Ag/SiO2 as a recyclable catalyst for the facile green synthesis of 3-methyl-4-(phenyl)methylene-isoxazole-5(4H)-ones
作者:Surya Narayana Maddila、Suresh Maddila、Werner E. van Zyl、Sreekantha B. Jonnalagadda
DOI:10.1007/s11164-015-2167-2
日期:2016.3
An efficient and facile green method for synthesis of 3-methyl-4-(phenyl)methylene-isoxazole-5(4H)-one (4a-m) via room temperature reaction of hydroxylamine, ethylacetoacetate and substituted aromatic aldehydes is designed, using Ag/SiO2 as catalyst with water as solvent. This protocol offers several advantages, such as it being a benign, energy conserving and eco-friendly reaction with products obtained in excellent yields (88–93 %). The reaction requires relatively short reaction times (< 1 h), a simple workup procedure with good atom efficiency and easily recoverable catalyst. The heterogeneous catalyst, Ag/SiO2, was fully characterized and is reusable without loss of activity for up to seven cycles with marginal activity loss.
A facile and environmental-friendly protocol for the synthesis of methyleneisoxazole-5(4H)-ones catalyzed by CeO2/TiO2 under ultrasonic irradiation
作者:Suresh Maddila、Lagudu Devi、Pamerla Muralidhar、Kerru Nagaraju、Sreekantha B. Jonnalagadda
DOI:10.1016/j.inoche.2022.109741
日期:2022.9
mesoporous nature of CeO2/TiO2, which possessed a specific surface area of 110.6 m2.g─1 and an average pore size 83 nm. Then, SEM and TEM ascertained the disordered pores in their morphology. Further, the catalytic activity of the prepared nanocomposite was applied for the synthesis of methyleneisoxazole-5(4H)-one analogue via one-pot and multicomponent reaction of substituted aldehyde, ethyl acetoacetate
通过沉积-沉淀法合成了一种新型高效的纳米复合材料,通过 FE-SEM、SEM-EDX、P-XRD、TEM、TGA 和 BET 分析对其进行了表征。2.5 mol% CeO 2 /TiO 2的 P-XRD 和 N2 吸附研究证实了 CeO 2 / TiO 2的无定形介孔性质,其比表面积为 110.6 m 2 .g ─1,平均孔径为 83 nm。然后,SEM 和 TEM 确定了其形态中的无序孔。 此外,将制备的纳米复合材料的催化活性应用于在超声照射下,在环保的情况下,通过取代醛、乙酰乙酸乙酯和羟胺的一锅多组分反应合成亚甲基异恶唑-5(4H)-one 类似物。 . 处理简单、使用容易获得的起始材料、消除有毒溶剂、环境友好、易于后处理、更清洁的反应曲线、高产品收率 (94–99%) 和短反应时间 (≤10 分钟)、可回收性和可重复使用性是这种方法的几个好处。