1
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O'Hagan D. The Emergence and Properties of Selectively Fluorinated 'Janus' Cyclohexanes. CHEM REC 2023; 23:e202300027. [PMID: 37016509 DOI: 10.1002/tcr.202300027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/14/2023] [Indexed: 04/06/2023]
Abstract
This account describes the evolution of a research programme that started by linking fluoromethylene (-CHF-) groups along aliphatic chains and then progressing to alicyclic rings with contiguous fluorine atoms. Different stereoisomers of aliphatic chains tend to adopt low polarity conformations. In order to force polar conformations, the programme began to address ring systems and in particular cyclohexanes, to restrain conformational freedom and co-aligned C-F bonds. The flagship molecule, all-cis-1,2,3,4,5,6-hexafluorocyclohexane 7, emerged to be the most polar aliphatic compound recorded. The polarity arises because there are three co-aligned triaxial C-F bonds and the six fluorines occupy one face of the ring. Conversely the electropositive hydrogens occupy the other face. These have been termed Janus face cyclohexanes after the Roman god with two faces. The review outlines progress by our group and others in preparing derivatives of the parent cyclohexane 7, in order to explore properties and potential applications of these Janus cyclohexanes.
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Affiliation(s)
- David O'Hagan
- University of St Andrews, St. Andrews, United Kingdom
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2
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Ali HA, Ismail MA, Fouda AEAS, Ghaith EA. A fruitful century for the scalable synthesis and reactions of biphenyl derivatives: applications and biological aspects. RSC Adv 2023; 13:18262-18305. [PMID: 37333795 PMCID: PMC10274569 DOI: 10.1039/d3ra03531j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 06/10/2023] [Indexed: 06/20/2023] Open
Abstract
This review provides recent developments in the current status and latest synthetic methodologies of biphenyl derivatives. Furthermore, this review investigates detailed discussions of several metalated chemical reactions related to biphenyl scaffolds such as Wurtz-Fittig, Ullmann, Bennett-Turner, Negishi, Kumada, Stille, Suzuki-Miyaura, Friedel-Crafts, cyanation, amination, and various electrophilic substitution reactions supported by their mechanistic pathways. Furthermore, the preconditions required for the existence of axial chirality in biaryl compounds are discussed. Furthermore, atropisomerism as a type of axial chirality in biphenyl molecules is discussed. Additionally, this review covers a wide range of biological and medicinal applications of the synthesized compounds involving patented approaches in the last decade corresponding to investigating the crucial role of the biphenyl structures in APIs.
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Affiliation(s)
- Hajar A Ali
- Chemistry Department, Faculty of Science, Mansoura University 35516 Mansoura Egypt
| | - Mohamed A Ismail
- Chemistry Department, Faculty of Science, Mansoura University 35516 Mansoura Egypt
| | - Abd El-Aziz S Fouda
- Chemistry Department, Faculty of Science, Mansoura University 35516 Mansoura Egypt
| | - Eslam A Ghaith
- Chemistry Department, Faculty of Science, Mansoura University 35516 Mansoura Egypt
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3
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Wang Y, Lee W, Chen YC, Zhou Y, Plise E, Migliozzi M, Crawford JJ. Turning the Other Cheek: Influence of the cis-Tetrafluorocyclohexyl Motif on Physicochemical and Metabolic Properties. ACS Med Chem Lett 2022; 13:1517-1523. [PMID: 36105337 PMCID: PMC9465827 DOI: 10.1021/acsmedchemlett.2c00312] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/04/2022] [Indexed: 11/28/2022] Open
Abstract
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The targeted introduction of substituents in order to
tailor a
molecule’s pharmacologic, physicochemical, and metabolic properties
has long been of interest to medicinal chemists. The all-cis tetrafluorocyclohexyl motif—dubbed Janus face, due to its
electrostatically polarized cyclohexyl ring—represents one
such example where chemists might incorporate a metabolically stable,
polar, lipocompatible motif. To better understand its potential utility,
we have synthesized three series of matched molecular pairs (MMPs)
where each MMP differs only in the cyclohexane unit, i.e., with a
tetrafluorocyclohexyl or a standard cyclohexyl motif. With the introduction
of the facially polarized all-cis tetrafluorocyclohexyl
ring, the resulting compounds have significantly modified physicochemical
properties (e.g., kinetic solubility, lipophilicity and permeability)
and metabolic stabilities. These results further speak to the promise
of this substituent as a tactic to improve the drug-like properties
of molecules.
