pyrroles were synthesized via three-component condensation reaction of benzoin derivatives, 1,3-dicarbonyl compounds, and ammoniumacetate using acidic Al2O3 as an efficient and reusable heterogeneous catalyst in refluxing ethanol in high yields. Also, acidic alumina was catalyzed 1,4-dihydro-tetraarylpyrazines by the condensation reaction of benzoins and ammoniumacetate in refluxing ethanol in high
摘要利用酸性Al 2 O 3作为高效可重复使用的多相催化剂,通过苯偶姻衍生物,1,3-二羰基化合物和乙酸铵的三组分缩合反应,合成了一些新的2,3,4,5-四取代的吡咯。高产。同样,通过苯甲酸酯和乙酸铵在回流的乙醇中的缩合反应,可以高产率地催化酸性氧化铝催化1,4-二氢-四芳基吡嗪。当用于连续反应运行时,氧化铝显示出几乎相同的效率。 图形概要酸性氧化铝用作非均相酸性催化剂,用于在回流的乙醇中合成四取代的吡咯。催化剂可以循环使用几次。
Improved Catalyst-Free Synthesis of Pyrrole Derivatives in Aqueous Media
作者:Fatemeh Tamaddon、Farideh Amirpoor
DOI:10.1055/s-0033-1339294
日期:——
An improved catalyst-free, three-component reaction of ammonium acetate, 1,3-dicarbonyl compounds, and aromatic a-hydroxycarbonyl compounds has been carried out in water-ethanol (50:50) under reflux conditions. The improvement of yield in this aqueous medium is attributed to a combination of increased association of the reactants by hydrophobic interactions and precipitation of the product during the reaction. This operationally simple procedure is less laborious and provides a better scope and chemoselectivity than previously reported procedures.
Palladium-catalyzed oxidative three-component tandem annulation reaction: Access to polysubstituted pyrroles