Abstract Lithium tetrafluoroborate has been demonstrated for the first time to be an efficient catalyst in intermolecular aza-Michael addition aromatic amines to electron deficient alkenes. Suitability of the same catalyst in intramolecular aza-Michael addition leading 2-aryl-2,3-dihydroquinolin-4(1H) ones has also been described.
Ytterbium(III) triflate: An efficient and simple catalyst for isomerization of 2′-hydroxychalcone and 2′-aminochalcones in ionic liquid
作者:V. Kameswara Rao、M. Sudershan Rao、Anil Kumar
DOI:10.1002/jhet.760
日期:2011.11
Isomerization of 2′‐hydroxychalcone and 2′‐aminochalcone have been investigated using ytterbium(III) trifluromethanesulfonate Yb(OTf)3} (30 mol %) as Lewis acid catalyst in [bmim][BF4] ionicliquid. The effect of different metal triflates as Lewis acid, catalyst loading and reaction media was studied for this isomerization reaction. Advantages of the methodology include short reaction time, excellent
Silica-gel-supported Ce(SO<sub>4</sub>)<sub>2</sub>·4H<sub>2</sub>O-mediated cyclization of 2′-amino and 2′-hydroxychalcones under solvent-free conditions
作者:Ruihuan Liu、Yan Zhang、Kangping Xu、Guishan Tan
DOI:10.1080/00397911.2016.1230217
日期:2017.1.2
efficient, and environmentally friendly approach for the synthesis of flavones, aza-flavones, and aza-flavanones from corresponding 2′-hydroxy or 2′-aminochalcones has been developed. The reactions are successfully conducted in presence of silica-gel-supported Ce(SO4)2·4H2O under solvent-free conditions. GRAPHICAL ABSTRACT
Simple and Efficient Synthesis of 2-Aryl-2,3-Dihydroquinolin-4(1<i>H</i>)-ones Using Silica Chloride as a New Catalyst Under Solvent-Free Conditions
作者:M. Muthukrishnan、M. Mujahid、V. Punitharasu、D. A. Dnyaneshwar
DOI:10.1080/00397910903097252
日期:2010.4.12
A mild, efficient, and high-yielding method for the synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones from their corresponding 2-amino chalcones using silica chloride (SiO2Cl) under solvent-free conditions is described. A series of 2-aryl-2,3-dihydroquinolin-4(1H)-ones containing both electron-donating and electron-withdrawing substituents were synthesized.
A new, convenient, and efficient method for the intramolecular aza-Michaeladditionreaction of 2′-aminochalcones is developed using 1-n-butyl-3-methylimidazolium tetrafluoroborate as the solvent and catalyst. The ionicliquid is successfully regenerated and reused.