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A novel magnetic hybrid nanocomposite was successfully synthesized via in situ polymerization, well characterized by FT-IR, XRD, EDX and FE-SEM analysis, and its catalytic activity shown in the synthesis of pharmaceutically important pyrans.

An efficient approach was reported for the synthesis of substituted 3-carboxycoumarins via a Knoevenagel condensation reaction between Meldrum's acid and substituted salicylaldehydes in the presence of a magnetic cellulose/Ag catalyst in EtOH at room temperature. This protocol includes many advantages such as remarkable magnetic properties of the nanobiocomposite catalyst, short reaction times, high yields and simple isolation of the organic products. In addition, the nanostructure catalyst can be easily separated from the reaction mixture and reused several times efficiently. Fourier transform infrared spectra, nuclear magnetic resonance spectra, X-ray diffraction pattern and field emission scanning electron microscopy images were performed for the characterisation of the products and the nanocatalyst.

A molecular iodine-mediated synthesis of angular oxatriqinane core from 3-acetyl-2H-chromen-2-ones, β-bromo-β-nitrostyrenes, and pyridine in the presence of Et3N in MeCN containing a trace amount of water was developed. The reaction proceeds via intermolecular Michael reaction of 2-oxo-2-(2-oxo-2H-chromen-3-yl)-1-(pyridin-1-ium-1-yl)­ethan-1-ide with bromonitrostyrene followed by intramolecular Michael reaction and elimination steps. Evidence for the stereochemistry of a typical product is obtained from single-crystal X-ray analyses. The important feature of this strategy is the fact that it forms three stereogenic centers with good selectivity.