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

被引：46

作者：

Nieto, Carla I. ^{[1
]}

Cabildo, Pilar ^{[1
]}

Angeles Garcia, M. ^{[1
]}

Claramunt, Rosa M. ^{[1
]}

Alkorta, Ibon ^{[2
]}

Elguero, Jose ^{[2
]}

机构：

[1] Fac Ciencias, Dept Quim Organ & Bioorgan, E-28040 Madrid, Spain

[2] CSIC, Inst Quim Med, E-28006 Madrid, Spain

来源：

BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY | 2014年 / 10卷

关键词：

CPMAS; DNMR; GIAO; proton transfer; tautomerism; MULTINUCLEAR MAGNETIC-RESONANCE; MOLECULAR-ORBITAL METHODS; HETEROCYCLIC SERIES; CROSS-POLARIZATION; CHEMICAL-SHIFT; C-13; N-15; SPECTROSCOPY; BENZAZOLES; OMEPRAZOLE;

D O I：

10.3762/bjoc.10.168

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

This paper reports the H-1, C-13 and N-15 NMR experimental study of five benzimidazoles in solution and in the solid state (C-13 and N-15 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).

引用

页码：1620 / 1629

页数：10

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