Synthesis of functionalized benzimidazoles and quinoxalines catalyzed by sodium hexafluorophosphate bound Amberlite resin in aqueous medium
作者:Pranab Ghosh、Amitava Mandal
DOI:10.1016/j.tetlet.2012.09.045
日期:2012.11
for the selective synthesis of 1,2-disubstitutedbenzimidazoles and quinoxalines in water–methanol (1:1) mixture with the aid of resin bound hexafluorophosphate ion as catalyst is reported. The method is also effective for the incorporation of quinoxaline nucleus at the A ring of pentacyclic triterpenoid, friedelin. A plausible mechanism for the formation of disubstituted benzimidazole has also been suggested
A range of Lewis acidic ionic liquids composed of crownethercomplexcations were designed, synthesised and characterised by Raman, MS, FT-IR, thermogravimetric differential thermal analysis (TGA-DSC) and elemental analysis. These Lewis acidic ionic liquids were utilized as catalysts to prepare 2-phenyl-1H-benzo[d]imidazole using the same amount of aldehyde and o-phenylenediamine under air atmosphere
设计,合成和表征了一系列由冠醚络合物阳离子组成的路易斯酸性离子液体,并通过拉曼光谱,质谱,傅立叶变换红外光谱,热重差热分析(TGA-DSC)和元素分析进行了表征。这些路易斯酸性离子液体被用作催化剂,在空气气氛下使用相同量的醛和邻苯二胺和1-苄基-2-苯基-1 H-苯并[ ]制备2-苯基-1 H-苯并[ d ]咪唑。d ]咪唑,使用两当量的醛和一当量的o-苯二胺在氩气中。还发现这些离子液体是在温和条件下合成双(吲哚基)甲烷衍生物的良好催化剂。另外,提出并讨论了在离子液体作为催化剂存在下上述反应的合理机理。
Catalytic role of sodium dodecyl sulfate: Selective synthesis of 1, 2-disubstituted benzimidazoles in water
作者:Pranab Ghosh、Amitava Mandal
DOI:10.1016/j.catcom.2011.01.005
日期:2011.3
A simple and efficient procedure for the synthesis of 1, 2-disubstituted benzimidazoles has been developed by a one-pot reaction of o-phenylenediamine with both aromatic and aliphatic aldehydes in the presence of sodiumdodecylsulfate in aqueousmedium at roomtemperature in open air without any organic solvent. The surfactant is recycled. A plausible mechanistic approach has also been suggested.
A Green Route for the One-Pot Synthesis of 1,2-Disubstituted Benzimidazoles Using Iron(III) Phosphate under Solventless Conditions
作者:F. K. Behbahani、Parisa Ziaei
DOI:10.1002/cjoc.201180461
日期:2012.1
1,2‐Disubstituted benzimidazoles are selectively synthesized in high yields under extremely mild conditions via the condensation of o‐phenylenediamine derivatives with aldehyde derivatives using catalytic amount of iron(III) phosphate under solvent‐free conditions. The use of readily available iron(III) phosphate as a reusable and recyclable catalyst makes this process quite simple, convenient, and
Water mediated chemoselective synthesis of 1,2-disubstituted benzimidazoles using o-phenylenediamine and the extended synthesis of quinoxalines
作者:Jie-Ping Wan、Shi-Feng Gan、Jian-Mei Wu、Yuanjiang Pan
DOI:10.1039/b914286j
日期:——
By applying water as the reaction medium, the one-pot synthesis of 1,2-disubstituted benzimidazoles has been achieved in excellent efficiency and selectivity at room temperature viatrimethylsilyl chloride promoted reaction of o-phenylenediamine with aldehyde. This green catalyst system has also been successfully extended to the synthesis of quinoxalines via the reaction of o-phenylenediamine with α-bromoketone. Water displayed a specific functionality in mediating the selectivity, and remarkable advantages over organic solvents in terms of yields as well as in the work up procedure of the reactions.