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A 13C chemical shifts study of iodopyrazoles: experimental results and relativistic and non-relativistic calculations. Struct Chem 2021. [DOI: 10.1007/s11224-021-01755-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Infantes L, Moreno JM, Claramunt RM, Sanz D, Alkorta I, Elguero J. The structure of four thallium tris(1H-pyrazol-1-yl)hydroborates in the solid state by X-ray crystallography and in solution by NMR and DFT-GIAO calculations. Inorganica Chim Acta 2018. [DOI: 10.1016/j.ica.2018.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Claramunt RM, Santa María D, Alkorta I, Elguero J. The Structure ofN-phenyl-pyrazoles and Indazoles: Mononitro, Dinitro, and Trinitro Derivatives. J Heterocycl Chem 2017. [DOI: 10.1002/jhet.3026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Rosa M. Claramunt
- Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias; UNED; Paseo Senda del Rey, 9 28040 Madrid Spain
| | - Dolores Santa María
- Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias; UNED; Paseo Senda del Rey, 9 28040 Madrid Spain
| | - Ibon Alkorta
- Instituto de Química Médica, Centro de Química Orgánica “Manuel Lora-Tamayo”; CSIC; Juan de la Cierva, 3 28006 Madrid Spain
| | - José Elguero
- Instituto de Química Médica, Centro de Química Orgánica “Manuel Lora-Tamayo”; CSIC; Juan de la Cierva, 3 28006 Madrid Spain
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Krivdin LB. Calculation of 15N NMR chemical shifts: Recent advances and perspectives. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 102-103:98-119. [PMID: 29157495 DOI: 10.1016/j.pnmrs.2017.08.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 08/21/2017] [Accepted: 08/21/2017] [Indexed: 06/07/2023]
Abstract
Recent advances in computation of 15N NMR chemical shifts are reviewed, concentrating mainly on practical aspects of computational protocols and accuracy factors. The review includes the discussion of the level of theory, the choice of density functionals and basis sets together with taking into account solvent effects, rovibrational corrections and relativistic effects. Computational aspects of 15N NMR are illustrated for the series of neutral and protonated open-chain nitrogen-containing compounds and nitrogen heterocycles, coordination and intermolecular complexes.
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Affiliation(s)
- Leonid B Krivdin
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033 Irkutsk, Russia.
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Alkorta I, Elguero J, Pérez-Torralba M, López C, Claramunt RM. A theoretical and experimental study of the NMR spectra of 4,5,6,7-tetrafluorobenzazoles with special stress on PCM calculations of chemical shifts. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:353-362. [PMID: 25615404 DOI: 10.1002/mrc.4203] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 12/04/2014] [Indexed: 06/04/2023]
Abstract
The chemical shifts and several (19)F-(19)F, (13)C-(19) F and (1)H-(19)F spin-spin coupling constants (SSCSs) of eight 4,5,6,7-tetraflurobenzazoles (three benzimidazoles, three benzimidazolinones and two indazoles) have been determined. The chemical shifts were discussed using gauge including atomic orbital-density functional theory calculations taking into account solvent effects (polarizable continuum model) and, for the solid state, hydrogen bonds (clusters up to three molecules).
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Affiliation(s)
- Ibon Alkorta
- Instituto de Química Médica, CSIC, Juan de la Cierva 3, E-28006, Madrid, Spain
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Buathongjan C, Beukeaw D, Yotphan S. Iodine-Catalyzed Oxidative Amination of Sodium Sulfinates: A Convenient Approach to the Synthesis of Sulfonamides under Mild Conditions. European J Org Chem 2015. [DOI: 10.1002/ejoc.201403531] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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7
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Abarca B, Ballesteros R, Adam R, Ballesteros-Garrido R, Leroux FR, Colobert F, Alkorta I, Elguero J. A theoretical and experimental study of the racemization process of hexaaza[5]helicenes. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.09.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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An experimental and theoretical study of the structure of Lamotrigine in its neutral and protonated forms: evidence of Lamotrigine enantiomers. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.02.075] [Citation(s) in RCA: 13] [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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9
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Indazoles: a new top seed structure in the search of efficient drugs against Trypanosoma cruzi. Future Med Chem 2013; 5:1843-59. [DOI: 10.4155/fmc.13.144] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
For years, Chagas disease treatment has been limited to only two drugs of highly questionable and controversial use (Nifurtimox® and Benznidazole®). In the search of effective drugs, many efforts have been made, but only a few structures have emerged as actual candidates. Heading into this, the multitarget-directed approach appears as the best choice. In this framework, indazoles were shown to be potent Trypanosoma cruzi growth inhibitors, being able to lead both the formation of reactive oxygen species and the inhibition of trypanothione reductase. Herein, we discuss the main structural factors that rule the anti-T. cruzi properties of indazoles, and how they would be involved in the biological properties as well as in the action mechanisms, attempting to make parallels between the old paradigms and current evidences in order to outline what could be the next steps to follow in regard to the future drug design for Chagas disease treatment.
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Tiekink ERT, Wardell SMSV, Wardell JL. 3,5-Dimethyl-1-(4-nitro-phen-yl)-1H-pyrazole. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o1018. [PMID: 22589891 PMCID: PMC3343982 DOI: 10.1107/s1600536812009579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Accepted: 03/05/2012] [Indexed: 12/04/2022]
Abstract
In the title pyrazole derivative, C11H11N3O2, the benzene ring is twisted [dihedral angle = 31.38 (12)°] with respect to the pyrazole ring (r.m.s. deviation = 0.009 Å). The nitro group is effectively coplanar with the benzene ring to which it is attached [O—N—C—C torsion angle = −6.5 (3)°]. Supramolecular chains along the b axis are formed owing to π–π interactions [3.8653 (2) Å] between translationally related molecules involving both the five- and six-membered rings.
