Polar Diels-Alder Reactions Using Heterocycles as Electrophiles. Influence of Microwave Irradiation
Maria N. Kneeteman
Department of Chemistry, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe, Argentina and National Council of Scientific and Technical Research (CONICET), Argentina
Anna F. López Baena
Department of Chemistry, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe, Argentina
Claudia Della Rosa
Department of Chemistry, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe, Argentina
Pedro M. E. Mancini *
Department of Chemistry, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe, Argentina
*Author to whom correspondence should be addressed.
Abstract
In this work we studied a series of polar Diels-Alder reactions using different heterocycles derivatives acting as electrophiles joint to dienes of different nucleophilicity, analyzing the effect of the microwave irradiation in these processes. We employ the technique in two conditions: benzene as solvent and solvent free reactions. The last one presents the better yield in shorter time of reaction. Using microwave heating the aromatic cycloadducts are clearly predominant. It is possible to demonstrate that the microwave irradiation has a better influence on these cycloaddition reactions respect to those developed in thermal classical conditions.
Keywords: Aromatic heterocycles, electrophiles, microwave irradiation, solvent free, Diels-Alder