1
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Urner LM, Lee GY, Treacy JW, Turlik A, Khan SI, Houk KN, Jung ME. Intramolecular N-H⋅⋅⋅F Hydrogen Bonding Interaction in a Series of 4-Anilino-5-Fluoroquinazolines: Experimental and Theoretical Characterization of Electronic and Conformational Effects. Chemistry 2022; 28:e202103135. [PMID: 34767667 PMCID: PMC9482468 DOI: 10.1002/chem.202103135] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Indexed: 01/12/2023]
Abstract
The 4-anilino-6,7-ethylenedioxy-5-fluoroquinazoline scaffold is presented as a novel model system for the characterization of the weak NH⋅⋅⋅F hydrogen bonding (HB) interaction. In this scaffold, the aniline NH proton is forced into close proximity with the nearby fluorine (dH,F ∼2.0 Å, ∠∼138°), and a through-space interaction is observed by NMR spectroscopy with couplings (1h JNH,F ) of 19±1 Hz. A combination of experimental (NMR spectroscopy and X-ray crystallography) and theoretical methods (DFT calculations) were used for the characterization of this weak interaction. In particular, the effects of conformational rigidity and steric compression on coupling were investigated. This scaffold was used for the direct comparison of fluoride with methoxy as HB acceptors, and the susceptibility of the NH⋅⋅⋅F interaction to changes in electron distribution and resonance was probed by preparing a series of molecules with different electron-donating or -withdrawing groups in the positions para to the NH and F. The results support the idea that fluorine can act as a weak HB acceptor, and the HB strength can be modulated through additive and linear electronic substituent effects.
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Affiliation(s)
- Lorenz M. Urner
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA)
| | - Ga Young Lee
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA)
| | - Joseph W. Treacy
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA)
| | - Aneta Turlik
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA)
| | - Saeed I. Khan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA)
| | - K. N. Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA)
| | - Michael E. Jung
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA)
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2
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Morisue M, Kawanishi M, Ueno I, Nakamura T, Nabeshima T, Imamura K, Nozaki K. Evidence of C-F···H-C Attractive Interaction: Enforced Coplanarity of a Tetrafluorophenylene-Ethynylene-Linked Porphyrin Dimer. J Phys Chem B 2021; 125:9286-9295. [PMID: 34370467 DOI: 10.1021/acs.jpcb.1c04504] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The formation of C-F···H-C "hydrogen bonds" has been a controversial subject because, in principle, fluorine is hardly an acceptor for less acidic protons contrasting to the C-F···H-O and C-F···H-N hydrogen bonds. Nevertheless, the interaction is emerging as a powerful implement for confining the torsional rotation in the design of fully coplanar π-conjugated polymers. Heretofore, no evidence of the C-F···H-C interaction has been observed in solutions. We herein disclose comprehensive evidence that the C-F···H-C interaction produces an attractive force. A 19F-1H heteronuclear Overhauser effect experiment elucidated the close proximity of the F and H atoms in the doubly edge-facing C-F···H-C interactions of a meso-tetrafluorophenylene-ethynylene-conjugated porphyrin dimer (1). Extensive electronic and photophysical property investigations confirmed that all the aromatic units were torsionally restricted by the C-F···H-C interactions. Moreover, the enforced coplanarity invoked a markedly high π-staking propensity. Thus, we have firmly established the formation of a C-F···H-C interaction that produces a hydrogen-bond-like attractive force in solution.
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Affiliation(s)
- Mitsuhiko Morisue
- Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Miho Kawanishi
- Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Ikuya Ueno
- Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Takashi Nakamura
- Faculty of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan
| | - Tatsuya Nabeshima
- Faculty of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan
| | - Kouki Imamura
- Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
| | - Koichi Nozaki
- Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
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3
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Min J, Wang C, Wang L. A new method for detecting intramolecular H-bonds of aromatic amides based on the de-shielding effect of carbonyl groups on β-protons. Phys Chem Chem Phys 2021; 23:13284-13291. [PMID: 34095931 DOI: 10.1039/d1cp01089a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aromatic amide foldamers with highly predictable conformations possess potential for application in the fields of stereoselective recognition, charge transport and catalysis, whose conformations are commonly limited by the intramolecular hydrogen bonding between amide groups and hydrogen-bonding receptors. Herein, on the basis of the de-shielding effect of carbonyl groups on β-protons, we develop a new method for detecting intramolecular hydrogen bonds of aromatic amide compounds. The solvent-related changes in the βH chemical shifts (Δ(δβH)) and NH chemical shifts (Δ(δNH)) of three kinds of amide compounds, which are frequently used as building blocks of aromatic amide foldamers, were recorded in chloroform, nitromethane, acetonitrile and DMSO. The Δ(δβH) method is found to be highly suitable for studying methoxy-benzamides and fluoro-benzamides in chloroform and DMSO. It is worth noting that a reference compound is not required for applying the Δ(δβH) method, which is an advantage over the Δ(δNH) method. In addition, we extend the Δ(δNH) method from methoxy-benzamides to pyridine-carboxamides and fluoro-benzamides in chloroform and DMSO, and propose that nitromethane and acetonitrile will be possible alternatives for the Δ(δNH) method if a test compound is not soluble in chloroform.