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Affiliation(s)
- Yong Wang
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Wendy Lee
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Yi-Chen Chen
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Yuhui Zhou
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Emile Plise
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Madyson Migliozzi
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - James J. Crawford
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
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4
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Clark JL, Neyyappadath RM, Yu C, Slawin AMZ, Cordes DB, O'Hagan D. Janus All-Cis 2,3,4,5,6-Pentafluorocyclohexyl Building Blocks Applied to Medicinal Chemistry and Bioactives Discovery Chemistry. Chemistry 2021; 27:16000-16005. [PMID: 34486192 PMCID: PMC9292521 DOI: 10.1002/chem.202102819] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Indexed: 12/24/2022]
Abstract
Monoalkylated derivatives of the unusually polar all‐cis 2,3,4,5,6‐ pentafluorocyclohexyl (Janus face) motif are prepared starting from an aryl hydrogenation of 2,3,4,5,6‐ pentafluorophenylacetate methyl ester 15. The method used Zeng's Rh(CAAC) carbene catalyst 4 in the hydrogenation following the protocol developed by Glorius. The resultant Janus pentafluorocyclohexylacetate methyl ester 16 was converted to the corresponding alcohol 18, aldehyde 13, bromide 29 and azide 14 through functional group manipulations, and some of these building blocks were used in Ugi‐multicomponent and Cu‐catalysed click reactions. NBoc protected pentafluoroarylphenylalanine methyl ester 35 was also subject to an aryl hydrogenation, and then deprotection to generate the Janus face β‐pentafluorocyclohexyl‐alanine amino acid 15, which was incorporated into representative members of an emerging class of candidate antiviral compounds. Log P measurements demonstrate that the all‐cis 2,3,4,5,6‐pentafluorocyclohexyl ring system is more polar than a phenyl ring. In overview the paper introduces new building blocks containing this Janus ring and demonstrates their progression to molecules typically used in bioactives discovery programmes.
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Affiliation(s)
- Joshua L Clark
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | | | - Cihang Yu
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Alexandra M Z Slawin
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - David B Cordes
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - David O'Hagan
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
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5
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Mondal R, Agbaria M, Nairoukh Z. Fluorinated Rings: Conformation and Application. Chemistry 2021; 27:7193-7213. [PMID: 33512034 DOI: 10.1002/chem.202005425] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Indexed: 12/16/2022]
Abstract
The introduction of fluorine atoms into molecules and materials across many fields of academic and industrial research is now commonplace, owing to their unique properties. A particularly interesting feature is the impact of fluorine substitution on the relative orientation of a C-F bond when incorporated into organic molecules. In this Review, we will be discussing the conformational behavior of fluorinated aliphatic carbo- and heterocyclic systems. The conformational preference of each system is associated with various interactions introduced by fluorine substitution such as charge-dipole, dipole-dipole, and hyperconjugative interactions. The contribution of each interaction on the stabilization of the fluorinated alicyclic system, which manifests itself in low conformations, will be discussed in detail. The novelty of this feature will be demonstrated by presenting the most recent applications.
