Synthesis of biscoumarin derivatives by the reaction of aldehydes and 4-hydroxycoumarin using ruthenium (III) chloride hydrate as a versatile homogeneous catalyst

Abstract

The one-pot domino Knoevenagel-type condensation/Michael reaction of aromatic, heteroaromatic and aliphatic aldehydes with 4-hydroxycoumarin in aqueous media in the presence of ruthenium salt as homogeneous catalyst was investigated. It was found that 5 mol% of RuCl3.nH2O catalyzes biscoumarin synthesis in high yields (70-95%) under optimised, mild, green and environmentally benign reaction conditions in short times (25-35min)

A Rapid, Efficient and Green Method for Synthesis of 3,3'-Arylmethylene-bis-4-hydroxycoumarins without Use of any Solvent, Catalyst or Solid Surface

“…We feel that this protocol being a good addition to the currently reported methods 24,25 is in fact better than many others referred herein.…”

Coumarin and Biscoumarin Inhibit <i>in Vitro</i> Obesity Model

“…Biscoumarin (a 4-hydroxycoumarin dimer), another important class, has attracted great interest due to the novelity of its molecular structures and diverse biological properties. The presence of two intramolecular hydrogen bonds, and different substituents on the central linker methylene enables it to interact with various enzymes and receptors through weak bond interaction, thus exhibit versatile biological activities, for instance, antifungal, anti HIV, anticancer, antithrombotic, anticoagulant, antimicrobial and antioxidant [25]- [32], urease inhibitory [33], cytotoxicity and enzyme inhibitory activities [34]- [36]. In conclusion, coumarin derivatives in general, and biscoumarins, in particular, have received considerable attention because of their biological importance and numerous pharmacological activities.…”

Alkanedisulfamic Acid Functionalized Silica-Coated Magnetic Nanoparticles: Preparation and Catalytic Investigation in Synthesis of Mono-, Bis- and Tris[bis(4-hydroxycoumarinyl)methanes]

“…The recovery of the catalyst can also be a problem. Although the reaction of 4-hydroxycoumarin with monoaldehydes has been investigated, [11][12][13][14][15][16][17][18][19] there have been no reports on reactions of 4-hydroxycoumarin with di-or trialdehydes for the synthesis of bis-and tris[bis(4-hydroxycoumarinyl)methanes], respectively. As a continuation of our research on the preparation and catalytic investigation of new acid-functionalized magnetic nanoparticles, 3,20 we synthesized new alkanedisulfamic acid magnetic nanoparticles (ADSA-MNPs) by direct reaction of chlorosulfonic acid with diaminoalkylsilicacoated magnetic nanoparticles (Scheme 1), and we used these nanoparticles as a catalyst system for the synthesis of mono-, bis-, and tris[bis(4-hydroxycoumarinyl)methanes] by condensation of 4-hydroxycoumarin with mono-, di-, or trialdehydes, respectively.…”