催化学报 ›› 2014, Vol. 35 ›› Issue (3): 368-375.DOI: 10.1016/S1872-2067(12)60758-X

• 研究论文 • 上一篇    下一篇

ZnAl2O4@SiO2 nanocomposite catalyst for the acetylation of alcohols, phenols and amines with acetic anhydride under solvent-free conditions

Saeed Farhadi, Kosar Jahanara   

  1. Department of Chemistry, Lorestan University, Khoramabad 68135-465, Iran
  • 收稿日期:2013-09-21 修回日期:2013-11-28 出版日期:2014-02-26 发布日期:2014-02-26
  • 通讯作者: Saeed Farhadi

ZnAl2O4@SiO2 nanocomposite catalyst for the acetylation of alcohols, phenols and amines with acetic anhydride under solvent-free conditions

Saeed Farhadi, Kosar Jahanara   

  1. Department of Chemistry, Lorestan University, Khoramabad 68135-465, Iran
  • Received:2013-09-21 Revised:2013-11-28 Online:2014-02-26 Published:2014-02-26
  • Contact: Saeed Farhadi

摘要:

A ZnAl2O4@SiO2 nanocomposite was prepared from metal nitrates and tetraethyl orthosilicate by the sol-gel process, and characterized by X-ray diffraction, Fourier transform infrared, transmission electron microscopy, and N2 adsorption-desorption measurements. The nanocomposite was tested as a heterogeneous catalyst for the acetylation of alcohols, phenols, and amines under solvent-free conditions. Under optimized conditions, efficient acetylation of these substrates with acetic anhydride over the ZnAl2O4@SiO2 nanocomposite was obtained. Acetylation of anilines and primary aliphatic amines proceeded rapidly at room temperature, while the reaction time was longer for the acetylation of alcohols and phenols, showing that an amine NH2 group can be selectively acetylated in the presence of alcoholic or phenolic OH groups. The catalyst can be reused without obvious loss of catalytic activity. The catalytic activity of the ZnAl2O4@SiO2 nanocomposite was higher than that of pure ZnAl2O4. The method gives high yields, and is clean, cost effective, compatible with substrates having other functional groups and it is suitable for practical organic synthesis.

关键词: Spinel-type oxide, Zinc aluminate, Silica, Sol-gel process, Nanocomposite, Heterogeneous catalyst, Acetylation, Solvent-free condition

Abstract:

A ZnAl2O4@SiO2 nanocomposite was prepared from metal nitrates and tetraethyl orthosilicate by the sol-gel process, and characterized by X-ray diffraction, Fourier transform infrared, transmission electron microscopy, and N2 adsorption-desorption measurements. The nanocomposite was tested as a heterogeneous catalyst for the acetylation of alcohols, phenols, and amines under solvent-free conditions. Under optimized conditions, efficient acetylation of these substrates with acetic anhydride over the ZnAl2O4@SiO2 nanocomposite was obtained. Acetylation of anilines and primary aliphatic amines proceeded rapidly at room temperature, while the reaction time was longer for the acetylation of alcohols and phenols, showing that an amine NH2 group can be selectively acetylated in the presence of alcoholic or phenolic OH groups. The catalyst can be reused without obvious loss of catalytic activity. The catalytic activity of the ZnAl2O4@SiO2 nanocomposite was higher than that of pure ZnAl2O4. The method gives high yields, and is clean, cost effective, compatible with substrates having other functional groups and it is suitable for practical organic synthesis.

Key words: Spinel-type oxide, Zinc aluminate, Silica, Sol-gel process, Nanocomposite, Heterogeneous catalyst, Acetylation, Solvent-free condition