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Affiliation(s)
- Jing Min
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
| | - Chunyu Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
| | - Liyan Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
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4
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Tiwari S, Arya N, Mishra SK, Suryaprakash N. Competing HB acceptors: an extensive NMR investigations corroborated by single crystal XRD and DFT calculations. RSC Adv 2021; 11:15195-15202. [PMID: 35424030 PMCID: PMC8698242 DOI: 10.1039/d1ra02538d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 04/11/2021] [Indexed: 11/21/2022] Open
Abstract
A series of N-benzoylanthranilamide derivatives have been synthesized with the substitution of competitive HB acceptors and investigated by NMR spectroscopy and single crystal XRD. The interesting rivalry for HB acceptance between [double bond splayed left]C[double bond, length as m-dash]O and X (F or OMe) is observed in the investigated molecules which leads to an unusual increase in the electron density at the site of one of the NH protons, reflecting in the high field resonance in the 1H NMR spectrum. The NMR experimental findings and single crystal XRD are further reinforced by the DFT studies.
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Affiliation(s)
- Surbhi Tiwari
- NMR Research Centre and Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India +91 80 23601550 +91 80 23607344 +91 80 22933300 +91 98 45124802
| | - Neeru Arya
- NMR Research Centre and Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India +91 80 23601550 +91 80 23607344 +91 80 22933300 +91 98 45124802
| | - Sandeep Kumar Mishra
- Department of Physics and NMR Research Centre, Indian Institute of Science Education and Research Pune 411008 India
| | - N Suryaprakash
- NMR Research Centre and Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India +91 80 23601550 +91 80 23607344 +91 80 22933300 +91 98 45124802
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5
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Huang Z, Dong Y, Li Y, Makha M, Li Y. Enhancing Ligand‐Free Fe‐Catalyzed Aminocarbonylation of Alkynes by ZrF
4. ChemCatChem 2019. [DOI: 10.1002/cctc.201900995] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Zijun Huang
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP)Chinese Academy of Sciences Lanzhou 730000 P. R. China
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Yanan Dong
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP)Chinese Academy of Sciences Lanzhou 730000 P. R. China
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Yudong Li
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP)Chinese Academy of Sciences Lanzhou 730000 P. R. China
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Mohamed Makha
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP)Chinese Academy of Sciences Lanzhou 730000 P. R. China
| | - Yuehui Li
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP)Chinese Academy of Sciences Lanzhou 730000 P. R. China
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6
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Patel AK, Mishra SK, Krishnamurthy K, Suryaprakash N. Retention of strong intramolecular hydrogen bonds in high polarity solvents in binaphthalene–benzamide derivatives: extensive NMR studies. RSC Adv 2019; 9:32759-32770. [PMID: 35529738 PMCID: PMC9073135 DOI: 10.1039/c9ra07299c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 10/07/2019] [Indexed: 11/21/2022] Open
Abstract
Advanced multidimensional NMR techniques have been employed to investigate the intramolecular hydrogen bonds (HBs) in a series of N,N′-([1,1′-binaphthalene]-2,2′-diyl)bis(benzamide) derivatives, with the site-specific substitution of different functional groups. The existence of intramolecular HBs and the elimination of any molecular aggregation and possible intermolecular HBs are ascertained by various experimental NMR techniques, including solvent polarity dependent modifications of HB strengths. In the fluorine substituted derivative, direct evidence for the engagement of organic fluorine in HB is obtained by the detection of heteronuclear through-space correlation and the coupling between two NMR active nuclei where the transmission of spin polarization is mediated through HBs (1hJFH). The extent of reduction in the strength of 1hJFH on dilution with high polarity solvents directly provided the qualitative measure of HB strength. The HB, although becoming weakened, does not get nullified even in pure high polarity solvent, which is attributed to the structural constraints. The rate of exchange of a labile hydrogen atom with the deuterium of the solvent permitted the measurement of their half-lives, that are correlated to the relative strengths of HBs. The experimental NMR findings are further validated by XRD and DFT-based theoretical computations, such as, NCI and QTAIM. NMR studies reveal very strong hydrogen bond unbreakable even in high polarity solvents.![]()
