催化学报 ›› 2014, Vol. 35 ›› Issue (3): 444-450.DOI: 10.1016/S1872-2067(14)60009-7

• 研究论文 • 上一篇    下一篇

SiO2-Cu2O:An efficient and recyclable heterogeneous catalyst for N-benzylation of primary and secondary amines

Manjulla Gupta, Satya Paul, Rajive Gupta   

  1. Department of Chemistry, University of Jammu, Jammu-180 006, India
  • 收稿日期:2013-09-16 修回日期:2013-12-24 出版日期:2014-02-26 发布日期:2014-02-26
  • 通讯作者: Satya Paul

SiO2-Cu2O:An efficient and recyclable heterogeneous catalyst for N-benzylation of primary and secondary amines

Manjulla Gupta, Satya Paul, Rajive Gupta   

  1. Department of Chemistry, University of Jammu, Jammu-180 006, India
  • Received:2013-09-16 Revised:2013-12-24 Online:2014-02-26 Published:2014-02-26
  • Contact: Satya Paul

摘要:

A mild, effective, and selective procedure is reported for the mono N-benzylation and N,N-dibenzylation of primary amines as well as mono N-benzylation of secondary amines using silica-supported copper(I) oxide in water. The silica-supported Cu2O was generated in situ by the reaction of Fehling solution and glucose at 100 ℃ onto activated silica. The catalyst was filtered, washed with water, and oven-dried, and was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, and atomic absorption spectroscopy. The prepared Cu2O-SiO2 was found to be thermally stable up to 325 ℃. The copper was uniformly distributed onto the surface of the silica, and the mean particle diameter was 7 nm. The catalyst served as a selective heterogenous catalyst for the N-benzylation of primary and secondary amines. The catalyst is recyclable and was used effectively upto fifth run without a significant loss of catalytic activity. Various reaction solvents including water, acetonitrile, and toluene were screened for N-benzylation of amines, and the success of the aqueous system highlights the low environmental impact of the procedure.

关键词: Silica supported copper(I) oxide, Benzylation, Substituted amine, Recyclability, Heterogeneous catalysis

Abstract:

A mild, effective, and selective procedure is reported for the mono N-benzylation and N,N-dibenzylation of primary amines as well as mono N-benzylation of secondary amines using silica-supported copper(I) oxide in water. The silica-supported Cu2O was generated in situ by the reaction of Fehling solution and glucose at 100 ℃ onto activated silica. The catalyst was filtered, washed with water, and oven-dried, and was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, and atomic absorption spectroscopy. The prepared Cu2O-SiO2 was found to be thermally stable up to 325 ℃. The copper was uniformly distributed onto the surface of the silica, and the mean particle diameter was 7 nm. The catalyst served as a selective heterogenous catalyst for the N-benzylation of primary and secondary amines. The catalyst is recyclable and was used effectively upto fifth run without a significant loss of catalytic activity. Various reaction solvents including water, acetonitrile, and toluene were screened for N-benzylation of amines, and the success of the aqueous system highlights the low environmental impact of the procedure.

Key words: Silica supported copper(I) oxide, Benzylation, Substituted amine, Recyclability, Heterogeneous catalysis