Silica-supported molybdic acid: preparation, characterization, and its catalytic application in synthesis of pyranocoumarins

A novel magnetic FSM-16 supported ionic liquid/Pd complex as a high performance and recyclable catalyst for the synthesis of pyrano[3,2-c]chromenes

In this work, Fe3O4@FSM-16/IL-Pd was successfully designed and synthesized via a new procedure of palladium(ii) complex immobilization onto magnetic FSM-16 using an ionic liquid, as a novel heterogeneous nanocatalyst. Multiple techniques were employed to characterize this magnetic nanocatalyst such as Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), Field Emission Scanning Electron Microscopy (FE-SEM), thermogravimetric analysis (TGA), Transmission electron microscopy (TEM), and Vibrating Sample Magnetometry (VSM). After complete characterization of the catalyst, its catalytic activity was used for the synthesis of pyrano[3,2-c]chromene-3-carbonitriles via the reaction of 4-hydroxycoumarin, aldehyde, and malononitrile under solvent-free conditions. Also, it can be recovered and reused several times without a significant decrease in its catalytic activity or palladium leaching.

Multicomponent Synthesis Strategies, Catalytic Activities, and Potential Therapeutic Applications of Pyranocoumarins: A Comprehensive Review

Fused coumarins, because of their remarkable biological and therapeutic properties, particularly pyranocoumarins, have caught the interest of synthetic organic chemists, leading to the development of more efficient and environmentally friendly protocols for synthesizing pyranocoumarin derivatives. These compounds are the most promising heterocycles discovered in both natural and synthetic sources, with anti-inflammatory, anti-HIV, antitubercular, antihyperglycemic, and antibacterial properties. This review employed the leading scientific databases Scopus, Web of Science, Google Scholar, and PubMed up to the end of 2022, as well as the combining terms pyranocoumarins, synthesis, isolation, structural elucidation, and biological activity. Among the catalysts employed, acidic magnetic nanocatalysts, transition metal catalysts, and carbon-based catalysts have all demonstrated improved reaction yields and facilitated reactions under milder conditions. Herein, the present review discusses the various multicomponent synthetic strategies for pyranocoumarins catalyzed by transition metal-based catalysts, transition metal-based nanocatalysts, transition metal-free catalysts, carbon-based nanocatalysts, and their potential pharmacological activities.

Synthesis and characterization of molybdic acid immobilized on modified magnetic nanoparticles as a new and recyclable catalyst for the synthesis of chromeno[4,3-b]chromenes

Synthesis and characterization of molybdic acid immobilized on modified magnetic nanoparticles as a new catalyst is reported.