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Affiliation(s)
- Arun Kumar Patel
- Solid State and Structural Chemistry Unit and NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- NMR Research Centre
| | | | | | - N. Suryaprakash
- Solid State and Structural Chemistry Unit and NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- NMR Research Centre
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7
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O'Reilly D, Stein RS, Patrascu MB, Jana SK, Kurian J, Moitessier N, Damha MJ. Exploring Atypical Fluorine-Hydrogen Bonds and Their Effects on Nucleoside Conformations. Chemistry 2018; 24:16432-16439. [PMID: 30125398 DOI: 10.1002/chem.201803940] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Daniel O'Reilly
- Department of Chemistry; McGill University; Otto Maass Chemistry Bldg.; 801 Sherbrooke St. West Montreal QC, H3C0B8 Canada
| | - Robin S. Stein
- Department of Chemistry; McGill University; Otto Maass Chemistry Bldg.; 801 Sherbrooke St. West Montreal QC, H3C0B8 Canada
| | - Mihai Burai Patrascu
- Department of Chemistry; McGill University; Otto Maass Chemistry Bldg.; 801 Sherbrooke St. West Montreal QC, H3C0B8 Canada
| | - Sunit Kumar Jana
- Department of Chemistry; McGill University; Otto Maass Chemistry Bldg.; 801 Sherbrooke St. West Montreal QC, H3C0B8 Canada
| | - Jerry Kurian
- Department of Chemistry; McGill University; Otto Maass Chemistry Bldg.; 801 Sherbrooke St. West Montreal QC, H3C0B8 Canada
| | - Nicolas Moitessier
- Department of Chemistry; McGill University; Otto Maass Chemistry Bldg.; 801 Sherbrooke St. West Montreal QC, H3C0B8 Canada
| | - Masad J. Damha
- Department of Chemistry; McGill University; Otto Maass Chemistry Bldg.; 801 Sherbrooke St. West Montreal QC, H3C0B8 Canada
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8
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Hebeisen P, Weiss U, Alker A, Kuhn B, Müller K, Wang F, Surya Prakash GK. Molecular Structure and Crystal Packing of Monofluoromethoxyarenes. European J Org Chem 2018. [DOI: 10.1002/ejoc.201701758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Paul Hebeisen
- Pharmaceutical Research & Early Development; Roche Innovation Center Basel; F. Hoffmann-La Roche AG; Grenzacherstrasse 124 4070 Basel Switzerland
| | - Urs Weiss
- Pharmaceutical Research & Early Development; Roche Innovation Center Basel; F. Hoffmann-La Roche AG; Grenzacherstrasse 124 4070 Basel Switzerland
| | - André Alker
- Pharmaceutical Research & Early Development; Roche Innovation Center Basel; F. Hoffmann-La Roche AG; Grenzacherstrasse 124 4070 Basel Switzerland
| | - Bernd Kuhn
- Pharmaceutical Research & Early Development; Roche Innovation Center Basel; F. Hoffmann-La Roche AG; Grenzacherstrasse 124 4070 Basel Switzerland
| | - Klaus Müller
- Laboratorium für Organische Chemie; ETH Zürich; Vladimir-Prelog-Weg 3 8093 Zürich Switzerland
| | - Fang Wang
- Loker Hydrocarbon Research Institute; Department of Chemistry; University of Southern California; 1661 Los Angeles CA 90089- USA
| | - G. K. Surya Prakash
- Loker Hydrocarbon Research Institute; Department of Chemistry; University of Southern California; 1661 Los Angeles CA 90089- USA
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9
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Ravindra M, Wilson MR, Tong N, O'Connor C, Karim M, Polin L, Wallace-Povirk A, White K, Kushner J, Hou Z, Matherly LH, Gangjee A. Fluorine-Substituted Pyrrolo[2,3- d]Pyrimidine Analogues with Tumor Targeting via Cellular Uptake by Folate Receptor α and the Proton-Coupled Folate Transporter and Inhibition of de Novo Purine Nucleotide Biosynthesis. J Med Chem 2018; 61:4228-4248. [PMID: 29701475 DOI: 10.1021/acs.jmedchem.8b00408] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Novel fluorinated 2-amino-4-oxo-6-substituted pyrrolo[2,3- d]pyrimidine analogues 7-12 were synthesized and tested for selective cellular uptake by folate receptors (FRs) α and β or the proton-coupled folate transporter (PCFT) and for antitumor efficacy. Compounds 8, 9, 11, and 12 showed increased in vitro antiproliferative activities (∼11-fold) over the nonfluorinated analogues 2, 3, 5, and 6 toward engineered Chinese hamster ovary and HeLa cells expressing FRs or PCFT. Compounds 8, 9, 11, and 12 also inhibited proliferation of IGROV1 and A2780 epithelial ovarian cancer cells; in IGROV1 cells with knockdown of FRα, 9, 11, and 12 showed sustained inhibition associated with uptake by PCFT. All compounds inhibited glycinamide ribonucleotide formyltransferase, a key enzyme in the de novo purine biosynthesis pathway. Molecular modeling studies validated in vitro cell-based results. NMR evidence supports the presence of an intramolecular fluorine-hydrogen bond. Potent in vivo efficacy of 11 was established with IGROV1 xenografts in severe compromised immunodeficient mice.
