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Synthesis of 2-{2-[5(4)-aryl-2H-[1,2,3]-triazol-4(5)-yl]vinyl}chromen-4-ones
Albuquerque, Hélio; Santos, Clementina M.M.; Silva, Artur; Cavaleiro, José A.S.Chromones are a family of oxygen-containing heterocyclic compounds that have been shown particular relevant biological activity. In what concerns to 2-methylchromones, their reactivity is well-known and allowed to exploit many different kinds of chemical reactions. The acidic character of the 2-methyl group, due to the low electron density at C-2 caused by carbonyl group enable this class of compounds to underg...
Synthesis of (E)-2-(4-Arylbut-1-en-3-ynyl)-4H-chromen-4-ones
Albuquerque, Hélio; Santos, Clementina M.M.; Silva, Artur; Cavaleiro, José A.S.Chromones are a well-known class of naturally occurring oxygen-containing heterocyclic compounds; many of them playing important biological functions in nature.[IJ Although 2- methylchromones are one of the scarcest classes of natural chromones, their synthesis and reactivity is well studied. They can participate in several chemical transformations such as oxidation, thiation, hydrogenation, photolysis, cycload...
Synthesis of (E)-2-(4-Arylbut-1-en-3-ynyl)-4H-chromen-4-ones
Albuquerque, Hélio; Santos, Clementina M.M.; Silva, Artur; Cavaleiro, José A.S.Chromones are a well-known class of naturally occurring oxygencontaining heterocyclic compounds; many of them playing important biological functions in nature [1]. Although 2-methylchromones are one of the scarcest classes of natural chromones, their synthesis and reactivity is well studied. They can participate in several chemical transformations such as oxidation, thiation, hydrogenation, photolysis, cycloadd...
Synthesis of 2-{2-[5(4)-aryl-2H-[1,2,3]-triazol-4(5)-yl]vinyl}chromen-4-ones
Albuquerque, Hélio; Santos, Clementina M.M.; Silva, Artur; Cavaleiro, José A.S.Chromones are a family of oxygen-containing heterocyclic compounds that have been shown particular relevant biological activity. In what concerns to 2-methylchromones, their reactivity is well-known and allowed to exploit many different kinds of chemical reactions. The acidic character of the 2-methyl group, due to the low electron density at C-2 caused by carbonyl group enable this class of compounds to underg...
Synthesis of new 1,8-dihydroxy-9h-xanthen-9-ones
Leal, Stephanie B.; Seca, Ana M. L.; Pinto, Diana C. G. A.; Silva, Artur M. S.; Cavaleiro, José A. S.XXVth European Colloquium on Heterocyclic Chemistry, Reading, UK, 13 – 17 Agosto de 2012. ; Xanthones have a rather restricted occurrence among higher plants, being found almost exclusively in Guttiferae and Gentianaceae. Xanthones are sometimes found as polyhydroxylated derivatives, exhibiting valuable biological activities [1], but more often bearing a variety of substituents. Xanthones are well known for th...
Synthesis and antioxidant activity of new xanthone-type compounds
Leal, Stephanie B.; Pinto, Diana C. G. A.; Seca, Ana M. L.; Silva, Artur M. S.; Cavaleiro, José A. S.3rd Portuguese Meeting on Medicinal Chemistry and 1st Portuguese-Spanish-Brazilian Meeting on Medicinal Chemistry, Aveiro, 28-30 Novembro 2012. ; Owing to our continuing interest in the synthesis of novel oxygen heterocycles we have recently developed a unique synthetic procedure towards the synthesis of new xanthenodiones (2)[5] and extend the work to their aromatization into xanthones (3). Our aim was also t...
New xanthenodione: synthesis and antioxidant activity evaluation
Leal, Stephanie B.; Pinto, Diana C. G. A.; Seca, Ana M. L.; Silva, Artur M. S.; Cavaleiro, José A. S.6th Spanish-Portuguese-Japanese Organic Chemistry Symposium, Lisboa, de 18 a 20 de Julho de 2012 (Poster Communication). ; Due to the continuing interest of the research group in the synthesis of novel oxygen heterocycles we have recently developed a unique synthetic route towards new xanthenodiones 5 (scheme 1).[6] The application of this methodology in the cyclization of chromone derivatives 4b,c bearing met...
Tetrahydroquinazoline-substituted chromones from Diels–Alder reaction of (E)-2-...
Patoilo, Diana; Silva, Artur; Pinto, Diana; Santos, Clementina M.M.; Tomé, Augusto; Cavaleiro, JoséThe Diels-Alder reaction of (E)-2-styrylchromones with a pyrimidine ortho-quinodimethane is reported for the first time. These cycloaddition reactions afford mixtures of two regioisomeric tetrahydroquinazoline-substituted chromones in moderate to excellent global yields. Irrespectively of the substituents on the 2-styrylchromones, the 2-(7-aryl-4-methoxy-2-methyl-5,6,7,8-tetrahydroquinazolin-6-yl)chromone deriv...
New syntheses of novel arylxanthones
Rocha, Dejnisa; Esteves, Cátia; Pinto, Diana; Santos, Clementina M.M.; Brito, Cristela; Silva, Artur; Cavaleiro, JoséXanthones represent an outstanding class of oxyg~1_1ated heterocycles widespread in nature, commonly distributed in several higher plant families, such as Gentianaceae, Guttiferae and Polygalaceae and in a few families of fungi and lichens [1]. Both natural and synthetic derivatives often endowed with interesting pharmacological properties (e.g. anti-inflammatory, antitumour and antioxidant activities [1,2]. Na...
Synthesis of novel 2-Butadienylchromone derivatives
Albuquerque, Hélio; Santos, Clementina M.M.; Esteves, Cátia; Silva, Artur; Cavaleiro, JoséChromones are a group of naturally occurring compounds with a benzoannelated ypyrone ring. A large number of chromone derivatives have been isolated from natural sources and a wide range of biological properties have been attribute to them, such as antifungal, anti-allergenic, antiviral, antitubulin, anti-hypertensive, anticancer and antioxidant activities.1 11 Studies with 2-styrylchromones demonstrated that t...
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