Photochemistry of 1,4-Dihydropyridine Derivatives: Diradical Formation, Delocalization and Trapping as a Route to Novel Tricyclic and Tetracyclic Nitrogen Heterocyclic Ring Systems.
Molecules
; 21(7)2016 Jun 30.
Article
in En
| MEDLINE
| ID: mdl-27376257
ABSTRACT
Irradiation of an acetonitrile solution of 4-aryl-3,5-dibenzoyl-1,4-dihydropyridine derivatives 1a-c and maleimides 2a-c using medium pressure Hg-arc lamp (λ > 290) nm afforded three different cycloadducts 4, 5, 6 in addition to the oxidation products 3. These results indicate that compounds 1a-c undergoes intermolecular cycloaddition reaction through three biradical intermediates and behave photochemically different than those reported previously for the analogous 3,5-diacetyl and 3,5-dicarboxylic acid derivatives. The present work also offers simple access to novel tricyclic and tetracyclic nitrogen heterocyclic ring systems of potential biological and synthetic applications. The structure of the photoproducts was established spectroscopically and by single crystal X-ray crystallography.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Photochemistry
/
Dihydropyridines
/
Photochemical Processes
Language:
En
Journal:
Molecules
Journal subject:
BIOLOGIA
Year:
2016
Document type:
Article
Affiliation country:
Kuwait