A clean and expedient synthesis of spirooxindoles catalyzed by silica–sulfuric acid nanoparticles as an efficient and reusable reagent
作者:Bahareh Sadeghi、Maryam Ghasemi Pirbaluti、Parinaz Farokhi Nezhad、Reza Abbasi Nezhad
DOI:10.1007/s11164-013-1509-1
日期:2015.6
An atom-efficient, one-pot, three-component synthetic method, using silica–sulfuric acid nanoparticles as catalyst, has been developed for preparation of biologically important spirooxindoles. The reaction involves the use of isatin or 5-fluoroisatin, malononitrile, and enolizable systems. A wide range of enolizable systems can be used in this reaction, furnishing excellent yields in a short time. The catalyst is recyclable with reproducible results without any loss of its activity. The morphology of the silica–sulfuric acid nanoparticles was observed by scanning electron microscopy. Some of the compounds were new and their structures were deduced by elemental and spectral analysis (IR, 1H NMR, and 13C NMR). Moreover, column chromatography and recrystallization of the products is not required because the crude products are already highly pure.
一种高效率、单锅、三组分的合成方法已被开发,该方法使用二氧化硅-硫酸纳米颗粒作为催化剂,旨在制备生物重要的螺环氧吲哚。该反应涉及使用异丁酸或5-氟异丁酸、丙二腈和可酯化系统。广泛的可酯化体系可用于此反应,能够在短时间内提供优异的产率。该催化剂可回收,并且结果可重复,无活性损失。通过扫描电子显微镜观察二氧化硅-硫酸纳米颗粒的形态。部分化合物为新化合物,其结构通过元素分析和光谱分析(IR、1H NMR和13C NMR)推断。此外,由于粗产品已经高度纯净,故不需要柱色谱和重结晶。