13C GIAO DFT calculation as a tool for configuration prediction of N-O group in saturated heterocyclic N-oxides
Result description
Tropane, tropinone, pseudopelletierine and cocaine were oxidized in situ in a nuclear magnetic resonance (NMR) tube providing mixtures of exo/endo N-oxides. Observed 13C 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 13C chemical shift calculation was applied on series of methyl-substituted 1-methylpiperidines and their epimeric N-oxides described inliterature. The results show that using this undemanding calculation method enables assignment of configuration of NO group in N-epimeric saturated heterocyclic N-oxides. The approach enables assigning of the configuration with high degree of certaintyeven 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.
Keywords
NMR13C1Hsaturated heterocyclic N-oxideschemical shift calculationsDFT
The result's identifiers
Result code in IS VaVaI
Result on the web
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
13C GIAO DFT calculation as a tool for configuration prediction of N-O group in saturated heterocyclic N-oxides
Original language description
Tropane, tropinone, pseudopelletierine and cocaine were oxidized in situ in a nuclear magnetic resonance (NMR) tube providing mixtures of exo/endo N-oxides. Observed 13C 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 13C chemical shift calculation was applied on series of methyl-substituted 1-methylpiperidines and their epimeric N-oxides described inliterature. The results show that using this undemanding calculation method enables assignment of configuration of NO group in N-epimeric saturated heterocyclic N-oxides. The approach enables assigning of the configuration with high degree of certaintyeven 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.
Czech name
—
Czech description
—
Classification
Type
Jx - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
CC - Organic chemistry
OECD FORD branch
—
Result continuities
Project
Continuities
Z - Vyzkumny zamer (s odkazem do CEZ)
Others
Publication year
2012
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Magnetic Resonance in Chemistry
ISSN
0749-1581
e-ISSN
—
Volume of the periodical
50
Issue of the periodical within the volume
6
Country of publishing house
GB - UNITED KINGDOM
Number of pages
9
Pages from-to
415-423
UT code for WoS article
000304086100002
EID of the result in the Scopus database
—
Basic information
Result type
Jx - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP
CC - Organic chemistry
Year of implementation
2012