Zirconia Sulfuric Acid: An Efficient Heterogeneous Catalyst for the One-Pot Synthesis of 3,4-Dihydropyrimidinones Under Solvent-Free Conditions

12‐Tungstosilicic Acid H4[W12SiO40] Over Natural Bentonite as a Heterogeneous Catalyst for the Synthesis of 3,4‐dihydropyrimidin‐2(1H)‐Ones

“…This shows that this procedure is environmentally benign. In comparision for model reaction (benzaldehyde, ethylacetoacetate and urea), this catalyst did not exhibit at par catalytic activity as compared to Fe 3 O 4 @SiO 2 ‐imid‐PMA n (93 %), AT‐Mont (98 %), MCM‐41‐R‐SO 3 H (92 %), PAFMS‐1 (92 %), ZrO2@SO 3 H (92 %), PTA@MIL‐101 (90 %) and TPA & TSA over MCM‐41(94 % and 92 %) and Hβ(98 % and 95 %) …”

“…Patil et al recently extensively reviewed usage of different kind of supports as a heterogeneous catalyst for this reaction . A notable solid acid catalysts such as silica sulfuric acid, MCM‐41‐SO 3 H, PS‐PEG‐SO 3 H, Al 2 O 3 /MeSO 3 H, bio‐glycerol‐SO 3 H, Fe 3 O 4 @SBA‐15‐COOH, PPF‐SO 3 H, Fe 3 O 4 /PAA‐SO 3 H, BPMO‐IL‐SO 3 H, SiO 2 ‐Pr‐SO 3 H, nano‐γ‐Fe 2 O 3 ‐SO 3 H, perlite‐SO 3 H, nano‐ZrO 2 ‐SO 3 H, Fe 3 O 4 @SiO 2 ‐PhSO 3 H, SiO 2 ‐phosphonicacid, β‐cyclodextrin‐propylsulfonicacid, ZrO 2 ‐SO 3 H, GO‐SO 3 H, halogenated macroporous sulfonic resin and Fe 3 O 4 @meglumine‐SO 3 H that delivered DHPMs in high yields with good reusability. In spite of exploring the different type of material as a catalyst for this one‐pot condensation reaction, there is still scope to find a novel catalyst system which is easily available and can mitigate the above mentioned problems.…”

Nano-sized glass as an economically viable and eco-benign support to anchor heteropolyacids for green and sustainable chemoselective oxidation of sulfides to sulfoxides

“…Among heteropolyacids, we chose phosphomolybdic acid (PMA) because it is one of the least expensive commercially available one. In continuation of our attempts for the preparation of different solid acid catalyst, [21][22][23][24][25][26][27][28] the present study consists of the synthesis of a novel solid acid nanocatalyst named nano-glass waste-supported phosphomolybdic acid (n-GW/PMA) and its application for the facile, fast, highly efficient, and chemoselective oxidation of sulfides to sulfoxides in the presence of H 2 O 2 as oxidant under solvent-free conditions. Afterwards, the newly synthesized n-GW/PMA was fully characterized through FT-IR, EDX, FE-SEM and TGA techniques.…”

Magnetic carbon nanotube as a highly stable and retrievable support for the heterogenization of sulfonic acid and its application in the synthesis of 2‐(1H‐tetrazole‐5‐yl) acrylonitrile derivatives

“…Continuing our previous research on the expansion of new heterogeneous catalysts, for the first time, we used magnetic CNTs as a highly stable support for the heterogenization of sulfonic acid for the preparation of Fe 3 O 4 ‐CNT‐SO 3 H nanocomposite and studied its catalytic activity in the convenient and green preparation of tetrazoles via multicomponent domino Knoevenagel condensation/1,3‐dipolar cycloaddition reaction between aldehydes, malononitrile, and sodium azide.…”