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Affiliation(s)
- Rajarshi Mondal
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Israel
| | - Mohamed Agbaria
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Israel
| | - Zackaria Nairoukh
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Israel
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6
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Effect of Fluoroalkyl-Substituent in Bistolane-Based Photoluminescent Liquid Crystals on Their Physical Behavior. CRYSTALS 2021. [DOI: 10.3390/cryst11040450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Photoluminescent liquid crystals (PLLCs) have attracted significant attention owing to their broad applicability in thermosensing and PL switching. Extensive efforts have been made to develop bistolane-based PLLCs containing flexible units at both molecular terminals, and it has been revealed that their PL behavior can switch with the phase transition between the crystalline and LC phases. Although slight modulation of the flexible unit structure dramatically alters the LC and PL behaviors, few studies into the modification of the flexible units have been conducted. With the aim of achieving dynamic changes in their physical behaviors, we developed a family of bistolane derivatives containing a simple alkyl or a fluoroalkyl flexible chain and carried out a detailed systematic evaluation of their physical behaviors. Bistolanes containing a simple alkyl chain showed a nematic LC phase, whereas switching the flexible chain in the bistolane to a fluoroalkyl moiety significantly altered the LC phase to generate a smectic phase. The fluoroalkyl-containing bistolanes displayed a stronger deep blue PL than their corresponding non-fluorinated counterparts, even in the crystalline phase, which was attributed to the construction of rigid molecular aggregates through intermolecular F···H and F···F interactions to suppress non-radiative deactivation.
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7
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O'Hagan D. Polar Organofluorine Substituents: Multivicinal Fluorines on Alkyl Chains and Alicyclic Rings. Chemistry 2020; 26:7981-7997. [PMID: 32083392 DOI: 10.1002/chem.202000178] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/20/2020] [Indexed: 12/12/2022]
Abstract
This Review outlines the progression, primarily of our own work, but with important contributions from other labs, on the synthesis and properties of multiple vicinally fluorinated alkyl chains and rings. Chain conformations of individual diastereoisomers with -CHF- at adjacent carbons are influenced by stereoelectronic factors associated with the polar C-F bond and the polarised geminal hydrogens. Generally, the chain will prefer a conformation which acts to minimise overall molecular polarity, and where the C-F bonds orient away from each other. However, when vicinal fluorine atoms are positioned on a ring then conformations are more constrained. The ring will adopt optimal conformations such as a chair in cyclohexane and then C-F bonds can be introduced with a stereochemistry that forces parallel (axial) orientations. In the case of cyclohexane, 1,3-diaxial arrangements of C-F bonds impart considerable polarity to the ring, resulting in an electronegative 'fluorine face' and an electropositive 'hydrogen face'. For all-syn 1,2,3,4,5,6-hexafluorocyclohexane, this arrangement generates an unusually polar aliphatic ring system. Most recently the concept has been extended to the preparation of all-syn 1,2,3-trifluorocyclopropanes, a rigid ring system with fluorine atoms on one face and hydrogens on the other. Lipophilicity Log P values of such compounds indicate that they are significantly more polar than their parent alicyclic hydrocarbons and give some positive indication for a future role of such substituents in medicinal chemistry. Expanding to such a role will require access to improved synthesis methods to these motifs and consequently access to a broader a range of building blocks, however some exciting new methods have emerged recently and these are briefly reviewed.
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Affiliation(s)
- David O'Hagan
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
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8
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Remete AM, Kiss L. Synthesis of Fluorine-Containing Molecular Entities Through Fluoride Ring Opening of Oxiranes and Aziridines. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900981] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Attila Márió Remete
- Institute of Pharmaceutical Chemistry; University of Szeged; Eötvös u. 6 6720 Szeged Hungary
- Interdisciplinary Excellence Centre; Institute of Pharmaceutical Chemistry; University of Szeged; Eötvös u. 6 6720 Szeged Hungary
| | - Loránd Kiss
- Institute of Pharmaceutical Chemistry; University of Szeged; Eötvös u. 6 6720 Szeged Hungary
- Interdisciplinary Excellence Centre; Institute of Pharmaceutical Chemistry; University of Szeged; Eötvös u. 6 6720 Szeged Hungary
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9
