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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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Silva DR, Zeoly LA, Cormanich RA, Guerra CF, Freitas MP. Evaluation of the Alicyclic Gauche
Effect in 2-Fluorocyclohexanone Analogs: a Combined NMR and DFT Study. European J Org Chem 2020. [DOI: 10.1002/ejoc.201901815] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Daniela Rodrigues Silva
- Departamento de Química; Universidade Federal de Lavras; 37200-900 Lavras - MG Brazil
- Theoretical Chemistry; Department of Chemistry and Pharmaceutical Sciences; AIMMS, Vrije Universiteit Amsterdam; De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - Lucas A. Zeoly
- Chemistry Institute; University of Campinas; 13083- 970 Campinas - SP Brazil
| | | | - Célia Fonseca Guerra
- Theoretical Chemistry; Department of Chemistry and Pharmaceutical Sciences; AIMMS, Vrije Universiteit Amsterdam; De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Leiden Institute of Chemistry; Gorlaeus Laboratories; Leiden University; Einsteinweg 55 2333 CC Leiden The Netherlands
| | - Matheus P. Freitas
- Departamento de Química; Universidade Federal de Lavras; 37200-900 Lavras - MG Brazil
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3
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Sakai T, Sakakibara H, Omoto Y, Tsunekawa M, Hadano Y, Kato S, Mori Y. Synthesis of the GHIJKL Fragment of Gymnocin-B. Org Lett 2019; 21:6864-6868. [PMID: 31436430 DOI: 10.1021/acs.orglett.9b02502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The GHIJKL fragment of gymnocin-B was synthesized using the oxiranyl anion strategy. The first highlight of the synthesis is the bromoketone cyclization reaction on the oxepane ring to construct the fused bisoxepane GH ring. The second key step is the introduction of the trans-4-hydroxy-3-methyloxepane J ring via addition of trimethylaluminum to a conjugated oxonium moiety, followed by diastereoselective epoxidation and regioselective reduction.
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Affiliation(s)
- Takeo Sakai
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Hideaki Sakakibara
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yumi Omoto
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Marina Tsunekawa
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yoshinori Hadano
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Shota Kato
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yuji Mori
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
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Andrade LA, Silla JM, Freitas MP. An anomalous effect of fluorine on the conformational equilibrium of 2-fluorocyclohexane-1,3-dione. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2018.12.055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Martins FA, Silla JM, Freitas MP. Conformational impact of structural modifications in 2-fluorocyclohexanone. Beilstein J Org Chem 2017; 13:1781-1787. [PMID: 28904621 PMCID: PMC5588668 DOI: 10.3762/bjoc.13.172] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/10/2017] [Indexed: 11/23/2022] Open
Abstract
2-Haloketones are building blocks that combine physical, chemical and biological features of materials and bioactive compounds, while organic fluorine plays a fundamental role in the design of performance organic molecules. Since these features are dependent on the three-dimensional chemical structure of a molecule, simple structural modifications can affect its conformational stability and, consequently, the corresponding physicochemical/biological property of interest. In this work, structural changes in 2-fluorocyclohexanone were theoretically studied with the aim at finding intramolecular interactions that induce the conformational equilibrium towards the axial or equatorial conformer. The interactions evaluated were hydrogen bonding, hyperconjugation, electrostatic and steric effects. While the gauche effect, originated from hyperconjugative interactions, does not appear to cause some preferences for the axial conformation of organofluorine heterocycles, more classical effects indeed rule the conformational equilibrium of the compounds. Spectroscopic parameters (NMR chemical shifts and coupling constants), which can be useful to determine the stereochemistry and the interactions operating in the series of 2-fluorocyclohexanone derivatives, were also calculated.
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Affiliation(s)
- Francisco A Martins
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, MG, Brazil
| | - Josué M Silla
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, MG, Brazil
| | - Matheus P Freitas
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, MG, Brazil
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Silva TFB, Andrade LAF, Silla JM, Duarte CJ, Rittner R, Freitas MP. Endocyclic oxygen in 3-fluorodihydro-2H-pyran-4(3H)-one that does not induce the gauche effect. J Phys Chem A 2014; 118:6266-71. [PMID: 25059100 DOI: 10.1021/jp505573x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
2-Fluorocyclohexanone undergoes chair inversion, giving rise to axial and equatorial conformers, with the equatorial form being highly preferred in solution, for example, 87% in chloroform and 93% in methylene chloride. Modifications in the conformational preferences can modify macroscopic properties of 2-fluoro ketones. The introduction of an endocyclic oxygen in 2-fluorocyclohexanone to give 3-fluorodihydro-2H-pyran-4(3H)-one would be expected to create a gauche effect in the axial conformer along with the O-C-C-F moiety, inducing an increase of its population. However, small changes were verified in the conformational populations both in the gas phase and solution because the carbonyl group plays an important role for the hyperconjugation in the equatorial conformer, despite experiencing strong dipolar repulsion with the fluorine atom. These data were obtained theoretically and by NMR spectroscopy, while the nature of the interactions governing these conformational shifts were investigated on the basis of natural bond orbital analysis.
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Affiliation(s)
- Thayná F B Silva
- Department of Chemistry, Federal University of Lavras , P.O. Box 3037, 37200-000 Lavras, Minas Gerais, Brazil
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Rozada TC, Gauze GF, Favaro DC, Rittner R, Basso EA. Infrared and theoretical calculations in 2-halocycloheptanones conformational analysis. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 94:277-287. [PMID: 22534556 DOI: 10.1016/j.saa.2012.03.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/04/2012] [Accepted: 03/09/2012] [Indexed: 05/31/2023]
Abstract
2-Halocycloheptanones (Halo=F, Cl, Br and I) were synthesized and their conformational analysis was performed through infrared spectroscopy data. The corresponding conformers geometries and energies were obtained by theoretical calculations at B3LYP/aug-cc-pVDZ level of theory in the isolated state and in solution. It was observed, by both approaches, that the conformational preferences were very sensitive to the solvent polarity, since its increase led to an increase in the population of the more polar conformer. An analysis of these conformational equilibria showed they suffer also the influence of stereoelectronic effects, like hyperconjugation and steric effects. These results were interpreted using natural bond orbital (NBO) analysis, which indicated that the electronic delocalization to the orbital π*(C=O) is directly involved in the stability increase of conformers I and II. The relative effect of the period of the halogen can also be noted, with changes in the conformational preferences and in the energies involved in the interactions of NBO.
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Affiliation(s)
- Thiago C Rozada
- Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR, Brazil
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Azarakhshi F, Nori-Shargh D, Attar H, Masnabadi N, Yahyaei H, Mousavi SN, Boggs JE. Conformational behaviours of 2-substituted cyclohexanones: a complete basis set, hybrid-DFT study and NBO interpretation. MOLECULAR SIMULATION 2011. [DOI: 10.1080/08927022.2011.590986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Coelho JV, Freitas MP, Ramalho TC, Martins CR, Bitencourt M, Cormanich RA, Tormena CF, Rittner R. The case of infrared carbonyl stretching intensities of 2-bromocyclohexanone: Conformational and intermolecular interaction insights. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.05.097] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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