ChemInform Abstract: HClO4-SiO2and NaHSO4-SiO2: Two Efficient Heterogeneous Catalysts for Synthesis of N-Acylsulfonamides under Solvent-Free Conditions.

ChemInform ◽  
2009 ◽  
Vol 40 (34) ◽  
Author(s):  
Liqiang Wu ◽  
Chunguang Yang ◽  
Chong Zhang ◽  
Liming Yang
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Mouhsine Laayati ◽  
Ali Hasnaoui ◽  
Nayad Abdallah ◽  
Saadia Oubaassine ◽  
Lahcen Fkhar ◽  
...  

Magnetically separable strontium hexaferrite SrFe12O19 was prepared using the chemical coprecipitation method, and the nanostructured material was characterized by X-ray diffraction, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and BET analysis. The SEM images showed the homogeneity of the chemical composition of SrFe12O19 and uniform distribution of size and morphology. The pore size of the nanomaterial and its specific area were determined by BET measurements. Strontium hexaferrite SrFe12O19 exhibited a strong magnetic field, which is highly suitable in the heterogeneous catalysis as it can be efficiently separated from the reaction. The magnetic nanocatalyst showed high activity and environmentally benign heterogeneous catalysts for the epoxide ring-opening with amines affording β-amino alcohols under solvent-free conditions. When unsymmetrical epoxides were treated in the presence of aromatics amines, the regioselectivity was influenced by the electronic and steric factors. Total regioselectivity was observed for the reactions performed with aliphatic amines. The magnetically SrFe12O19 nanocatalyst showed excellent recyclability with continuously good catalytic activities after four cycles.


RSC Advances ◽  
2014 ◽  
Vol 4 (90) ◽  
pp. 49462-49470 ◽  
Author(s):  
Ganga Ram Chaudhary ◽  
Pratibha Bansal ◽  
Navneet Kaur ◽  
S. K. Mehta

CuO nanoparticles synthesized via a cost-effective and greener-approach. CuO Nanoparticles were used for the first time as catalysts in the synthesis of xanthenes and proved to be efficient when compared to other catalysts.


Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 90
Author(s):  
Anup Paul ◽  
Anirban Karmakar ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro

The new 1D CPs [Zn(L1)(H2O)4]n.nH2O (1) and [Zn(L2)(H2O)2]n (2) [L1 = 1,1′-(ethane-1,2-diyl)bis(6-oxo-1,6-dihydropyridine-3-carboxylic acid); L2 = 1,1′-(propane-1,3-diyl)bis(6-oxo-1,6-dihydropyridine-3-carboxylic acid)] were prepared from flexible dicarboxylate pro-ligands (H2L1 and H2L2). Both CPs 1 and 2 were characterized by elemental, FTIR, and powder X-ray diffraction analysis. Their geometry and the structural features were unveiled by single-crystal X-ray diffraction analysis. The underlying topology of the CPs was illustrated by the topological analysis of the H-bonded structure of CP 1, which revealed a 3,4,6-connected trinodal net. On the other hand, topological analysis on the hydrogen-bonded network of CP 2 showed a 2,3,3,4,6,7-connected hexanodal net. The thermal stability of the CPs was investigated by thermogravimetric analysis. CPs 1 and 2 act as heterogeneous catalysts in one-pot tandem deacetalization–Knoevenagel condensation reactions under environmentally mild conditions. CPs 1 exhibits a yield of ca. 91% in a microwave-assisted solvent-free medium, whereas a slightly lower yield was obtained for CP 2 (87%) under the same experimental protocol. The recyclability of catalyst 1 was also assessed. To our knowledge, these are the first Zn(II)-based CPs to be applied as heterogeneous catalysts for the above tandem reactions under environmentally friendly conditions.


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