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Quiquempoix L, Wang Z, Graton J, Latchem PG, Light M, Le Questel JY, Linclau B. Synthesis of 2,3,4-Trideoxy-2,3,4-trifluoroglucose. J Org Chem 2019; 84:5899-5906. [DOI: 10.1021/acs.joc.9b00310] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Lucas Quiquempoix
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Zhong Wang
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Jérôme Graton
- CEISAM UMR CNRS 6230, Faculté des Sciences et des Techniques, Université de Nantes 2, rue de la Houssinière−BP 92208, 44322 Nantes Cedex 3, France
| | - Peter G. Latchem
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Mark Light
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Jean-Yves Le Questel
- CEISAM UMR CNRS 6230, Faculté des Sciences et des Techniques, Université de Nantes 2, rue de la Houssinière−BP 92208, 44322 Nantes Cedex 3, France
| | - Bruno Linclau
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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10
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Rodil A, Bosisio S, Ayoup MS, Quinn L, Cordes DB, Slawin AMZ, Murphy CD, Michel J, O'Hagan D. Metabolism and hydrophilicity of the polarised 'Janus face' all- cis tetrafluorocyclohexyl ring, a candidate motif for drug discovery. Chem Sci 2018; 9:3023-3028. [PMID: 29732086 PMCID: PMC5916015 DOI: 10.1039/c8sc00299a] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 02/17/2018] [Indexed: 01/07/2023] Open
Abstract
The metabolism and polarity of the all-cis tetra-fluorocyclohexane motif is explored in the context of its potential as a motif for inclusion in drug discovery programmes. Biotransformations of phenyl all-cis tetra-, tri- and di- fluoro cyclohexanes with the human metabolism model organism Cunninghamella elegans illustrates various hydroxylated products, but limited to benzylic hydroxylation for the phenyl all-cis tetrafluorocyclohexyl ring system. Evaluation of the lipophilicities (log P) indicates a significant and progressive increase in polarity with increasing fluorination on the cyclohexane ring system. Molecular dynamics simulations indicate that water associates much more closely with the hydrogen face of these Janus face cyclohexyl rings than the fluorine face owing to enhanced hydrogen bonding interactions with the polarised hydrogens and water.
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Affiliation(s)
- Andrea Rodil
- EaStChem School of Chemistry , University of St Andrews , North Haugh, St Andrews, Fife KY16 9ST , UK .
| | - Stefano Bosisio
- EaStChem School of Chemistry , University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK .
| | - Mohammed Salah Ayoup
- EaStChem School of Chemistry , University of St Andrews , North Haugh, St Andrews, Fife KY16 9ST , UK . .,Department of Chemistry , Faculty of Science , Alexandria University , P.B. 426 Ibrahimia , Egypt
| | - Laura Quinn
- UCD School of Biomolecular and Biomedical Sciences , University College Dublin , Belfield , Dublin , Ireland .
| | - 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 .
| | - Cormac D Murphy
- UCD School of Biomolecular and Biomedical Sciences , University College Dublin , Belfield , Dublin , Ireland .
| | - Julien Michel
- EaStChem School of Chemistry , University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK .
| | - David O'Hagan
- 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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Al-Maharik N, Kirsch P, Slawin AMZ, Cordes DB, O'Hagan D. Fluorinated liquid crystals: evaluation of selectively fluorinated facially polarised cyclohexyl motifs for liquid crystal applications. Org Biomol Chem 2018; 14:9974-9980. [PMID: 27722421 DOI: 10.1039/c6ob01986b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper explores the synthesis of a series of prototype negative dielectric liquid crystalline (LC) compounds which contain fluorinated cyclohexane motifs. The series are analogues and differ only in that they contain between one to four fluorine atoms. The stereochemistry is such that all of the fluorines/C-F bonds are on one face of the cyclohexane ring. This follows from the recent recognition that cyclohexanes with fluorines orientated in one direction, perpendicular to the ring have a strong molecular dipole, a characteristic that might be an advantage in the design of negative dielectric materials. However it is found that the increased polarity, particularly with two or more oriented C-F bonds, leads to higher melting points and poorer solubility in test matrix formulations, relative to hydrocarbon liquid crystals. This arises due to electrostatic intermolecular interactions between the polarised cyclohexyl and aryl rings. The study highlights that in order to take advantage of these polar cyclohexane motifs for liquid crystal design, appropriate scaffolds are required which are free of aromatic rings and contain peripheral solubilising motifs.
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Affiliation(s)
- Nawaf Al-Maharik
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK.
| | - Peer Kirsch
- Merck KGaA, Liquid Crystals R&D Chemistry, Frankfurter Str. 250, D-64293 Darmstadt, Germany.
| | - Alexandra M Z Slawin
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK.
| | - David B Cordes
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK.
| | - David O'Hagan
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK.
