Halloysite Nanotubes Functionalized Sulfonic Acid: Synthesis, Spectroscopic Characterization, Computational Studies and Application for the Synthesis of 1,4-Dihydropyridines

2021 ◽  
Vol 18 ◽  
Author(s):  
Princy Gupta ◽  
Nayan Prakash ◽  
Yogeshwar Ramawat ◽  
Palvi Rajput ◽  
Amir Fayaz ◽  
...  

: Naturally occurring clay halloysite is used to synthesize novel halloysite functionalized sulfonic acid in two steps; functionalization followed by oxidation and its catalytic activity is estimated for one-pot synthesis of Hantzsch 1,4-dihydropyridines under green solvent-free conditions. Spectroscopic studies such as FTIR, TGA, elemental analysis and first-principles based quantum chemical studies are used to characterize the catalyst. Recyclability without significant loss of catalytic activity is observed for several runs.

2011 ◽  
Vol 65 (6) ◽  
Author(s):  
Xin-Bin Yang ◽  
Xiang-Kai Fu ◽  
Yu Huang ◽  
Ren-Quan Zeng

AbstractZirconium(IV) 4-sulphophenylethyliminobismethylphosphonate (ZSBEDP) was prepared and characterised by elemental analysis, IR, TG-DSC, and XRD. ZSBEDP was found to be an efficient catalyst for the Biginelli reaction of aromatic aldehyde, ethyl acetoacetate, and urea or thiourea under solvent-free conditions so as to give 3,4-dihydropyrimidones in good to excellent yields. The catalyst can be separated by simple filtration and reused without significant loss of its catalytic activity.


Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rabindranath Singha ◽  
Aminul Islam ◽  
Pranab Ghosh

AbstractA convenient and efficient solvent-free, facile, one-pot three-component graphene oxide catalysed approach has been described for the synthesis of chromeno-[4,3-b]quinolin-6-one derivatives from 4-hydroxycoumarin with aldehydes and aromatic amines. Graphene oxide (GO) has proved to be a new class of heterogeneous carbocatalyst which could be easily recovered and reused up to 5th run without significant loss of its catalytic activity. A broad scope of substrate applicability is offered and a plausible mechanism is also suggested for this developed protocol.


RSC Advances ◽  
2016 ◽  
Vol 6 (64) ◽  
pp. 59343-59351 ◽  
Author(s):  
M. Afradi ◽  
N. Foroughifar ◽  
H. Pasdar ◽  
H. Moghanian

Synthesis, characterization and utilization of the l-proline N-sulfonic acid-functionalized magnetic nanoparticles as a novel magnetically reusable acid catalyst for the synthesis of 3,4-dihydropyrimidine-2-[1H]thione derivatives is reported.


2009 ◽  
Vol 6 (s1) ◽  
pp. S390-S396 ◽  
Author(s):  
Abdolkarim Zare ◽  
Alireza Hasaninejad ◽  
Esmael Rostami ◽  
Ahmad Reza Moosavi-Zare ◽  
Maria Merajoddin ◽  
...  

A highly efficient, green and expeditious solvent-free method is described for the chemoselective conversion of aldehydes to the corresponding acylals in excellent yields, using acetic anhydride in the presence of catalytic amount (20 mol%) of silica-supported LiHSO4. Ketones does not react under these reaction conditions. LiHSO4/SiO2can be recovered and reused without any significant loss of its catalytic activity.


ChemInform ◽  
2015 ◽  
Vol 46 (11) ◽  
pp. no-no
Author(s):  
Moona Mohsenimehr ◽  
Manouchehr Mamaghani ◽  
Farhad Shirini ◽  
Mehdi Sheykhan ◽  
Fatemeh Azimian Moghaddam

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