Magnetic La0.7Sr0.3MnO3 nanoparticles: recyclable and efficient catalyst for ultrasound-accelarated synthesis of 4H-chromenes, and 4H-pyrano[2,3-c]pyrazoles
作者:Ali Azarifar、Razieh Nejat-Yami、Mohammad Al Kobaisi、Davood Azarifar
DOI:10.1007/s13738-012-0177-1
日期:2013.6
Nano magnetic complex lanthanum strontium magnesium oxide La0.7Sr0.3MnO3 (LSMO) has been explored as an efficient and recyclable catalyst to effect the one-pot three-component condensation reactions between aromatic aldehydes, malononitrile and 5,5-dimethyl-cyclohexane-1,3-dione, or 3-methyl-1-phenyl-2-pyrazolin-5-one in EtOH under ultrasound irradiation conditions. 2-Amino-5-oxo-5,6,7,8-tetrahydro-4H-chromenes and 1,4-dihydropyrano[2,3-c]pyrazol-5-yl cyanides were respectively synthesized from these reactions in high yields. This nano-catalyst can be easily recovered via magnetic concentration and reused without any significant drop in its catalytic activity. Magnetic La0.7Sr0.3MnO3 nanoparticles have been explored to efficiently catalyze the one-pot condensation of aromatic aldehydes, malononitrile and 5,5-dimethyl-cyclohexane-1,3-dione, or 3-methyl-1-phenyl-2-pyrazolin-5-one in EtOH under ultrasound-irradiation conditions. As a result, 2-Amino-5-oxo-5,6,7,8-tetrahydro-4H-chromenes and 1,4-dihydropyrano[2,3-c]pyrazol-5-yl cyanides were produced respectively in excellent yields. High efficiency, easy workup, high yields, use of cost-effective and non toxic catalyst are the main merits of this method.
研究发现,纳米磁性复合物
镧锶镁氧化物 La0.7Sr0.3MnO3 (LSMO) 是一种高效且可回收的催化剂,可在超声辐照条件下实现芳香醛、
丙二腈和 5,5-二甲基-
环己烷-1,3-二酮或 3-甲基-1-苯基-2-
吡唑啉-5-酮在 EtOH 中的一锅三组分缩合反应。这些反应分别高产合成了 2-
氨基-5-氧代-5,6,7,8-四氢-4H-苯并
吡唑和 1,4-二氢
吡喃并[2,3-c]
吡唑-5-
氰。这种纳米催化剂可以通过磁浓缩轻松回收并重复使用,其催化活性不会明显下降。研究人员探索了磁性 La0.7Sr0.3MnO3 纳米粒子在超声辐照条件下高效催化芳香醛、
丙二腈和 5,
5-二甲基-1,3-
环己烷二酮或 3-甲基-1-苯基-2-
吡唑啉-5-酮在 EtOH 中的一锅缩合反应。结果,2-
氨基-5-氧代-5,6,7,8-四氢-4H-苯并
吡唑和 1,4-二氢
吡喃并[2,3-c]
吡唑-5-基
氰化物分别以优异的收率生成。该方法的主要优点是效率高、操作简便、产率高、催化剂成本低且无毒。