Author(s):
Albuquerque, Hélio ; Santos, Clementina M.M. ; Cavaleiro, José ; Silva, Artur
Date: 2015
Persistent ID: http://hdl.handle.net/10198/12559
Origin: Biblioteca Digital da UPB
Project/scholarship:
info:eu-repo/grantAgreement/FCT/COMPETE/PEst-C/QUI/UI0062/2013/PT;
info:eu-repo/grantAgreement/FCT/SFRH/SFRH/BD/86277/2012/PT;
Subject(s): Cycloaddition; Diels-Alder reaction; Cyclization; Click chemistry; Oxygen heterocycles; Nitrogen heterocycles
Description
Xanthone-1,2,3-triazole dyads have been synthesized by two different approaches, both starting from novel (E)-2-(4-arylbut-1-en-3-yn-1-yl)chromones, prepared through a base-catalyzed aldol reaction of 2-methylchromone and arylpropargyl aldehydes. In the first method, the xanthone moiety is built by Diels-Alder reaction of the referred unsaturated chromones with N-methylmaleimide under microwave irradiation, followed by oxidation of the obtained adducts with DDQ, whereas the 1,2,3-triazole ring results from the cycloaddition reaction of the acetylene moiety with sodium azide. The second strategy first involves the cycloaddition reaction with sodium azide to provide the 1,2,3-triazole ring, followed by methylation of the triazole NH group prior to Diels-Alder reaction with N-methylmaleimide. The last step in this synthesis of novel xanthone-1,2,3-triazole dyads entails oxidation of the cycloadducts with DDQ.