Spinel-type zinc aluminate (ZnAl2O4) nanoparticles prepared by the co-precipitation method: A novel, green and recyclable heterogeneous catalyst for the acetylation of amines, alcohols and phenols under solvent-free conditions
Spinel-type zinc aluminate (ZnAl2O4) nanoparticles prepared by the co-precipitation method: A novel, green and recyclable heterogeneous catalyst for the acetylation of amines, alcohols and phenols under solvent-free conditions
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DOI：
10.1016/j.apcata.2010.05.005
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发表时间：
2010-07-15
影响因子：
5.5
通讯作者：
Panahandehjoo, Somayeh
中科院分区：
文献类型：
--
作者：
Farhadi, Saeid;Panahandehjoo, Somayeh
以氨水溶液为沉淀剂，采用共沉淀法制备了平均粒径约为8 nm的铝酸锌（ZnAl 2 O 4）纳米粒子。采用TGA、XRD、FT-IR、TEM和比表面积测定等手段对该纳米尖晶石型氧化物进行了表征，并将其用作乙酰化反应的非均相催化剂。采用乙酸酐和乙酰氯作为乙酰化剂，在室温下，不使用溶剂，在ZnAl 2 O 4纳米粒子上对各种胺、醇和酚类进行了高效的乙酰化反应。该方法是高度选择性的，允许醇羟基被保护而酚羟基保持完整，并且胺基可以在羟基存在下被乙酰化。该方法快速，产率高。它也是清洁的，安全的，具有成本效益的，与具有其他官能团的底物相容，非常适合于实际的有机合成。此外，该催化剂可以重复使用而不会显著损失活性。实际上，ZnAl 2 O 4纳米颗粒的催化活性高于块状ZnAl 2 O 4的催化活性。(c)2010 Elsevier B. V.保留所有权利。
Zinc aluminate (ZnAl2O4) nanoparticles with an average particle size of about 8 nm were easily prepared by the co-precipitation method using aqueous ammonia solution as the precipitating agent. This nano-sized spinel-type oxide was characterized by TGA, XRD, FT-IR, TEM, and surface area measurement and used as the heterogeneous catalyst for the acetylation reaction. Efficient acetylation of various amines, alcohols and phenols was carried out over ZnAl2O4 nanoparticles using acetic anhydride and/or acetyl chloride as the acetylating agents at room temperature without the use of a solvent. The method is highly selective, allowing the alcoholic hydroxyl group to be protected while the phenolic hydroxyl group remains intact, and the amine group can be acetylated in the presence of the hydroxyl group. This method is fast and has a high yield. It is also clean, safe, cost effective, compatible with substrates that have other functional groups and very suitable for practical organic synthesis. In addition, the catalyst can be reused without significant loss of activity. Indeed, the catalytic activity of the ZnAl2O4 nanoparticles is higher than that of bulk ZnAl2O4. (c) 2010 Elsevier B.V. All rights reserved.