A novel basic ionic liquid, 1-(2-aminoethyl)pyridinium hydroxide, containing both Brønsted base and Lewis base sites has been used as an efficient catalyst for the synthesis of 2-amino-4-phenyl-6-(phenylsulfanyl)-3,5-dicyanopyridines. The condensation and oxidation tandem reaction of aldehydes, malononitrile, and thiols, performed in aqueous ethanol, afforded reasonable to good yields within 30–60 min. After the reaction, the catalyst could be recycled and reused. A possible mechanism to account for the tandem reaction is proposed. .
An Improved Procedure for the Three-Component Synthesis of Highly Substituted Pyridines Using Ionic Liquid
作者:Brindaban C. Ranu、Ranjan Jana、S. Sowmiah
DOI:10.1021/jo070015g
日期:2007.4.1
A basicionicliquid, [bmIm]OH, efficiently promotes a one-pot, three-component condensation of aldehydes, malononitrile, and thiophenols to produce highly substituted pyridines in high yields at room temperature. This reaction does not involve any hazardous organic solvent and toxic catalyst. The ionicliquid is recovered and recycled for subsequent reactions.
Scandium triflate-catalyzed one-pot multi-component synthesis of 2-amino-6-thiopyridine-3,5-dicarbonitriles
作者:Shrinivas S. Kottawar、Shapi A. Siddiqui、Sudhakar R. Bhusare
DOI:10.1515/hc-2012-0103
日期:2012.12.1
Abstract Scandium triflateefficiently promotes a one-pot, three-component condensation of aldehydes, malononitrile, and thiophenols to produce highly substituted pyridines in good yields. This reaction does not involve any hazardous organic solvent and toxic catalyst.
Natural dolomitic limestone (NDL) is employed as a heterogeneous green catalyst for the synthesis of medicinally valuable benzimidazoles, dihydropyrimidinones, and highly functionalized pyridines via C–N, C–C, and C–S bond formations in a mixture of ethanol and H2O under ultrasound irradiation. The catalyst is characterized by XRD, FTIR, Raman spectroscopy, SEM, and EDAX analysis. The main advantages
One-step, three-component synthesis of highly substituted pyridines using silica nanoparticle as reusable catalyst
作者:Subhash Banerjee、Grigoriy Sereda
DOI:10.1016/j.tetlet.2009.09.137
日期:2009.12
One-stepsynthesis of ‘privileged medicinal scaffolds’, 2-amino-3,5-dicarbonitrile- 6-sulfanylpyridines, has been demonstrated via a multicomponent reaction of aldehydes, malononitrile, and thiols using silica nanoparticle (NP) as catalysts. The silica NP catalysts are very mild (nearly neutral in nature), effective, environmentally benign, and retain most of their activities after being reused for