First Example of Organocatalysis by Polystyrene-Supported PAMAM Dendrimers: Highly Efficient and Reusable Catalyst for Knoevenagel Condensations
作者:G. Rajesh Krishnan、Krishnapillai Sreekumar
DOI:10.1002/ejoc.200800516
日期:2008.10
This paper describes the first use of polystyrene-supported poly(amidoamine) (PAMAM) dendrimers as heterogeneous basic organocatalysts for carbon–carbon bond formation. Polystyrene-supported PAMAM dendrimers of first, second and third generations have been used as reusable base catalysts in Knoevenagel condensations of carbonyl compounds with active methylene compounds. The reactions proceed in short
本文描述了聚苯乙烯负载的聚(酰胺胺)(PAMAM)树枝状大分子作为碳-碳键形成的多相碱性有机催化剂的首次使用。第一代、第二代和第三代聚苯乙烯负载的 PAMAM 树枝状大分子已被用作可重复使用的碱催化剂,用于羰基化合物与活性亚甲基化合物的 Knoevenagel 缩合反应。反应在短时间内以 100% 的选择性进行。这种新型催化剂无需使用芳香族和卤化溶剂,也无需复杂的纯化过程。催化剂可以循环使用 10 次。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)