the viability of a wide range of crystalline aromatic and aliphatic carboxylic acids as organocatalysts has been investigated for solvent-free Paal–Knorr pyrrole synthesisundermicrowave activation. Among these potential catalysts, crystalline salicylic acid proved to be a remarkable catalyst because its efficiency remained high even under low microwave power irradiation or a shorter reaction time
摘要 在这项研究中,已经研究了微波活化下无溶剂的Paal-Knorr吡咯合成中各种结晶性芳族和脂肪族羧酸作为有机催化剂的可行性。在这些潜在的催化剂中,结晶水杨酸被证明是出色的催化剂,因为即使在低微波功率辐照下或模型反应的反应时间较短的情况下,其效率仍然很高。水杨酸出色的催化活性使Paal–Knorr环缩合的周转频率高达1472 h -1,这在无金属均相催化的情况下是独一无二的。这种有机催化剂的吸引人的特点是它有助于超快速的吡咯合成,并且没有金属污染的风险。 图形摘要 概要:引入了一种绿色快速的方法,该方法通过水杨酸作为催化剂(固态)与微波的组合来合成2,5-二甲基吡咯。
Microwave-induced calcium(II) chloride-catalyzed Paal–Knorr pyrrole synthesis: a safe, expeditious, and sustainable protocol
alkaline-earth (Ca, Mg, Sr, Ba) chlorides, calcium(II) chloride was found to be a cost-effective Lewis acid catalyst for solvent-free synthesis of pyrroles from primary aromatic and aliphaticamines under open-vessel focused microwave irradiation. The salient features of this environmentally benign method are high to quantitative conversion, short reaction time, safe and clean reaction profile, possibility of
A convenient synthesis of pyrroles catalyzed by acidic resin under solvent-free condition
作者:Shi Zhen Yuan、Jin Liu、Ling Xu
DOI:10.1016/j.cclet.2010.01.038
日期:2010.6
5-hexanedione with most amines have been carried out at room temperature under solvent-free condition. Macroporous strongly acidic styrol resin (D001) as a novel, efficient, cost-effective, and reusable solid acid catalyst for the synthesis of pyrroles under the same conditions. The pyrroles were obtained in high yields in short reaction times.
Bio-based Material as Medium, Mild and Reusable Catalyst for Paal– Knorr Pyrrole Synthesis with and Without Ultrasonic Irradiation
作者:Abha Sharma、Illa Siva Kalyani、Anam Fatima
DOI:10.2174/1570178614666170711145253
日期:2018.2.7
a simple, mild and speedy synthesis of N-substituted 2,5-dimethyl pyrrole derivatives in ‘’GAAS’’ as medium and catalyst at room temperature and under ultrasound irradiation. Results: This protocol was employed for the synthesis of various 2,5-dimethyl-N-substituted pyrrolederivatives using both aliphatic as well as aromatic amines in short time (2 to 10 minutes)with excellent yield (84-95%) at room
COF@Fe3O4 under hydrothermal conditions for the first time. The high surface area magnetic COF could exhibit superior catalytic activity for sustainable synthesis of trisubstituted and tetrasubstituted imidazoles and pyrroles in good to excellent yields in PEG as solvent under environmentally friendly, ambient conditions and making the overall process economical, efficient, and green. The retrievable
为环境良性过程的广泛应用设计廉价而高效的纳米多孔磁性催化剂是一个极具吸引力且具有挑战性的化学研究领域。通过三聚氰胺与对苯二醛在3,4-二羟基苯甲醛包覆磁性Fe 3 O 4纳米颗粒COF@Fe 3 O 4表面缩合反应制备新型多孔磁性共价有机骨架第一次在热液条件下。高表面积磁性 COF 可以在环境友好、环境条件下以 PEG 作为溶剂的良好收率,对三取代和四取代咪唑和吡咯的可持续合成表现出优异的催化活性,并使整个过程经济、高效和绿色。PEG中的可回收催化剂是通用的,适用于广泛的底物范围和官能团兼容性。通过FTIR、XRD、EDX和SEM光谱对COF@Fe 3 O 4的结构和形貌进行了表征。COF@Fe 3 O 4 磁性催化剂通过外部磁铁回收并使用多个循环而没有显着的催化活性损失。