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Affiliation(s)
- Manasa Ravindra
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States
| | - Mike R Wilson
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Nian Tong
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States
| | - Carrie O'Connor
- Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Mohammad Karim
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States
| | - Lisa Polin
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Adrianne Wallace-Povirk
- Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Kathryn White
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Juiwanna Kushner
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Zhanjun Hou
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Larry H Matherly
- Molecular Therapeutics Program , Barbara Ann Karmanos Cancer Institute , 421 East Canfield Street , Detroit , Michigan 48201 , United States.,Department of Oncology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States.,Department of Pharmacology , Wayne State University School of Medicine , Detroit , Michigan 48201 , United States
| | - Aleem Gangjee
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences , Duquesne University , 600 Forbes Avenue , Pittsburgh , Pennsylvania 15282 , United States
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10
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Dhanishta P, Sai Siva Kumar P, Mishra SK, Suryaprakash N. Intramolecular hydrogen bond directed stable conformations of benzoyl phenyl oxalamides: unambiguous evidence from extensive NMR studies and DFT-based computations. RSC Adv 2018; 8:11230-11240. [PMID: 35541562 PMCID: PMC9079047 DOI: 10.1039/c8ra00357b] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/09/2018] [Indexed: 12/02/2022] Open
Abstract
A number of benzoyl phenyl oxalamide derivatives have been synthesized and characterized by the extensive utility of one- and two-dimensional NMR experimental techniques. The manifestation of intramolecular hydrogen bonds in all of the synthesized molecules, convincingly established using NMR studies, governs the stable conformations of the molecules. In the fluorine substituted molecules, the coupling between two NMR active nuclei mediated through hydrogen bonds has been detected. The measured chemical shift difference of an NH proton has been employed to calculate the energy of the HBs. NMR analysis revealed the electrostatic nature of the hydrogen bonds in all of the molecules. The NMR experimental findings have been validated using Density Functional Theory (DFT)-based Non Covalent Interactions (NCIs) and Quantum Theory of Atoms In Molecules (QTAIM) computations.
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Affiliation(s)
- P Dhanishta
- NMR Research Centre, Indian Institute of Science Bangalore 560 012 India +91-80-23601550 +91-80-23607344 +91-80-22933300 +91-9845124802
- Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560 012 India
| | | | - Sandeep Kumar Mishra
- NMR Research Centre, Indian Institute of Science Bangalore 560 012 India +91-80-23601550 +91-80-23607344 +91-80-22933300 +91-9845124802
- Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560 012 India
| | - N Suryaprakash
- NMR Research Centre, Indian Institute of Science Bangalore 560 012 India +91-80-23601550 +91-80-23607344 +91-80-22933300 +91-9845124802
- Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560 012 India
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11
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Dhanishta P, Mishra SK, Suryaprakash N. Intramolecular HB Interactions Evidenced in Dibenzoyl Oxalamide Derivatives: NMR, QTAIM, and NCI Studies. J Phys Chem A 2017; 122:199-208. [DOI: 10.1021/acs.jpca.7b10598] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. Dhanishta
- NMR Research Centre, Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Sandeep Kumar Mishra
- NMR Research Centre, Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - N. Suryaprakash
- NMR Research Centre, Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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12
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Fluorine NMR spectroscopy and computational calculations for assessing intramolecular hydrogen bond involving fluorine and for characterizing the dynamic of a fluorinated molecule. J Fluor Chem 2017. [DOI: 10.1016/j.jfluchem.2017.07.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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13
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Mishra SK, Suryaprakash N. Intramolecular Hydrogen Bonding Involving Organic Fluorine: NMR Investigations Corroborated by DFT-Based Theoretical Calculations. Molecules 2017; 22:E423. [PMID: 28272370 PMCID: PMC6155419 DOI: 10.3390/molecules22030423] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/02/2017] [Indexed: 01/24/2023] Open
Abstract
The combined utility of many one and two dimensional NMR methodologies and DFT-based theoretical calculations have been exploited to detect the intramolecular hydrogen bond (HB) in number of different organic fluorine-containing derivatives of molecules, viz. benzanilides, hydrazides, imides, benzamides, and diphenyloxamides. The existence of two and three centered hydrogen bonds has been convincingly established in the investigated molecules. The NMR spectral parameters, viz., coupling mediated through hydrogen bond, one-bond NH scalar couplings, physical parameter dependent variation of chemical shifts of NH protons have paved the way for understanding the presence of hydrogen bond involving organic fluorine in all the investigated molecules. The experimental NMR findings are further corroborated by DFT-based theoretical calculations including NCI, QTAIM, MD simulations and NBO analysis. The monitoring of H/D exchange with NMR spectroscopy established the effect of intramolecular HB and the influence of electronegativity of various substituents on the chemical kinetics in the number of organic building blocks. The utility of DQ-SQ technique in determining the information about HB in various fluorine substituted molecules has been convincingly established.
