Vibrational and electronic circular dichroism studies on the axially chiral pyridine-N-oxide

trans-2,6-di-ortho-tolyl-3,4,5-trimethylpyridine-N-oxide

Florina Teodorescu, Simona Nica, Cornelia Uncuta, Emeric Bartha, Petru Ivan Filip, Nicolas Vanthuyne, Christian Roussel, Attila Mándi, László Tóth, T. Kurtán, Jean Valère Naubron, Isabela Costinela Man

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The absolute configuration of the resolved axially chiral pyridine-N-oxide derivative, (±)-trans-2,6-di-ortho-tolyl-3,4,5-trimethylpyridine-N-oxide, has been determined by VCD and ECD analyses supported by TD-DFT calculations carried out at different levels of theory. DFT calculations confirmed that in spite of the two biaryl axes, the compound is conformationally less flexible and the major conformer is stabilized by two weak hydrogen bonds formed between the hydrogen of the methyl group of the tolyl moieties and the nitroxide oxygen. The experimental VCD spectra of this compound and the previously studied (±)-2,6-di-sec-butyl-4-methylpyridine-N-oxide with two stereogenic centers were compared in the frequency range 1200-1300 cm-1. A (+,-,+)/(-,+,-) pattern of bands was observed in both cases. By replacing the sec-butyl moieties with tolyl ones, the VCD peaks shifted toward higher frequencies and the intensities were increased.

Original languageEnglish
Article number59355
Pages (from-to)1043-1049
Number of pages7
JournalTetrahedron Asymmetry
Volume26
Issue number18-19
DOIs
Publication statusPublished - Jun 19 2015

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Dichroism
Discrete Fourier transforms
Pyridine
Oxides
dichroism
pyridines
oxides
electronics
Hydrogen
Hydrogen bonds
Oxygen
Derivatives
frequency ranges
hydrogen bonds
oxygen
hydrogen
configurations
pyridine N-oxide
4-methylpyridine

ASJC Scopus subject areas

  • Organic Chemistry
  • Inorganic Chemistry
  • Physical and Theoretical Chemistry
  • Catalysis

Cite this

Vibrational and electronic circular dichroism studies on the axially chiral pyridine-N-oxide : trans-2,6-di-ortho-tolyl-3,4,5-trimethylpyridine-N-oxide. / Teodorescu, Florina; Nica, Simona; Uncuta, Cornelia; Bartha, Emeric; Filip, Petru Ivan; Vanthuyne, Nicolas; Roussel, Christian; Mándi, Attila; Tóth, László; Kurtán, T.; Naubron, Jean Valère; Man, Isabela Costinela.

In: Tetrahedron Asymmetry, Vol. 26, No. 18-19, 59355, 19.06.2015, p. 1043-1049.

Research output: Contribution to journalArticle

Teodorescu, F, Nica, S, Uncuta, C, Bartha, E, Filip, PI, Vanthuyne, N, Roussel, C, Mándi, A, Tóth, L, Kurtán, T, Naubron, JV & Man, IC 2015, 'Vibrational and electronic circular dichroism studies on the axially chiral pyridine-N-oxide: trans-2,6-di-ortho-tolyl-3,4,5-trimethylpyridine-N-oxide', Tetrahedron Asymmetry, vol. 26, no. 18-19, 59355, pp. 1043-1049. https://doi.org/10.1016/j.tetasy.2015.08.006
Teodorescu, Florina ; Nica, Simona ; Uncuta, Cornelia ; Bartha, Emeric ; Filip, Petru Ivan ; Vanthuyne, Nicolas ; Roussel, Christian ; Mándi, Attila ; Tóth, László ; Kurtán, T. ; Naubron, Jean Valère ; Man, Isabela Costinela. / Vibrational and electronic circular dichroism studies on the axially chiral pyridine-N-oxide : trans-2,6-di-ortho-tolyl-3,4,5-trimethylpyridine-N-oxide. In: Tetrahedron Asymmetry. 2015 ; Vol. 26, No. 18-19. pp. 1043-1049.
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