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Pérez Medina C, López C, Claramunt RM, Elguero J. Trifluoro-3-hydroxy-1H-indazolecarboxylic Acids and Esters from Perfluorinated Benzenedicarboxylic Acids. European J Org Chem 2010. [DOI: 10.1002/ejoc.200901102] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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López C, Claramunt RM, Pinilla E, Torres MR, Alkorta I, Elguero J. Molecular complexes between pi-excedent heterocycles (indoles and carbazole) and pi-deficient polynitrobenzenes. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2009; 47:917-924. [PMID: 19650063 DOI: 10.1002/mrc.2483] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Five charge-transfer complexes 1-5 derived from indoles (including a carbazole) and halogenopolynitrobenzenes (ClDNB, FDNB, ClTNB) as well as their individual components have been studied in the solid state by (13)C CPMAS NMR. The stacking effects on the (13)C chemical shifts have been rationalized by means of M05-2X functional and GIAO/B3LYP/6-311 ++G(d,p) calculations. The results, although only semiquantitative, are very promising for studying such structures.
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Affiliation(s)
- Concepción López
- Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, UNED, Senda del Rey 9, E-28040 Madrid, Spain.
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Benchabane Y, Boyer G, Humbel S, Alkorta I, Elguero J. A theoretical and NMR experimental study of N1,N3-di(3-aminoacridin-6-yl)-isophthalamide and N2,N6-di(3-aminoacridin-6-yl)-2,6-dicarboxamide. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2009.03.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Alkorta I, Elguero J. How Aromaticity Affects the Chemical and Physicochemical Properties of Heterocycles: A Computational Approach. TOPICS IN HETEROCYCLIC CHEMISTRY 2008. [DOI: 10.1007/978-3-540-68343-8_4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Affiliation(s)
- Andreas Schmidt
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678 Clausthal‐Zellerfeld, Germany, Fax: +49‐5323‐722858
| | - Ariane Beutler
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678 Clausthal‐Zellerfeld, Germany, Fax: +49‐5323‐722858
| | - Bohdan Snovydovych
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678 Clausthal‐Zellerfeld, Germany, Fax: +49‐5323‐722858
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Angeles García M, Claramunt RM, Elguero J. 13C and 15N NMR chemical shifts of 1-(2',4'-dinitrophenyl) and 1-(2',4',6'-trinitrophenyl) pyrazoles in the solid state and in solution. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:697-700. [PMID: 18383432 DOI: 10.1002/mrc.2219] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The (13)C and (15)N CPMAS NMR spectra of 18 pyrazoles substituted at position 1 by dinitrophenyl and trinitrophenyl (picryl) groups have been recorded. To help in the assignments, some of these compounds were studied in DMSO-d(6) solution. Phenomena such as the conformation of the N-aryl groups and broadening of splittings due to quadrupolar nuclei are discussed.
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Affiliation(s)
- M Angeles García
- Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, UNED, Senda del Rey 9, E-28040 Madrid, Spain
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Blanco F, Alkorta I, Elguero J. Statistical analysis of (13)C and (15)N NMR chemical shifts from GIAO/B3LYP/6-311 + + G** calculated absolute shieldings. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2007; 45:797-800. [PMID: 17661432 DOI: 10.1002/mrc.2053] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The (13)C and (15)N absolute shieldings of 28 compounds have been calculated at the GIAO/B3LYP/6-311 + + G** level to complete a collection of data already published. This has allowed us to devise new equations relating delta and sigma for these nuclei based on 461 points ((13)C) and 70(72) points ((15)N).
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Affiliation(s)
- Fernando Blanco
- Instituto de Química Médica, CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
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Katritzky AR, Akhmedov NG, Doskocz J, Mohapatra PP, Hall CD, Güven A. NMR spectra, GIAO and charge density calculations of five-membered aromatic heterocycles. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2007; 45:532-43. [PMID: 17534885 DOI: 10.1002/mrc.1967] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The B3LYP/6-31+G(d) molecular geometry optimized structures of 17 five-membered heterocycles were employed together with the gauge including atomic orbitals (GIAO) density functional theory (DFT) method at the B3LYP/6-31+G(d,p), B3LYP/6-311++G(d,p) and B3LYP/6-311+G(2d,p) levels of theory for the calculation of proton and carbon chemicals shifts and coupling constants. The method of geometry optimization for pyrrole (1), N-methylpyrrole (2) and thiophene (7) using the larger 6-311++G(d,p) basis sets at the B3LYP/6-31+G(d,p), B3LYP/6-311++G(d,p), B3LYP/6-31+G(2d,p) and B3LYP/cc-pVTZ levels of theory gave little difference between calculated and experimental values of coupling constants. In general, the (1)H and 13C chemical shifts for all compounds are in good agreement with theoretical calculations using the smaller 6-31 basis set. The values of nJHH(n=3, 4, 5) and rmnJ(CH)(n=1, 2, 3, 4) were predicted well using the larger 6-31+G(d,p) and 6-311++G(d,p) basis sets and at the B3LYP/6-31+G(d,p), B3LYP/6-311++G(d,p), B3LYP/6-31+G(2d,2p) levels of theory. The computed atomic charges [Mülliken; Natural Bond Orbital Analysis (NBO); Merz-Kollman (MK); CHELP and CHELPG] for the B3LYP/6-311++G(d,p) geometry optimized structures of 1-17 were used to explore correlations with the experimental proton and carbon chemical shifts.
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Affiliation(s)
- Alan R Katritzky
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA.
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