Tandem Diels−Alder Aromatization Reactions of Furans under Unconventional Reaction Conditions − Experimental and Theoretical Studies
作者:José M. Fraile、José I. García、María A. Gómez、Antonio de la Hoz、José A. Mayoral、Andrés Moreno、Pilar Prieto、Luis Salvatella、Ester Vázquez
DOI:10.1002/1099-0690(200108)2001:15<2891::aid-ejoc2891>3.0.co;2-m
日期:2001.8
acids are good catalysts for Diels−Alder reactions between furan and acrylonitrile and methyl acrylate at room temperature. When 2,5-dimethylfuran is used as the diene, yields of the Diels−Alder adducts with methyl acrylate are lower, due in part to the appearance of aromatization products. The use of microwave activation results in some cases in good yields of aromatic products and, as such, constitutes
二氧化硅负载的路易斯酸是室温下呋喃与丙烯腈和丙烯酸甲酯之间的 Diels-Alder 反应的良好催化剂。当使用 2,5-二甲基呋喃作为二烯时,Diels-Alder 加合物与丙烯酸甲酯的产率较低,部分原因是芳构化产物的出现。在某些情况下,微波活化的使用导致芳族产品的高产率,因此,构成了多取代芳族化合物的良好合成途径。对反应机理和催化剂对产物分布作用的计算研究表明,“硬”路易斯酸,如铝衍生物,使加合物的开环更容易,得到芳香族产物。