Department of Chemistry, University of Delhi, Delhi, India.
PLoS One. 2012;7(8):e43078. doi: 10.1371/journal.pone.0043078. Epub 2012 Aug 17.
We recently reported a novel synthesis of copper nanoparticles from copper sulphate utilizing the charge-compensatory effect of ionic liquid [bmim]BF(4) and ethylene glycol. The nanoparticles were characterized and found to be stable for one year. Here we hypothesize that the stabilized nanoparticles should be able to catalyze one-pot multicomponent organic reactions. We show that the nanoparticles catalyzed Biginelli reaction at room temperature to give the product 3,4-dihydopyrimidinone (>90% yield in ~15 minutes) from aldehydes, β-diketoester (ethylacetoacetate) and urea (or thiourea). ). Remarkably, such high yields and rapid kinetics was found to be independent of the electronic density on the reactant aryl-aldehyde. This was probably because even the surface-active particles reacted faster in the presence of ionic liquid as compared to conventional methods. The heterocyclic dihydropyrimidinones (DHPMs) and their derivatives are widely used in natural and synthetic organic chemistry due to their wide spectrum of biological and therapeutic properties (resulting from their antibacterial, antiviral, antitumor and anti-inflammatory activities. Our method has an easy work-up procedure and the nanoparticles could be recycled with minimal loss of efficiency.
我们最近报道了一种利用离子液体[bmim]BF(4)和乙二醇的电荷补偿效应从硫酸铜合成纳米铜的新方法。对纳米粒子进行了表征，发现其在一年内稳定。在这里，我们假设稳定的纳米粒子应该能够催化一锅多组分有机反应。我们表明，纳米粒子在室温下催化了Biginelli 反应，从醛、β-二酮酯（乙酰乙酸乙酯）和脲（或硫脲）得到产物 3,4-二氢嘧啶酮（在 15 分钟内产率大于 90%）。值得注意的是，这种高产率和快速动力学与反应物芳基醛的电子密度无关。这可能是因为即使是表面活性的粒子，在离子液体存在下的反应速度也比传统方法快。杂环二氢嘧啶酮（DHPMs）及其衍生物由于其广泛的生物和治疗特性（由于其抗菌、抗病毒、抗肿瘤和抗炎活性）而广泛应用于天然和合成有机化学中。我们的方法具有简单的后处理程序，并且纳米粒子可以在最小效率损失的情况下回收。
