Synthesis of New Captodative Alkenes: Alkyl 2-Aroyloxy Acrylates − Structure, and Reactivity in Diels−Alder Cycloadditions
作者:Rafael Herrera、Hugo A. Jiménez-Vázquez、Alberto Modelli、Derek Jones、Björn C. Söderberg、Joaquín Tamariz
DOI:10.1002/1099-0690(200112)2001:24<4657::aid-ejoc4657>3.0.co;2-3
日期:2001.12
the methyl and ethyl esters of 2-aroyloxyacrylic acids, 2 and 3, have been prepared. Their reactivity and selectivity have been evaluated in Diels−Alder cycloadditions with unsymmetrical dienes, which generate the corresponding adducts with high regioselectivity. No significant stereoselectivity was observed in the reaction with cyclopentadiene (9), although Lewis acid catalysis improved the exo/endo
已经制备了新型俘获性烯烃,即 2-芳酰氧基丙烯酸的甲酯和乙酯,2 和 3。它们的反应性和选择性已经在具有不对称二烯的 Diels-Alder 环加成反应中进行了评估,这会产生具有高区域选择性的相应加合物。在与环戊二烯 (9) 的反应中没有观察到显着的立体选择性,尽管路易斯酸催化改善了外/内异构比例。MO 计算支持对这些烯烃的结构和电子光谱研究。FMO 理论解释了用异戊二烯 (7) 观察到的区域选择性,并且在 Diels-Alder 加成中看到的反应性与这些烯烃中相关空位 π* MO 的稳定性相关,这主要是由于吸电子基团。