Synthesis and structural analysis of tetra- and pentacyclic lactams derived from regioisomeric tetrahydroisoquinoline diamines

Henri Kivelä, Petri Tähtinen, Olli Martiskainen, Kalevi Pihlaja, L. Lázár, Edina Vigóczki, F. Fülöp

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

By means of the domino ring-closure reactions of 1-(aminomethyl)- and 3-(aminomethyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline with acyclic and aromatic γ- or δ-oxo acids, angularly or linearly condensed tetra- and pentacyclic lactam derivatives were formed with moderate to excellent diastereoselectivities. NMR analysis indicated that the cis diastereomer (a) was the main or the only product in each case, depending on the nature of the starting oxo acid used. The angularly-condensed cis diastereomers were observed to populate two types of conformations in CDCl3 solution, the preferred conformation being determined by the substitution on the lactam ring. These conformers are related by ring inversion of the approximately half-chair-like tetrahydropyridine ring, combined with a pyramidal inversion of its nitrogen atom. For the other combinations of regio- and diastereochemistry, the preferred conformation was not strongly influenced by the lactam substitution within the subset. The linear and angular structural isomers gave fragment ions that were useful for distinguishing between isomers, but with diastereomers the differences were not so clear.

Original languageEnglish
Pages (from-to)62-72
Number of pages11
JournalJournal of Molecular Structure
Volume983
Issue number1-3
DOIs
Publication statusPublished - Nov 1 2010

Fingerprint

Tetrahydroisoquinolines
Lactams
Diamines
Structural analysis
Keto Acids
Conformations
Isomers
Substitution reactions
Nitrogen
Nuclear magnetic resonance
Ions
Derivatives
Atoms

Keywords

  • Diastereoselectivity
  • Domino reactions
  • Lactams
  • Mass spectrometry
  • NMR spectroscopy

ASJC Scopus subject areas

  • Spectroscopy
  • Analytical Chemistry
  • Inorganic Chemistry
  • Organic Chemistry

Cite this

Synthesis and structural analysis of tetra- and pentacyclic lactams derived from regioisomeric tetrahydroisoquinoline diamines. / Kivelä, Henri; Tähtinen, Petri; Martiskainen, Olli; Pihlaja, Kalevi; Lázár, L.; Vigóczki, Edina; Fülöp, F.

In: Journal of Molecular Structure, Vol. 983, No. 1-3, 01.11.2010, p. 62-72.

Research output: Contribution to journalArticle

Kivelä, Henri ; Tähtinen, Petri ; Martiskainen, Olli ; Pihlaja, Kalevi ; Lázár, L. ; Vigóczki, Edina ; Fülöp, F. / Synthesis and structural analysis of tetra- and pentacyclic lactams derived from regioisomeric tetrahydroisoquinoline diamines. In: Journal of Molecular Structure. 2010 ; Vol. 983, No. 1-3. pp. 62-72.
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