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Affiliation(s)
- Sandeep Kumar Mishra
- NMR Research Centre, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India.
| | - N Suryaprakash
- NMR Research Centre, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India.
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14
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Graton J, Compain G, Besseau F, Bogdan E, Watts JM, Mtashobya L, Wang Z, Weymouth-Wilson A, Galland N, Le Questel JY, Linclau B. Influence of Alcohol β-Fluorination on Hydrogen-Bond Acidity of Conformationally Flexible Substrates. Chemistry 2016; 23:2811-2819. [DOI: 10.1002/chem.201604940] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Jerome 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
| | - Guillaume Compain
- Chemistry; University of Southampton; Highfield Southampton SO17 1BJ UK
| | - Francois 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
| | - 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
| | - Joseph M. Watts
- Chemistry; University of Southampton; Highfield Southampton SO17 1BJ UK
| | - Lewis Mtashobya
- Chemistry; University of Southampton; Highfield Southampton SO17 1BJ UK
| | - Zhong Wang
- Chemistry; University of Southampton; Highfield Southampton SO17 1BJ UK
| | - Alex Weymouth-Wilson
- Dextra Laboratories Ltd; The Science and Technology Centre; Earley Gate, Whiteknights Road Reading RG6 6BZ UK
| | - 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
| | - 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
- Chemistry; University of Southampton; Highfield Southampton SO17 1BJ UK
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15
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Sen I, Kara H, Azizoglu A. Substituent effects on hydrogen bonding of aromatic amide-carboxylate. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2016; 167:50-58. [PMID: 27239947 DOI: 10.1016/j.saa.2016.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 04/27/2016] [Accepted: 05/09/2016] [Indexed: 06/05/2023]
Abstract
N-(p-benzoyl)-anthranilic acid (BAA) derivatives have been synthesized with different substituents (X: Br, Cl, OCH3, CH3), and their crystal structures have been analyzed in order to understand the variations in their molecular geometries with respect to the substituents by using (1)H NMR, (13)C NMR, IR and X-ray single-crystal diffraction. The carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in a centrosymmetric R2(2)(8) ring motifs for BAA-Br and BAA-Cl. However, no carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in BAA-OCH3 and BAA-CH3. The asymmetric unit consists of two crystallographically independent molecules in BAA-OCH3. DFT computations show that the interaction energies between monomer and dimer are in the range of 0.5-3.8kcal/mol with the B3LYP/6-31+G*, B3LYP/6-31++G*, B3LYP/6-31++G**, and B3LYP/AUG-cc-pVDZ levels of theory. The presence of different hydrogen bond patterns is also governed by the substrate. For monomeric compounds studied herein, theoretical calculations lead to two low-energy conformers; trans (a) and cis (b). Former one is more stable than latter by about 4kcal/mol.
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Affiliation(s)
- Ibrahim Sen
- Department of Chemistry, Faculty of Arts and Sciences, University of Balikesir, TR 10145 Balikesir, Turkey
| | - Hulya Kara
- Department of Physics, University of Mugla Sitki Kocman, TR48000 Mugla, Turkey; Department of Physics, Faculty of Arts and Sciences, University of Balikesir, TR 10145 Balikesir, Turkey
| | - Akın Azizoglu
- Department of Chemistry, Faculty of Arts and Sciences, University of Balikesir, TR 10145 Balikesir, Turkey; Havran Vocational School, University of Balikesir, TR 10560 Havran, Balikesir, Turkey.
