The xanthine scaffold is known to be the forefather of a class of biological active molecules. Xanthine is a planar framework in which an aryl substituent linked in the 1 or 3 position is driven out of the xanthine plane because of the steric hindrance exerted by the two carbonyls. This work analyses the stereodynamics of some 1-aryl and 1,3-bisaryl-xanthines and describes the steric requirements needed to produce stable heteroaromatic atropisomers or diastereoisomers, with one or two N-Csp2stereogenic axes. The N-C racemization barrier was found to be bigger than 25 kcal/mol. The absolute configurations of the novel atropisomers has been assigned using TD-DFT simulation of ECD spectra.
Conformational Analysis and Absolute Configuration of Axially Chiral 1-Aryl and 1,3-Bisaryl-xanthines / Mancinelli, Michele; Perticarari, Sofia; Prati, Luca; Mazzanti, Andrea. - In: JOURNAL OF ORGANIC CHEMISTRY. - ISSN 0022-3263. - STAMPA. - 82:13(2017), pp. 6874-6885. [10.1021/acs.joc.7b01010]
Conformational Analysis and Absolute Configuration of Axially Chiral 1-Aryl and 1,3-Bisaryl-xanthines
Mancinelli, Michele
;Prati, Luca;Mazzanti, Andrea
2017
Abstract
The xanthine scaffold is known to be the forefather of a class of biological active molecules. Xanthine is a planar framework in which an aryl substituent linked in the 1 or 3 position is driven out of the xanthine plane because of the steric hindrance exerted by the two carbonyls. This work analyses the stereodynamics of some 1-aryl and 1,3-bisaryl-xanthines and describes the steric requirements needed to produce stable heteroaromatic atropisomers or diastereoisomers, with one or two N-Csp2stereogenic axes. The N-C racemization barrier was found to be bigger than 25 kcal/mol. The absolute configurations of the novel atropisomers has been assigned using TD-DFT simulation of ECD spectra.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.