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12
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Thomson CJ, Zhang Q, Al-Maharik N, Bühl M, Cordes DB, Slawin AMZ, O’Hagan D. Fluorinated cyclopropanes: synthesis and chemistry of the aryl α,β,β-trifluorocyclopropane motif. Chem Commun (Camb) 2018; 54:8415-8418. [PMID: 29999054 DOI: 10.1039/c8cc04964e] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A general route to aryl α,β,β-trifluorocyclopropanes is reported and aryl oxidation gave the corresponding α,β,β-trifluorocyclopropane carboxylic acid.
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Affiliation(s)
| | - Qingzhi Zhang
- EaStCHEM School of Chemistry
- University of St. Andrews
- St. Andrews
- UK
| | - Nawaf Al-Maharik
- EaStCHEM School of Chemistry
- University of St. Andrews
- St. Andrews
- UK
- Alistiqlal University
| | - Michael Bühl
- EaStCHEM School of Chemistry
- University of St. Andrews
- St. Andrews
- UK
| | - David B. Cordes
- EaStCHEM School of Chemistry
- University of St. Andrews
- St. Andrews
- UK
| | | | - David O’Hagan
- EaStCHEM School of Chemistry
- University of St. Andrews
- St. Andrews
- UK
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13
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Bykova T, Al-Maharik N, Slawin AMZ, O'Hagan D. Fluorinated cyclohexanes: Synthesis of amine building blocks of the all- cis 2,3,5,6-tetrafluorocyclohexylamine motif. Beilstein J Org Chem 2017; 13:728-733. [PMID: 28503208 PMCID: PMC5405691 DOI: 10.3762/bjoc.13.72] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/28/2017] [Indexed: 01/07/2023] Open
Abstract
This paper reports the synthesis of three amine stereoisomers 5a–c of the tetrafluorocyclohexyl ring system, as building blocks for discovery chemistry programmes. The synthesis starts from a Birch reduction of benzonitrile, followed by an in situ methyl iodide quench. The resultant 2,5-cyclohexadiene was progressed via double epoxidations and then hydrofluorination ring opening reactions. The resultant fluorohydrin moieties were then converted to different stereoisomers of the tetrafluorocyclohexyl ring system, and then reductive hydrogenation of the nitrile delivered three amine stereoisomers. It proved necessary to place a methyl group on the cyclohexane ring in order to stabilise the compound against subsequent HF elimination. The two all-cis tetrafluorocyclohexyl isomers 5a and 5b constitute facially polarized cyclohexane rings, with fluorines on the electronegative face and hydrogens on the electropositive face.
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Affiliation(s)
- Tetiana Bykova
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - Nawaf Al-Maharik
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - Alexandra M Z Slawin
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - David O'Hagan
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
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14
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Jones MJ, Callejo R, Slawin AMZ, Bühl M, O'Hagan D. Organofluorine chemistry: Difluoromethylene motifs spaced 1,3 to each other imparts facial polarity to a cyclohexane ring. Beilstein J Org Chem 2017; 12:2823-2827. [PMID: 28144355 PMCID: PMC5238547 DOI: 10.3762/bjoc.12.281] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/30/2016] [Indexed: 11/23/2022] Open
Abstract
2,2-Dimethyl-5-phenyl-1,1,3,3-tetrafluororocyclohexane has been prepared and characterised as an example of a facially polarised cyclohexane containing 1,3 related CF2 groups. The dipolar nature of the ring arises from the axial orientation of two of the C-F bonds pointing in the same direction, and set by the chair conformation of the cyclohexane. This electrostatic profile is revealed experimentally both in the solid-state (X-ray) packing of the rings and by solution (NMR) in different solvents. A computationally derived electrostatic profile of this compound is consistent with a more electronegative and a more electropositive face of the cyclohexane ring. This placing of CF2 groups 1,3 to each other in a cyclohexane ring is introduced as a new design strategy which could be applicable to the preparation of polar hydrophobic cyclohexane motifs.