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16
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Dalvit C, Vulpetti A. Weak Intermolecular Hydrogen Bonds with Fluorine: Detection and Implications for Enzymatic/Chemical Reactions, Chemical Properties, and Ligand/Protein Fluorine NMR Screening. Chemistry 2016; 22:7592-601. [DOI: 10.1002/chem.201600446] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Indexed: 01/05/2023]
Affiliation(s)
- Claudio Dalvit
- Faculty of Science University of Neuchâtel 2000 Neuchâtel Switzerland
- Sanofi, LG-CR/SDI/SBB 94403 Vitry-sur-Seine France
| | - Anna Vulpetti
- Novartis Institutes for Biomedical Research, Global Discovery Chemistry, CADD 4002 Basel Switzerland
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17
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Mishra SK, Suryaprakash N. Intramolecular hydrogen bonds involving organic fluorine in the derivatives of hydrazides: an NMR investigation substantiated by DFT based theoretical calculations. Phys Chem Chem Phys 2016; 17:15226-35. [PMID: 25993543 DOI: 10.1039/c5cp01505g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The rare examples of intramolecular hydrogen bonds (HB) of the type the N-H∙∙∙F-C, detected in a low polarity solvent in the derivatives of hydrazides, by utilizing one and two-dimensional solution state multinuclear NMR techniques, are reported. The observation of through-space couplings, such as, (1h)JFH, and (1h)JFN, provides direct evidence for the existence of intra-molecular HB. Solvent induced perturbations and the variable temperature NMR experiments unambiguously establish the presence of intramolecular HB. The existence of multiple conformers in some of the investigated molecules is also revealed by two dimensional HOESY and (15)N-(1)H HSQC experiments. The (1)H DOSY experimental results discard any possibility of self or cross dimerization of the molecules. The derived NMR experimental results are further substantiated by Density Function Theory (DFT) based Non Covalent Interaction (NCI), and Quantum Theory of Atom in Molecule (QTAIM) calculations. The NCI calculations served as a very sensitive tool for detection of non-covalent interactions and also confirm the presence of bifurcated HBs.
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Affiliation(s)
- Sandeep Kumar Mishra
- NMR Research Centre, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560012, India.
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18
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Hegde G, Rajkumar YA, Mei GS, Mahmood S, Mandal UK, Sudhakar AA. Photoisomerization behavior of photochromic amide-based azobenzene dyes exhibiting H-bonding effect: Synthesis and characterization. KOREAN J CHEM ENG 2016. [DOI: 10.1007/s11814-015-0259-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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19
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Shugrue CR, DeFrancisco JR, Metrano AJ, Brink BD, Nomoto RS, Linton BR. Detection of weak hydrogen bonding to fluoro and nitro groups in solution using H/D exchange. Org Biomol Chem 2016; 14:2223-7. [PMID: 26782121 DOI: 10.1039/c5ob02360b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogen/deuterium (H/D) exchange can be a sensitive technique for measuring the strength of hydrogen bonding to neutral organic nitro and fluoro groups. The slower rates of reaction in comparison to suitable controls suggest that hydrogen bonding is present, albeit rather weak.
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Affiliation(s)
- C R Shugrue
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA.
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20
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Mocilac P, Osman IA, Gallagher JF. Short C–H⋯F interactions involving the 2,5-difluorobenzene group: understanding the role of fluorine in aggregation and complex C–F/C–H disorder in a 2 × 6 isomer grid. CrystEngComm 2016. [DOI: 10.1039/c6ce00795c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Li W, Wu X, Zhao Z, Qin A, Hu R, Tang BZ. Catalyst-Free, Atom-Economic, Multicomponent Polymerizations of Aromatic Diynes, Elemental Sulfur, and Aliphatic Diamines toward Luminescent Polythioamides. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b02193] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Weizhang Li
- State
Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Xiuying Wu
- State
Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Zujin Zhao
- State
Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Anjun Qin
- State
Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Rongrong Hu
- State
Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Ben Zhong Tang
- State
Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
- Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong
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22
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Mishra SK, Suryaprakash N. Organic fluorine involved intramolecular hydrogen bonds in the derivatives of imides: NMR evidence corroborated by DFT based theoretical calculations. RSC Adv 2015. [DOI: 10.1039/c5ra19537c] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The rare occurrence of intramolecular hydrogen bonds (HBs) of the type N–H⋯F–C is detected in the derivatives of imides in a low polarity solvent by using multi-dimensional and multinuclear NMR experiments.
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Affiliation(s)
- Sandeep Kumar Mishra
- NMR Research Centre
- Solid State and Structural Chemistry Unit
- Indian Institute of Science
- Bangalore-560012
- India
| | - N. Suryaprakash
- NMR Research Centre
- Solid State and Structural Chemistry Unit
- Indian Institute of Science
- Bangalore-560012
- India
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23
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Wu FY, Hsu SM, Cheng H, Hsu LH, Lin HC. The effect of fluorine on supramolecular hydrogelation of 4-fluorobenzyl-capped diphenylalanine. NEW J CHEM 2015. [DOI: 10.1039/c5nj00786k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Due to the replacement of only one hydrogen atom by fluorine, 4-fluorobenzyl-diphenylalanine molecules self-assemble to form a transparent hydrogel.
