Atom-economical synthesis of a high silica CHA zeolite using a solvent-free route

2015 ◽  
Vol 51 (95) ◽  
pp. 16920-16923 ◽  
Author(s):  
Xiong Wang ◽  
Qinming Wu ◽  
Chunyu Chen ◽  
Shuxiang Pan ◽  
Weiping Zhang ◽  
...  

A high silica CHA zeolite is successfully synthesized in the presence of a low-cost template of N,N,N-dimethylethylcyclohexylammonium bromide under solvent-free conditions.

2021 ◽  
Vol 18 ◽  
Author(s):  
Abolfazl Olyaei ◽  
Zahra Ghahremany ◽  
Madieh Sadeghpour

: A green and efficient protocol was developed for the one-pot three-component synthesis of novel 2-(4-hydroxy-2-oxo-2H-chromen-3-yl)-2-(arylamino)-1H-indene-1,3(2H)-dione derivatives by the reaction of 4-hydroxycoumarin, ninhydrin and aromatic amines in the presence of guanidine hydrochloride as an organocatalyst under solvent-free conditions. The present approach offers several advantages such as low cost, simple work-up, short reaction times, chromatography-free purification, high yields and greener conditions.


2013 ◽  
Vol 9 ◽  
pp. 2344-2353 ◽  
Author(s):  
Sudipta Pathak ◽  
Kamalesh Debnath ◽  
Animesh Pramanik

A convenient and efficient methodology for the synthesis of densely substituted pyrrole-fused isocoumarins, which employs solid-supported silica sulfuric acid (SSA) as catalyst, has been developed. When the mixture of ninhydrin adducts of acetylacetone/ethyl acetoacetate and primary amines was heated on the solid surface of SSA under solvent-free conditions, the pyrrole-fused isocoumarins were formed in good yields. This synthetic method has several advantages such as the employment of solvent-free reaction conditions without the use of any toxic reagents and metal catalysts, the ease of product isolation, the use of a recyclable catalyst, the low cost, the easy availability of the starting materials, and the excellent yields of products.


2011 ◽  
Vol 8 (4) ◽  
pp. 1626-1631 ◽  
Author(s):  
Liqiang Wu ◽  
Xiao Wang

An efficient solvent-free procedure for the preparation of 4,4′-epoxydicoumarins via the ondensation of 4-hydroxycoumarin with aldehydes in the presence of catalytic amount of phosphorus pentoxide/silica gel at 110°C is described. The advantages of this method are generality, high yields, short reaction times, ease of product isolation, low cost and ecologically friendly.


RSC Advances ◽  
2014 ◽  
Vol 4 (9) ◽  
pp. 4286-4291 ◽  
Author(s):  
Lingjun Li ◽  
Anlian Zhu ◽  
Yuqin Zhang ◽  
Xincui Fan ◽  
Guisheng Zhang

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Eskandar Kolvari ◽  
Maryam Mirzaeeyan

Al(NO3)3 · 9H2O efficiently catalyzes the three-component Biginelli reaction between an aldehyde, aβ-dicarbonyl compound, and urea or thiourea in refluxing ethanol and solvent-free (SF) conditions to afford the corresponding dihydropyrimidinones in high yields. The advantages of this method involve the easy procedure, the environmentally friendly process, and the low cost of the Lewis acid catalyst.


2019 ◽  
Vol 16 (7) ◽  
pp. 584-591 ◽  
Author(s):  
Hanan A. Soliman ◽  
Mahmoud El-Shahat ◽  
Abdel-Ghany Soliman

A straightforward strategy for the synthesis of N-sulfonyl imine derivatives from sulfonamides and aryl aldehydes utilizing Silica-supported zinc chloride (ZnCl2/SiO2, silzic) as a catalyst under solvent-free conditions has been developed. 2-Arylbenzothiazole derivatives were also synthesized by the reaction of 2-aminothiophenol with aryl aldehydes under the same conditions. This procedure has advantages of high yields, mild reaction condition, simple procedure, low cost, and simplicity of workup. The catalyst has the same efficiency on its reuse up to three times.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2975 ◽  
Author(s):  
Raquel Soengas ◽  
Yolanda Navarro ◽  
María Iglesias ◽  
Fernando López-Ortiz

A cycloaurated phosphinothioic amide gold(III) complex was supported on amorphous silica with the aid of an imidazolium ionic liquid (IL) physisorbed in the SiO2 pores (SiO2–IL) and covalently bonded to the SiO2 (SiO2@IL). Gold(0) nanoparticles (AuNPs) were formed in situ and subsequently immobilized on the SiO2–IL/SiO2@IL phase. The resulting catalytic systems Au–SiO2–IL and Au–SiO2@IL promoted the solvent-free A3 coupling reaction of alkynes, aldehydes, and amines in high yields under solvent-free conditions with very low catalyst loading and without the use of additives. The Au–SiO2@IL catalyst showed good recyclability and could be reused at least five times with yields of propargylamines of ≥80%. This synthetic method provides a green and low cost way to effectively prepare propargylamines. Additionally, 31P high resolution magic angle spinning (HRMAS) NMR spectroscopy is introduced as a simple technique to establish the Au loading of the catalyst.


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