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Affiliation(s)
- Mathew J Jones
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK
| | - Ricardo Callejo
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK
| | - Alexandra M Z Slawin
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK
| | - Michael Bühl
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK
| | - David O'Hagan
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK
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15
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Bykova T, Al-Maharik N, Slawin AMZ, O'Hagan D. Multicomponent reactions of methyl substituted all-cis tetrafluorocyclohexane aldehydes. Org Biomol Chem 2016; 14:1117-23. [DOI: 10.1039/c5ob02334c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Syntheses of all-cis tetrafluorocyclohexyl aldehydes are demonstrated with a methyl blocking group to allow their use in Ugi multicomponent reactions.
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Affiliation(s)
| | | | | | - David O'Hagan
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
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16
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Fang Z, Al-Maharik N, Slawin AMZ, Bühl M, O'Hagan D. Polar alicyclic rings: synthesis and structure of all cis-1,2,3,4-tetrafluorocyclopentane. Chem Commun (Camb) 2016; 52:5116-9. [DOI: 10.1039/c6cc01348a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
All-cis-1,2,3,4-tetrafluorocyclopentane is synthesised and experiment and theory data reveal a very highly polar aliphatic with Janus like electropositive and electronegative faces.
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Affiliation(s)
- Zeguo Fang
- University of St Andrews
- School of Chemistry and Centre for Biomolecular Sciences
- North Haugh
- St Andrews
- UK
| | - Nawaf Al-Maharik
- University of St Andrews
- School of Chemistry and Centre for Biomolecular Sciences
- North Haugh
- St Andrews
- UK
| | - Alexandra M. Z. Slawin
- University of St Andrews
- School of Chemistry and Centre for Biomolecular Sciences
- North Haugh
- St Andrews
- UK
| | - Michael Bühl
- University of St Andrews
- School of Chemistry and Centre for Biomolecular Sciences
- North Haugh
- St Andrews
- UK
| | - David O'Hagan
- University of St Andrews
- School of Chemistry and Centre for Biomolecular Sciences
- North Haugh
- St Andrews
- UK
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17
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Ayoup MS, Cordes DB, Slawin AMZ, O'Hagan D. Selectively fluorinated cyclohexane building blocks: Derivatives of carbonylated all-cis-3-phenyl-1,2,4,5-tetrafluorocyclohexane. Beilstein J Org Chem 2015; 11:2671-6. [PMID: 26877788 PMCID: PMC4734450 DOI: 10.3762/bjoc.11.287] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 12/09/2015] [Indexed: 11/23/2022] Open
Abstract
Palladium catalysed carbonylation reactions using the meta- and para-iodo derivatives of all-cis-3-phenyl-1,2,4,5-tetrafluorocyclohexane (4) are illustrated as the start point for a variety of functional group interconversions. The resultant benzaldehyde and benzoic acids offer novel building blocks for further derivatisation and facilitate the incorporation of the facially polarised all-cis-1,2,4,5-tetrafluorocyclohexane motif into more advanced molecular scaffolds.
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Affiliation(s)
- Mohammed Salah Ayoup
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK; Department of Chemistry, Faculty of Science, P.B 426 Ibrahimia, Alexandria University, Egypt
| | - David B Cordes
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - Alexandra M Z Slawin
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - David O'Hagan
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
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18
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Synthesis of selectively fluorinated cyclohexanes: The observation of phenonium rearrangements during deoxyfluorination reactions on cyclohexane rings with a vicinal phenyl substituent. J Fluor Chem 2015. [DOI: 10.1016/j.jfluchem.2015.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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19
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Bogdan E, Compain G, Mtashobya L, Le Questel JY, Besseau F, Galland N, Linclau B, Graton J. Influence of Fluorination on the Conformational Properties and Hydrogen-Bond Acidity of Benzyl Alcohol Derivatives. Chemistry 2015; 21:11462-74. [PMID: 26130594 PMCID: PMC4531824 DOI: 10.1002/chem.201501171] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Indexed: 01/10/2023]
Abstract
The effect of fluorination on the conformational and hydrogen-bond (HB)-donating properties of a series of benzyl alcohols has been investigated experimentally by IR spectroscopy and theoretically with quantum chemical methods (ab initio (MP2) and DFT (MPWB1K)). It was found that o-fluorination generally resulted in an increase in the HB acidity of the hydroxyl group, whereas a decrease was observed upon o,o′-difluorination. Computational analysis showed that the conformational landscapes of the title compounds are strongly influenced by the presence of o-fluorine atoms. Intramolecular interaction descriptors based on AIM, NCI and NBO analyses reveal that, in addition to an intramolecular OH⋅⋅⋅F interaction, secondary CH⋅⋅⋅F and/or CH⋅⋅⋅O interactions also occur, contributing to the stabilisation of the various conformations, and influencing the overall HB properties of the alcohol group. The benzyl alcohol HB-donating capacity trends are properly described by an electrostatic potential based descriptor calculated at the MPWB1K/6-31+G(d,p) level of theory, provided solvation effects are taken into account for these flexible HB donors.
