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Abstract: In the present work, we explored novel CeZrO4−δ as a catalyst for Knoevenagel condensation of aldehydes with reactive methylene compounds like malononitrile and ethylcyanoacetate. For the present study, ceria, zirconia and CeZrO4−δ were prepared by gel combustion method and well characterized using XRD, SEM, EDX, BET and TPD analyses, etc. A wide range of aldehydes were effectively condensed over novel CeZrO4−δ with reactive methylene compounds with high yields. In addition, the CeZrO4−δ was effectively reused for five consecutive cycles without significant loss in its activity. To the best of our knowledge, this is the first liquid-phase application of pure CeZrO4−δ.Graphical abstract: [ABSTRACT FROM AUTHOR]

Hexagonal mesoporous silica (HMS)-supported copper oxides (CuO/HMS) have been prepared by a sol-gel method and characterized by X-ray diffraction, FTIR spectroscopy, transmission electron microscopy, N2 sorption, inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS), H2 temperatureprogramed reduction (TPR), NH3 temperature-programed desorption (TPD), and high-resolution (HR)-TEM techniques. An analysis of these results revealed a mesoporous material system with a high surface area (974 m2g-1) and uniform poresize distribution. The catalytic efficacy of CuO on the HMS support with varying Cu loadings (1, 3, 5, 10, and 15 wt%) was investigated for the transformation of aldehydes to primary amides; 3wt% CuO/HMS exhibited good catalytic performance with good to excellent yields of amides (60-92%) in benign aqueous medium. The intrinsically heterogeneous catalyst could be recovered after the reaction and reused without any noticeable loss in activity. [ABSTRACT FROM AUTHOR]

Mixed metal oxides such as ZrO2–NiO, ZrO2–CoO, and ZrO2–Fe2O3 effectively reduce nitro arenes, aldehydes and ketones with propan-2-ol and KOH/NaOH in liquid phase reaction. The catalysts also have considerable level of reusability. [ABSTRACT FROM AUTHOR]

Sulfated zirconia results to be a very efficient catalyst for the synthesis of 1,8-dioxo-octahydroxanthenes and 1,8-dioxo-decahydroacridines without tedious work-up procedures. While 1,8-dioxo-octahydroxanthenes are prepared from aldehyde and 5,5-dimethyl-1,3-cyclohexenedione (dimedone), 1,8-dioxo-decahydroacridines are prepared from this reactant mixture with amines. This method provides a mild catalytic protocol for the synthesis of functionalized xanthene and acridine derivatives. The catalysts were characterized by XRD, FT-IR, TGA-DSC, SEM-EDAX and surface acidity and showed excellent re-usability up to 6 consecutive cycles. [ABSTRACT FROM AUTHOR]