Three‐Component Mannich Reaction Catalyzed by Mesostructured Cellular Foam Silica Immobilized H₃PW₁₂O₄₀

Abstract

One-pot three-component Mannich reaction was carried out at room temperature using mesocellular cellular foam (MCF) silica loaded H 3 PW 12 O 40 as catalyst. The H 3 PW 12 O 40 /MCF catalyst was prepared by the traditional impregnation method and confirmed by a series of characterizations such as nitrogen adsorption, X-ray diffraction (XRD), Fourier-transform infrared spectra (FT-IR), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results showed that the H 3 PW 12 O 40 /MCF catalyst with 50 wt% loading of H 3 PW 12 O 40 exhibited the highest catalytic activity for the Mannich reaction of benzaldehyde, aniline and acetophenone with the yield of 94% in 1.8 hours under the optimal condition. In addition, the H 3 PW 12 O 40 /MCF catalyst could be easily recycled and reused four times without significant decline of activity. This work provided an improved modification of the three-component Mannich reaction in terms of efficient activity, mild reaction conditions, clean reaction profiles and a simple workup procedure.

Perovskite LaNiO3 Nanocrystals inside Mesostructured Cellular Foam Silica: High Catalytic Activity and Stability for CO2 Methanation

“…It is shown that the MCF material exhibits a typical type‐IV isotherm with a hysteresis loop of H1 . According to the literature, large cells ( D c , around 35 nm) of MCF material are connected to each other through narrow windows ( D w , around 22 nm), which is a mesoporous material with a spherical hole–type structure. Overall, the nitrogen adsorption–desorption isotherms of x LNOM‐C‐ y are similar with that of MCF, indicating that the porous structure still remains after the addition of different amounts of LaNiO 3 species using the citric acid–assisted impregnation.…”

“…MCF has been utilized in many fields such as adsorption, separation, and catalysis because of its unique pore characteristics of a high surface area and large pore volume . For example, H 3 PW 12 O 40 /MCF catalyst was used for Mannich reaction, and the results showed that the catalyst exhibited a high surface area and large pore volume without the blockage of pores, even when the loading of H 3 PW 12 O 40 was as high as 50 wt% . This cage‐like porous structure makes the material superior over the 1D structure material (e.g., SBA‐15 or MCM‐41) in terms of mass transfer and diffusion of guest molecules, because it can lighten or avoid pore blockage by large‐sized particles during the loading process; thus, it may be a promising support for CO 2 methanation catalyst.…”

Synthesis and characterization of a novel organic–inorganic hybrid salt and its application as a highly effectual Brønsted–Lewis acidic catalyst for the production of N,N′‐alkylidene bisamides

“…[42] Solvent-free condition is a practical, well-known, useful, and green technique that has been used in organic synthesis; its advantages have been mentioned in the literature. [43][44][45] Considering the high significance of organicinorganic hybrid materials and N,N 0 -alkylidene bisamides, herein, a novel organic-inorganic hybrid salt, namely,…”

“…Solvent‐free condition is a practical, well‐known, useful, and green technique that has been used in organic synthesis; its advantages have been mentioned in the literature. [ 43–45 ]…”