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Affiliation(s)
- Elena Bogdan
- CEISAM UMR CNRS 6230, Faculté des Sciences et des Techniques, Université de Nantes 2, rue de la Houssinière, BP 92208, 44322 NANTES Cedex 3 (France), Fax: (+3) 2-51-12-54-02
| | - Guillaume Compain
- Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ (UK), Fax: (+44) 23-8059-6805
| | - Lewis Mtashobya
- Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ (UK), Fax: (+44) 23-8059-6805
| | - Jean-Yves Le Questel
- CEISAM UMR CNRS 6230, Faculté des Sciences et des Techniques, Université de Nantes 2, rue de la Houssinière, BP 92208, 44322 NANTES Cedex 3 (France), Fax: (+3) 2-51-12-54-02
| | - François Besseau
- CEISAM UMR CNRS 6230, Faculté des Sciences et des Techniques, Université de Nantes 2, rue de la Houssinière, BP 92208, 44322 NANTES Cedex 3 (France), Fax: (+3) 2-51-12-54-02
| | - Nicolas Galland
- CEISAM UMR CNRS 6230, Faculté des Sciences et des Techniques, Université de Nantes 2, rue de la Houssinière, BP 92208, 44322 NANTES Cedex 3 (France), Fax: (+3) 2-51-12-54-02
| | - Bruno Linclau
- Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ (UK), Fax: (+44) 23-8059-6805.
| | - Jérôme Graton
- CEISAM UMR CNRS 6230, Faculté des Sciences et des Techniques, Université de Nantes 2, rue de la Houssinière, BP 92208, 44322 NANTES Cedex 3 (France), Fax: (+3) 2-51-12-54-02.
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20
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Ayoup MS, Cordes DB, Slawin AMZ, O'Hagan D. Fluorine containing amino acids: synthesis and peptide coupling of amino acids containing the all-cis tetrafluorocyclohexyl motif. Org Biomol Chem 2015; 13:5621-4. [DOI: 10.1039/c5ob00650c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A synthesis of amino acids carrying the all-cis tetrafluorocyclohexyl ring moiety is demonstrated and protection/deprotection elaborations are illustrated which show that this facially polarised ring motif may be incorporated into peptides.
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Affiliation(s)
| | | | | | - David O'Hagan
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
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21
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Cormanich RA, Keddie NS, Rittner R, O'Hagan D, Bühl M. Particularly strong C–H⋯π interactions between benzene and all-cis 1,2,3,4,5,6-hexafluorocyclohexane. Phys Chem Chem Phys 2015; 17:29475-8. [DOI: 10.1039/c5cp04537a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
According to high-level ab initio results (SCS-MP2/CBS), the interaction energy between all-cis 1,2,3,4,5,6-hexafluorocyclohexane and a benzene molecule is at least −6 kcal mol−1, remarkably large for C–H⋯π interactions between hydrocarbons.
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Affiliation(s)
| | - Neil S. Keddie
- EastChem School of Chemistry
- University of St Andrews
- North Haugh
- Fife
- UK
| | | | - David O'Hagan
- EastChem School of Chemistry
- University of St Andrews
- North Haugh
- Fife
- UK
| | - Michael Bühl
- EastChem School of Chemistry
- University of St Andrews
- North Haugh
- Fife
- UK
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