The reaction of aldehydes with beta-dicarbonyls and electron-rich aromatics was investigated to generate in a multicomponent fashion crossed adducts of biological relevance. 4-Hydroxycoumarin, triacetic acid lactone, indole, and a selection of aliphatic and aromatic aldehydes representative of various electronic and steric conditions were employed. The reaction showed a surprising dependence on the solvent, with 1:1 chloroform-water giving the best yield of heterodimeric adducts. The mechanistic rationale for the formation of hetero- rather than homodimeric adducts is discussed. (C) 2009 Elsevier Ltd. All rights reserved.
Fe3O4@SiO2-SO3H-DABCO: A novel magnetically retrievable bifunctional catalyst for ecofriendly synthesis of diheteroarylmethanes
sustainable methodologies using green solvents, reusable catalysts and energy saving approaches is the need of time considering the growing stringent environmental regulations. The present study reports the novel three-stepsynthesis of magnetically separable Fe3O4@SiO2-SO3H-DABCO core-shell magnetic nanocomposite catalyst and evaluation of its catalytic efficiency involving the synthesis of structurally diverse
考虑到日益严格的环境法规,开发使用绿色溶剂、可重复使用催化剂和节能方法的可持续方法是需要时间的。本研究报告了磁性可分离 Fe 3 O 4 @SiO 2 -SO 3 H-DABCO 核壳磁性纳米复合催化剂的新型三步合成及其催化效率评估,包括通过一锅反应合成结构多样的二杂芳基甲烷乙醇水溶液中吲哚、芳醛和 4-羟基香豆素的浓度 (50:50 v/v) 在环境条件下。催化剂可以连续循环六次,催化活性或产品产率没有显着变化。生态友好的合成方法提供了几个优点,例如使用绿色溶剂系统、环境反应条件、更短的反应时间、优异的收率和易于使用外部磁铁分离催化剂。