An experimental and theoretical NMR study of NH-benzimidazoles in solution and in the solid state: proton transfer and tautomerism

This paper reports the (1)H, (13)C and (15)N NMR experimental study of five benzimidazoles in solution and in the solid state ((13)C and (15)N CPMAS NMR) as well as the theoretically calculated (GIAO/DFT) chemical shifts. We have assigned unambiguously the "tautomeric positions" (C3a/C7a,...

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Autores principales: Nieto, Carla I, Cabildo, Pilar, García, M Ángeles, Claramunt, Rosa M, Alkorta, Ibon, Elguero, José
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Beilstein-Institut 2014
Materias:
Full Research Paper
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4142846/
https://www.ncbi.nlm.nih.gov/pubmed/25161719
http://dx.doi.org/10.3762/bjoc.10.168
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author Nieto, Carla I
Cabildo, Pilar
García, M Ángeles
Claramunt, Rosa M
Alkorta, Ibon
Elguero, José
author_facet Nieto, Carla I
Cabildo, Pilar
García, M Ángeles
Claramunt, Rosa M
Alkorta, Ibon
Elguero, José
author_sort Nieto, Carla I
collection PubMed
description This paper reports the (1)H, (13)C and (15)N NMR experimental study of five benzimidazoles in solution and in the solid state ((13)C and (15)N CPMAS NMR) as well as the theoretically calculated (GIAO/DFT) chemical shifts. We have assigned unambiguously the "tautomeric positions" (C3a/C7a, C4/C7 and C5/C6) of NH-benzimidazoles that, in some solvents and in the solid state, appear different (blocked tautomerism). In the case of 1H-benzimidazole itself we have measured the prototropic rate in HMPA-d(18).
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spelling pubmed-41428462014-08-26 An experimental and theoretical NMR study of NH-benzimidazoles in solution and in the solid state: proton transfer and tautomerism Nieto, Carla I Cabildo, Pilar García, M Ángeles Claramunt, Rosa M Alkorta, Ibon Elguero, José Beilstein J Org Chem Full Research Paper This paper reports the (1)H, (13)C and (15)N NMR experimental study of five benzimidazoles in solution and in the solid state ((13)C and (15)N CPMAS NMR) as well as the theoretically calculated (GIAO/DFT) chemical shifts. We have assigned unambiguously the "tautomeric positions" (C3a/C7a, C4/C7 and C5/C6) of NH-benzimidazoles that, in some solvents and in the solid state, appear different (blocked tautomerism). In the case of 1H-benzimidazole itself we have measured the prototropic rate in HMPA-d(18). Beilstein-Institut 2014-07-16 /pmc/articles/PMC4142846/ /pubmed/25161719 http://dx.doi.org/10.3762/bjoc.10.168 Text en Copyright © 2014, Nieto et al. https://creativecommons.org/licenses/by/2.0https://www.beilstein-journals.org/bjoc/termsThis is an Open Access article under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The license is subject to the Beilstein Journal of Organic Chemistry terms and conditions: (https://www.beilstein-journals.org/bjoc/terms)
spellingShingle Full Research Paper
Nieto, Carla I
Cabildo, Pilar
García, M Ángeles
Claramunt, Rosa M
Alkorta, Ibon
Elguero, José
An experimental and theoretical NMR study of NH-benzimidazoles in solution and in the solid state: proton transfer and tautomerism
title An experimental and theoretical NMR study of NH-benzimidazoles in solution and in the solid state: proton transfer and tautomerism
title_full An experimental and theoretical NMR study of NH-benzimidazoles in solution and in the solid state: proton transfer and tautomerism
title_fullStr An experimental and theoretical NMR study of NH-benzimidazoles in solution and in the solid state: proton transfer and tautomerism
title_full_unstemmed An experimental and theoretical NMR study of NH-benzimidazoles in solution and in the solid state: proton transfer and tautomerism
title_short An experimental and theoretical NMR study of NH-benzimidazoles in solution and in the solid state: proton transfer and tautomerism
title_sort experimental and theoretical nmr study of nh-benzimidazoles in solution and in the solid state: proton transfer and tautomerism
topic Full Research Paper
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4142846/
https://www.ncbi.nlm.nih.gov/pubmed/25161719
http://dx.doi.org/10.3762/bjoc.10.168
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