A convenient synthesis of coumarinyl chalcones using HClO4–SiO2: A green approach

Abstract

Graphical abstractA simple and efficient one-pot synthesis of coumarinyl chalcones was reported in the presence of silica supported perchloric acid under solvent-free heating at 80 °C in excellent yields. The catalyst was recycled for four runs without any loss of its catalytic activity. AbstractHClO 4 -SiO 2 catalysed synthesis of coumarinyl chalcones (8a-j) under solvent-free conditions is reported. The catalyst is characterized by powder XRD and SEM-EDX analysis. The stability of the catalyst is evaluated by thermogravimetric (TG) and differential scanning calorimetry (DSC) techniques. The remarkable features of this green protocol are excellent yields of the products, shorter reaction time, simple experimental procedure, easy preparation and reusability of the catalyst.

Synthesis and Antioxidant Activity of (E)-3-(3-(4-Oxo-4h-Chromen-3-Yl)acryloyl) 2h-Chromen-2-One Derivatives

“…Производные (E)-3-(3-(4-оксо-4H-хромен-3-ил) акрилоил)-2H-хромен-2-она получают конденсацией 3-формилхромона с 3-ацетилкумарином в спирте с использованием в качестве катализатора органиче-ских оснований -N,N-диметиламинопиридина [21] или пиперидина [22]. Для этой реакции в различных условиях изучены каталитические свойства кислот Льюиса [23,24]. Однако, на наш взгляд, данный синтетический подход не может быть применен при введении во взаимодействие 3-формилхромона ввиду высокой реакционной способности положения С(2): в присутствии даже слабых нуклеофилов происходит раскрытие пиронового цикла с формированием замещенных фенолов.…”

Recent Strategies for Efficient Synthesis and Biological Activities of Coumarin-Chalcone Derivatives

“…Siddiqui [88] reported the green synthesis of coumarinyl chalcones by mixing of aldehyde, heterocyclic methyl ketones, and HClO 4 -SiO 2 and heated at 80°C for specified time.…”

Expedient approach for trans-esterification of β-keto esters under solvent free conditions using silica supported boric acid (SiO2–H3BO3) as a recyclable catalyst

“… 40 a – c The development of selective and reusable solid support catalysts for organic reactions has been a very active area of research because of their reusability by filtration that not only simplify purification processes but also help in preventing the discharge of toxic reaction residues into the environment. During the last few decades, silica-supported catalysts have achieved considerable attention 41 among the synthetic and material sciences community. Silica supported H 2 SO 4 , HClO 4 , PPA, HBF 4 , NaHSO 4 , P 2 O 5 , FeCl 3 , H 3 BO 3 etc.…”