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Affiliation(s)
- Fang-Yi Wu
- Department of Materials Science and Engineering
- National Chiao Tung University
- Hsinchu
- Republic of China
| | - Shu-Min Hsu
- Department of Materials Science and Engineering
- National Chiao Tung University
- Hsinchu
- Republic of China
| | - Hsun Cheng
- Department of Materials Science and Engineering
- National Chiao Tung University
- Hsinchu
- Republic of China
| | - Ling-Huang Hsu
- Department of Materials Science and Engineering
- National Chiao Tung University
- Hsinchu
- Republic of China
| | - Hsin-Chieh Lin
- Department of Materials Science and Engineering
- National Chiao Tung University
- Hsinchu
- Republic of China
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24
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Lakshmipriya A, Rama Chaudhari S, Shahi A, Arunan E, Suryaprakash N. Three centered hydrogen bonds of the type CO⋯H(N)⋯X–C in diphenyloxamide derivatives involving halogens and a rotating CF3 group: NMR, QTAIM, NCI and NBO studies. Phys Chem Chem Phys 2015; 17:7528-36. [DOI: 10.1039/c4cp05917d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The existence of three centered CO⋯H(N)⋯X–C hydrogen bonds (H-bonds) involving organic fluorine and other halogens in diphenyloxamide derivatives has been explored by NMR spectroscopy and quantum theoretical studies.
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Affiliation(s)
- A. Lakshmipriya
- NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- Solid State and Structural Chemistry Unit
| | - Sachin Rama Chaudhari
- NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- Solid State and Structural Chemistry Unit
| | - Abhishek Shahi
- Inorganic and Physical Chemistry Department
- Indian Institute of Science
- Bangalore 560012
- India
| | - E. Arunan
- Inorganic and Physical Chemistry Department
- Indian Institute of Science
- Bangalore 560012
- India
| | - N. Suryaprakash
- NMR Research Centre
- Indian Institute of Science
- Bangalore 560012
- India
- Solid State and Structural Chemistry Unit
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25
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Synthesis of β-amino-α-trifluoromethyl-α-amino acids exhibiting intramolecular interaction of CF3 with NHβ. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.10.107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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26
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Giuffredi GT, Gouverneur V, Bernet B. Intramolecular OH⋅⋅⋅FC Hydrogen Bonding in Fluorinated Carbohydrates: CHF is a Better Hydrogen Bond Acceptor than CF2. Angew Chem Int Ed Engl 2013; 52:10524-8. [DOI: 10.1002/anie.201303766] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/11/2013] [Indexed: 11/08/2022]
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27
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Intramolecular OH⋅⋅⋅FC Hydrogen Bonding in Fluorinated Carbohydrates: CHF is a Better Hydrogen Bond Acceptor than CF2. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201303766] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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28
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Chaudhari SR, Mogurampelly S, Suryaprakash N. Engagement of CF3 Group in N–H···F–C Hydrogen Bond in the Solution State: NMR Spectroscopy and MD Simulation Studies. J Phys Chem B 2013; 117:1123-9. [DOI: 10.1021/jp310798d] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sachin Rama Chaudhari
- NMR
Research Centre, ‡Solid State and Structural Chemistry Unit, and §Department of Physics, Indian Institute of Science, Bangalore
560012, India
| | - Santosh Mogurampelly
- NMR
Research Centre, ‡Solid State and Structural Chemistry Unit, and §Department of Physics, Indian Institute of Science, Bangalore
560012, India
| | - N. Suryaprakash
- NMR
Research Centre, ‡Solid State and Structural Chemistry Unit, and §Department of Physics, Indian Institute of Science, Bangalore
560012, India
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29
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Ohba S, Gomi N, Ohgiya T, Shibuya K. Three derivatives of 4-fluoro-5-sulfonylisoquinoline. Acta Crystallogr C 2012; 68:o427-30. [DOI: 10.1107/s0108270112039388] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 09/15/2012] [Indexed: 11/10/2022] Open
Abstract
In 4-fluoroisoquinoline-5-sulfonyl chloride, C9H5ClFNO2S, (I), one of the two sulfonyl O atoms lies approximately on the isoquinoline plane as a result of minimizing the steric repulsion between the chlorosulfonyl group and the neighbouring F atom. In (S)-(−)-4-fluoro-N-(1-hydroxypropan-2-yl)isoquinoline-5-sulfonamide, C12H13FN2O3S, (II), there are two crystallographically independent molecules (Z′ = 2). The molecular conformations of these two molecules differ in that the amine group of one forms an intramolecular bifurcated hydrogen bond with the F and OH groups, whilst the other forms only a single intramolecular N—H...F hydrogen bond. The N—H...F hydrogen bonds correspond to weak coupling between the N(H) and19F nuclei, observed in the1H NMR solution-state spectra. In (S)-(−)-4-[(4-fluoroisoquinolin-5-yl)sulfonyl]-3-methyl-1,4-diazepan-1-ium chloride, C15H19FN3O2S+·Cl−, (III), the isoquinoline plane is slightly deformed, suggestive of a steric effect induced by the bulky substituent on the sulfonyl group.
