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 language | English |
|---|---|
| Pages (from-to) | 62-72 |
| Number of pages | 11 |
| Journal | Journal of Molecular Structure |
| Volume | 983 |
| Issue number | 1-3 |
| DOIs | |
| Publication status | Published - Nov 1 2010 |
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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 journal › Article
}
TY - JOUR
T1 - Synthesis and structural analysis of tetra- and pentacyclic lactams derived from regioisomeric tetrahydroisoquinoline diamines
AU - Kivelä, Henri
AU - Tähtinen, Petri
AU - Martiskainen, Olli
AU - Pihlaja, Kalevi
AU - Lázár, L.
AU - Vigóczki, Edina
AU - Fülöp, F.
PY - 2010/11/1
Y1 - 2010/11/1
N2 - 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.
AB - 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.
KW - Diastereoselectivity
KW - Domino reactions
KW - Lactams
KW - Mass spectrometry
KW - NMR spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=77958509758&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77958509758&partnerID=8YFLogxK
U2 - 10.1016/j.molstruc.2010.08.031
DO - 10.1016/j.molstruc.2010.08.031
M3 - Article
AN - SCOPUS:77958509758
VL - 983
SP - 62
EP - 72
JO - Journal of Molecular Structure
JF - Journal of Molecular Structure
SN - 0022-2860
IS - 1-3
ER -