摘要
The Keplerate‐type giant nanoporous isopolyoxomolybdate (NH4)42[MoVI72MoV60O372‐(CH3COO)30(H2O)72], denoted {Mo132}, has been used as a catalyst for the synthesis of1,2,4,5‐tetrasubstituted imidazoles by the one‐pot, four‐component thermal reaction of benzil with aromatic aldehydes, primary amines, and ammonium acetate under solvent‐free conditions. The catalyst was prepared according to a previously published literature procedure using inexpensive and readily available starting materials, and subsequently characterized by FT‐IR, UV and X‐ray diffraction spectroscopy, as well as microanalysis. The results showed that {Mo132} exhibited high catalytic activity towards the synthesis of 1,2,4,5‐tetrasubstituted imidazoles, with the desired products being formed in good to high yields. Furthermore, the catalyst was recyclable and could be reused at least three times without any discernible loss in its catalytic activity. Overall, this new catalytic method for the synthesis of 1,2,4,5‐tetrasubstituted imidazoles provides rapid access to the desired compounds following a simple work‐up procedure, and avoids the use of harmful organic solvents. This method therefore represents a significant improvement over the methods currently available for the synthesis of tetrasubstituted imidazoles.
The Keplerate-type giant nanoporous isopolyoxomolybdate (NH4)42[MoVI72MoV60O372-(CH3COO)30(H2O)72], denoted {Mo132}, has been used as a catalyst for the synthesis of 1,2,4,5-tetrasubstituted imidazoles by the one-pot, four-component thermal reaction of benzil with aromatic aldehydes, primary amines, and ammonium acetate under solvent-free conditions. The catalyst was prepared according to a previously published literature procedure using inexpensive and readily available starting materials, and subsequently characterized by FT-IR, UV and X-ray diffraction spectroscopy, as well as microanalysis. The results showed that{Mo132}exhibited high catalytic activity towards the synthesis of 1,2,4,5-tetrasubstituted imidazoles, with the desired products being formed in good to high yields. Furthermore, the catalyst was recyclable and could be reused at least three times without any discernible loss in its catalytic activity. Overall, this new catalytic method for the synthesis of 1,2,4,5-tetrasubstituted imidazoles provides rapid access to the desired compounds following a simple work-up procedure, and avoids the use of harmful organic solvents. This method therefore represents a significant improvement over the methods currently available for the synthesis of tetrasubstituted imidazoles.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第10期1761-1767,共7页
基金
the Islamic Azad University, Mashhad Branch for its financial support
关键词
取代咪唑
合成方法
可重复使用
纳米多孔
催化剂
E型
应用
催化活性
Giant Nanoporous
isopolyoxomolybdate
Keplerate
Solvent-free condition
1,2,4,5 -tetrasubstituted imidazole