Synthesis of substituted flavones and chromones using a Wells-Dawson heteropolyacid as catalyst

In this work, we report the use of bulk and silica-supported Wells-Dawson acid (H2P2W18O62.24H2O) as reusable, heterogeneous catalysts to obtain substituted flavones and chromones for the cyclization of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones. The reaction experiments were performed using tolue...

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Autores principales: Bennardi, Daniel Oscar, Romanelli, Gustavo Pablo, Jios, Jorge Luis, Autino, Juan Carlos, Baronetti, Graciela Teresita, Thomas, Horacio Jorge
Formato: Articulo
Lenguaje:Inglés
Publicado: 2008
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83026
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Sumario:In this work, we report the use of bulk and silica-supported Wells-Dawson acid (H2P2W18O62.24H2O) as reusable, heterogeneous catalysts to obtain substituted flavones and chromones for the cyclization of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones. The reaction experiments were performed using toluene as solvent at reflux and in the absence of solvent, at 110°C. Under these conditions eleven examples were obtained with very good yields (82-91%) and high selectivity. The catalysts were easily recycled and reused without loss of their catalytic activity. The presented synthetic method is a simple, clean and environmentally friendly alternative for synthesizing substituted flavones and chromones.