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@article{210915,
        author = {Pooja Sharma and Swarup J. Chatterjee},
        title = {Ash, Not Alchemy: Testing Bio-Waste Catalysts in Coumarin Synthesis},
        journal = {International Journal of Innovative Research in Technology},
        year = {2026},
        volume = {13},
        number = {6},
        pages = {2597-2607},
        issn = {2349-6002},
        url = {https://ijirt.org/article?manuscript=210915},
        abstract = {Burn an agricultural residue, extract the ash with water, and you have a cheap alkaline material that will drive a Knoevenagel condensation to coumarins at room temperature. A large and growing literature does exactly this and describes the result as a reusable heterogeneous catalyst. Each of those three words is a separate empirical claim, and each has a standard experiment attached to it that most papers do not report. This review sets out the claims and the tests. Reusable is established by elemental analysis of the filtrate and by comparing fresh with recovered solid, not by five cycles of unchanged yield, which Sheldon and co-workers showed long ago cannot exclude leaching. Heterogeneous is established by a hot-filtration or Sheldon test conducted at reaction temperature; a water extract of ash is a solution of soluble potassium salts and is homogeneous by definition, whatever it is called. Catalytic requires a turnover number, and loadings expressed as percent weight per volume frequently correspond to turnover numbers near unity, which describes a reagent. Green requires an E-factor or process mass intensity rather than the absence of an organic solvent in the reaction step alone. The chemistry constrains the claims further: the Knoevenagel route to coumarin-3-carboxylates is base-catalysed and an alkaline ash is a plausible catalyst for it, whereas the Pechmann route from phenols requires an acid and the same ash should be inactive a control that is almost never run. Reported coumarin bioactivity is then reviewed against the same standard: the aminocoumarin antibiotics have an established target in the DNA gyrase B ATPase, while radical-scavenging activity belongs to appended phenols rather than to the lactone.},
        keywords = {Coumarin; Knoevenagel condensation; agro-waste catalyst; heterogeneous catalysis; hot-filtration test; turnover number; DNA gyrase B},
        month = {November},
        }