کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1406521 | 1501831 | 2010 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Synthesis and structural analysis of tetra- and pentacyclic lactams derived from regioisomeric tetrahydroisoquinoline diamines
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
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.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 983, Issues 1â3, 1 November 2010, Pages 62-72
Journal: Journal of Molecular Structure - Volume 983, Issues 1â3, 1 November 2010, Pages 62-72
نویسندگان
Henri Kivelä, Petri Tähtinen, Olli Martiskainen, Kalevi Pihlaja, László Lázár, Edina Vigóczki, Ferenc Fülöp,