13C GIAO DFT calculation as a tool for configuration prediction of N-O group in saturated heterocyclic N-oxides
Copyright © 2012 John Wiley & Sons, Ltd.
| Veröffentlicht in: | Magnetic resonance in chemistry : MRC. - 1985. - 50(2012), 6 vom: 04. Juni, Seite 415-23 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2012
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| Zugriff auf das übergeordnete Werk: | Magnetic resonance in chemistry : MRC |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Carbon Isotopes Cyclic N-Oxides Piperidines Tropanes isopelletierine 4396-01-4 Cocaine I5Y540LHVR mehr... |
| Zusammenfassung: | Copyright © 2012 John Wiley & Sons, Ltd. Tropane, tropinone, pseudopelletierine and cocaine were oxidized in situ in a nuclear magnetic resonance (NMR) tube providing mixtures of exo/endo N-oxides. Observed (13)C chemical shifts were correlated with values calculated by gauge-including atomic orbitals density functional theory (DFT) OPBE/6-31G* method using DFT B3LYP/6-31G* optimized geometries. The same method of (13)C chemical shift calculation was applied on series of methyl-substituted 1-methylpiperidines and their epimeric N-oxides described in literature. The results show that using this undemanding calculation method enables assignment of configuration of N-O group in N-epimeric saturated heterocyclic N-oxides. The approach enables assigning of the configuration with high degree of certainty even if NMR data of only one isomer are available. An improved method of in situ oxidation of starting amines in an NMR tube is also described |
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| Beschreibung: | Date Completed 28.09.2012 Date Revised 21.11.2013 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1097-458X |
| DOI: | 10.1002/mrc.3810 |