properties of fluorine-containing organic compounds make fluorine substitution attractive for the development of pharmaceuticals and various specialty materials, which have inspired the evolution of diverse C-F bond activation techniques. Although many advances have been made in functionalizations of activated C-F bonds utilizing transition metal complexes, there are fewer approaches available for nonactivated C-F bonds due to the difficulty in oxidative addition of transition metals to the inert C-F bonds. In this regard, using Lewis acid to abstract the fluoride and light/radical initiator to generate the radical intermediate have emerged as powerful tools for activating those inert C-F bonds. Meanwhile, these transition-metal-free processes are greener, economical, and for the pharmaceutical industry, without heavy metal residues. This review provides an overview of recent C-F bond activations and functionalizations under transition-metal-free conditions. The key mechanisms involved are demonstrated and discussed in detail. Finally, a brief discussion on the existing limitations of this field and our perspective are presented.
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Vulpetti A, Dalvit C. Hydrogen Bond Acceptor Propensity of Different Fluorine Atom Types: An Analysis of Experimentally and Computationally Derived Parameters. Chemistry 2021; 27:8764-8773. [PMID: 33949737 DOI: 10.1002/chem.202100301] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Indexed: 12/29/2022]
Abstract
The propensity of organic fluorine acting as a weak hydrogen bond acceptor (HBA) in intermolecular and intramolecular interactions has been the subject of many experimental and theoretical studies often reaching different conclusions. Over the last few years, new and stronger evidences have emerged for the direct involvement of fluorine in weak hydrogen bond (HB) formation. However, not all the fluorine atom types can act as weak HBA. In this work, the differential HBA propensity of various types of fluorine atoms was analyzed with a particular emphasis for the different types of alkyl fluorides. This was carried out by evaluating ab initio computed parameters, experimental 19 F NMR chemical shifts and small molecule crystallographic structures (extracted from the CSD database). According to this analysis, shielded (with reference to the 19 F NMR chemical shift) alkyl mono-fluorinated motifs display the highest HBA propensity in agreement with solution studies. Although much weaker than other well-characterized HB complexes, the fragile HBs formed by these fluorinated motifs have important implications for the chemical-physical and structural properties of the molecules, chemical reactions, and protein-ligand recognition.
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Affiliation(s)
- Anna Vulpetti
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, 4002, Basel, Switzerland
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Houle C, Savoie PR, Davies C, Jardel D, Champagne PA, Bibal B, Paquin J. Thiourea‐Catalyzed C−F Bond Activation: Amination of Benzylic Fluorides. Chemistry 2020; 26:10620-10625. [DOI: 10.1002/chem.202001905] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Camille Houle
- CCVC, PROTEODépartement de chimieUniversité Laval 1045 avenue de la Médecine Québec QC G1V 0A6 Canada
| | - Paul R. Savoie
- CCVC, PROTEODépartement de chimieUniversité Laval 1045 avenue de la Médecine Québec QC G1V 0A6 Canada
| | - Clotilde Davies
- Institut des Sciences MoléculairesUniversité de BordeauxUMR CNRS 5255 351 cours de la Libération 33405 Talence France
| | - Damien Jardel
- Institut des Sciences MoléculairesUniversité de BordeauxUMR CNRS 5255 351 cours de la Libération 33405 Talence France
| | - Pier Alexandre Champagne
- Department of Chemistry and Environmental ScienceNew Jersey Institute of Technology Newark NJ 07102 USA
| | - Brigitte Bibal
- Institut des Sciences MoléculairesUniversité de BordeauxUMR CNRS 5255 351 cours de la Libération 33405 Talence France
| | - Jean‐François Paquin
- CCVC, PROTEODépartement de chimieUniversité Laval 1045 avenue de la Médecine Québec QC G1V 0A6 Canada
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Nielsen MM, Qiao Y, Wang Y, Pedersen CM. Vessel Effect in C-F Bond Activation Prompts Revised Mechanism and Reveals an Autocatalytic Glycosylation. European J Org Chem 2020. [DOI: 10.1002/ejoc.201901755] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Michael M. Nielsen
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Copenhagen Denmark
| | - Yan Qiao
- Institute of Coal Chemistry; Chinese Academy of Sciences; 27 South Taiyuan Road 030001 Taiyuan People's Republic of China
| | - Yingxiong Wang
- Institute of Coal Chemistry; Chinese Academy of Sciences; 27 South Taiyuan Road 030001 Taiyuan People's Republic of China
| | - Christian M. Pedersen
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Copenhagen Denmark
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Pryyma A, Bu YJ, Wai Y, Patrick BO, Perrin DM. Synthesis and Activation of Bench-Stable 3a-Fluoropyrroloindolines as Latent Electrophiles for the Synthesis of C-2-Thiol-Substituted Tryptophans and C-3a-Substituted Pyrroloindolines. Org Lett 2019; 21:8234-8238. [DOI: 10.1021/acs.orglett.9b02972] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alla Pryyma
- Chemistry Department, University of British Columbia, 2016 Main Mall, Vancouver, British Columbia V6T-1Z1, Canada
| | - Yong Jia Bu
- Chemistry Department, University of British Columbia, 2016 Main Mall, Vancouver, British Columbia V6T-1Z1, Canada
| | - Yonnie Wai
- Chemistry Department, University of British Columbia, 2016 Main Mall, Vancouver, British Columbia V6T-1Z1, Canada
| | - Brian O. Patrick
- Chemistry Department, University of British Columbia, 2016 Main Mall, Vancouver, British Columbia V6T-1Z1, Canada
| | - David M. Perrin
- Chemistry Department, University of British Columbia, 2016 Main Mall, Vancouver, British Columbia V6T-1Z1, Canada
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Guo J, Bamford KL, Stephan DW. 9-Borabicyclo[3.3.l]nonane-induced Friedel-Crafts benzylation of arenes with benzyl fluorides. Org Biomol Chem 2019; 17:5258-5261. [PMID: 31107484 DOI: 10.1039/c9ob00912d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Friedel-Crafts benzylation of arenes with benzyl fluorides using 9-borabicyclo[3.3.l]nonane (9-BBN) as a mediator has been developed. This provides a simple and cheap route to the activation of C-F bonds to synthesize 1,1-diarylmethanes in good to excellent yields (up to 98%) under mild conditions. Functional group tolerance and the mechanism are considered.
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Affiliation(s)
- Jing Guo
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
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11
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Abstract
A closer look is given to the successful approaches to the C(sp3)–F activation of benzylic, allylic, propargylic and allenylic fluorides.
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