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30
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N-H…X (X = F, Cl, Br, and I) hydrogen bonding in aromatic amide derivatives in crystal structures. Sci China Chem 2012. [DOI: 10.1007/s11426-012-4716-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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31
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Mocilac P, Donnelly K, Gallagher JF. Structural systematics and conformational analyses of a 3 × 3 isomer grid of fluoro-N-(pyridyl)benzamides: physicochemical correlations, polymorphism and isomorphous relationships. ACTA CRYSTALLOGRAPHICA SECTION B: STRUCTURAL SCIENCE 2012; 68:189-203. [DOI: 10.1107/s0108768112006799] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 02/15/2012] [Indexed: 11/10/2022]
Abstract
An isomer grid of nine fluoro-N-(pyridyl)benzamides (Fxx) (x = para-/meta-/ortho-) has been examined to correlate structural relationships between the experimental crystal structure and ab initio calculations, based on the effect of fluorine (Fx) and pyridine N-atom (x) substitution patterns on molecular conformation. Eight isomers form N—H...N hydrogen bonds, and only one (Fom) aggregates via intermolecular N—H...O=C interactions exclusively. The Fpm and Fom isomers both crystallize as two polymorphs with Fpm_O (N—H...O=C chains, P-syn
) and Fpm_N (N—H...N chains, P-anti
) both in P21/n (Z′ = 1) differing by their meta-N atom locations (P-syn
, P-anti
; Npyridine referenced to N—H), whereas the disordered Fom_O is mostly P-syn
(Z′ = 6) compared with Fom_F (P-anti
) (Z′ = 1). In the Fxo triad twisted dimers form cyclic R
2
2(8) rings via N—H...N interactions. Computational modelling and conformational preferences of the isomer grid demonstrate that the solid-state conformations generally conform with the most stable calculated conformations except for the Fxm triad, while calculations of the Fox triad predict the intramolecular N—H...F interaction established by spectroscopic and crystallographic data. Comparisons of Fxx with related isomer grids reveal a high degree of similarity in solid-state aggregation and physicochemical properties, while correlation of the melting point behaviour indicates the significance of the substituent position on melting point behaviour rather than the nature of the substituent.
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32
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Divya Kumari, Hebbar S, Suryaprakash N. Intra-molecular hydrogen bonding with organic fluorine in the solution state: Deriving evidence by a two dimensional NMR experiment. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2011.12.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Dalvit C, Vulpetti A. Intermolecular and intramolecular hydrogen bonds involving fluorine atoms: implications for recognition, selectivity, and chemical properties. ChemMedChem 2012; 7:262-72. [PMID: 22262517 DOI: 10.1002/cmdc.201100483] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 12/02/2011] [Indexed: 11/06/2022]
Abstract
A correlation between 19F NMR isotropic chemical shift and close intermolecular F⋅⋅⋅H-X contacts (with X=N or O) has been identified upon analysis of the X-ray crystal structures of fluorinated molecules listed in the Cambridge Structural Database (CSD). An optimal F⋅⋅⋅X distance involving primary and shielded secondary fluorine atoms in hydrogen-bond formation along with a correlation between F⋅⋅⋅H distance and F⋅⋅⋅H-X angle were also derived from the analysis. The hydrogen bonds involving fluorine are relevant, not only for the recognition mechanism and stabilization of a preferred conformation, but also for improvement in the permeability of the molecules, as shown with examples taken from a proprietary database. Results of an analysis of the small number of fluorine-containing natural products listed in the Protein Data Bank (PDB) appear to strengthen the derived correlation between 19F NMR isotropic chemical shift and interactions involving fluorine (also known as the "rule of shielding") and provides a hypothesis for the recognition mechanism and catalytic activity of specific enzymes. Novel chemical scaffolds, based on the rule of shielding, have been designed for recognizing distinct structural motifs present in proteins. It is envisaged that this approach could find useful applications in drug design for the efficient optimization of chemical fragments or promising compounds by increasing potency and selectivity against the desired biomolecular target.
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Affiliation(s)
- Claudio Dalvit
- Department of Chemistry, University of Neuchâtel, Avenue de Bellevaux 51, 2000 Neuchâtel, Swizerland.
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34
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Schneider HJ. Hydrogen bonds with fluorine. Studies in solution, in gas phase and by computations, conflicting conclusions from crystallographic analyses. Chem Sci 2012. [DOI: 10.1039/c2sc00764a] [Citation(s) in RCA: 196] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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Giuffredi GT, Bernet B, Gouverneur V. De Novo Synthesis of Racemic 4-Deoxy-4,4-difluoro- and 2,4-Dideoxy-2,4,4-trifluorohexosides. European J Org Chem 2011. [DOI: 10.1002/ejoc.201100565] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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