Direct benzylation of 1,3-dicarbonyl compounds catalyzed by Cs2.5H0.5PW12O40 in solvent-free conditions

2011 ◽  
Vol 89 (12) ◽  
pp. 1533-1538 ◽  
Author(s):  
Ezzat Rafiee ◽  
Maryam Khodayari ◽  
Mohammad Joshaghani

Various 1,3-dicarbonyl compounds reacted readily with benzylic alcohols in the presence of Cs2.5H0.5PW12O40 salt to produce 2-benzylic-1,3-dicarbonyl compounds in high yields. It was found that this catalyst could be completely recovered and reused without loss of its catalytic activities and is thus environmentally conscious especially in solvent-free conditions. The use of this method provides improved modification of the direct benzylation of 1,3-carbonyl compounds in terms of low reaction times, solvent-free conditions, usage of a small amount of the catalyst, and a clean reaction profile. Furthermore, the use of this catalyst is feasible because of its easy preparation, its easy handling, its stability, its easy recovery, its reusability, being environmentally green, its excellent activity, and its selectivity.

2021 ◽  
Vol 76 (2) ◽  
pp. 85-90
Author(s):  
Abdolkarim Zare ◽  
Manije Dianat

Abstract A highly efficient and green protocol for the synthesis of pyrimido[4,5-b]quinolines has been described. The one-pot multicomponent reaction of dimedone with arylaldehydes and 6-amino-1,3-dimethyluracil in the presence of N,N-diethyl-N-sulfoethanaminium chloride ([Et3N–SO3H][Cl]) as an ionic liquid (IL) catalyst under solvent-free conditions afforded the mentioned compounds in high yields and short reaction times. Our protocol is superior to many of the reported protocols in terms of two or more of these factors: the reaction times, yields, conditions (solvent-free versus usage of organic solvents), temperature and catalyst amount.


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.


2018 ◽  
Vol 42 (12) ◽  
pp. 604-607
Author(s):  
Loghman Firoozpour ◽  
Hoda Yahyavi ◽  
Ramona Ejtemaei ◽  
Setareh Moghimi ◽  
Alireza Foroumadi

A green and efficient method for preparing novel heterocyclic systems is established through the reaction of differently substituted benzaldehydes, barbituric acid and 4-amino-2H-chromene-2-one under solvent-free conditions. This method affords 6H-chromeno[3’,4’:5,6] pyrido[2,3-d]pyrimidine-trione derivatives in high yields and short reaction times.


2009 ◽  
Vol 63 (1) ◽  
Author(s):  
Mohammad Abdollahi-Alibeik ◽  
Zahra Zaghaghi

AbstractEfficient syntheses of 3,4-dihydropyrimidin-2-(1H)-ones and the corresponding thioxo derivatives using 1,3-dibromo-5,5-dimethylhydantoin (DBH) catalysis of a one-pot three-component Biginelli reaction of aldehydes, ethyl acetoacetate, and urea or thiourea under microwave irradiation are described. The advantages of this method are its short reaction times, high yields of the products, inexpensive and commercially available catalyst, and solvent-free conditions. Typical isolated yields exceed 70 % for arylaldehydes (9 examples) and aliphatic aldehydes (2 examples).


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.


2018 ◽  
Vol 21 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Omid Marvi ◽  
Leila Zare Fekri

Aim and Objective: Citrus Juice as an efficient, cost-effective and green catalyst employed for one-pot synthesis of various β-substituted enaminones through the reaction of β- dicarbonyl compounds with different primary amines in a solvent-free conditions on silica gel as solid surface using grindstone technique in high yields and short reaction times. The presented procedure is operationally simple, practical and green. Material and Methods: The wide application of this procedure is demonstrated by the use of various substituted amines to react with β-dicarbonyl compounds. The method was successfully applied for primary amines (15 entries) and the related enaminones were well synthesized in good to excellent yields. Melting points were measured on an Electro thermal 9100 apparatus. 1HNMR and 13C NMR spectra were recorded on a FTNMR BRUKER DRX 500 Avence spectrometer. Chemical shifts were given in ppm from TMS as internal references and CDCl3 was used as the solvent as well. The IR spectra were recorded on a Perkin Elmer FT-IR GX instrument. The chemicals used in this work were purchased from Merck and Fluka chemical companies. Results: Grinding synthesis of citrus juice catalyzed enamination of 1,3-dicarbonyls (acetylacetone, methyl and ethyl- 3-oxobutanoate) with various primary amines ( aromatic and aliphatic) under solvent-free silica supported conditions was examined and studied (15 entries) and the obtained enaminones were well synthesized in good to excellent yields. Furthermore, the effect of various catalysts on the yield and reaction time for grinding synthesis of 3-phenylamino- but- 2- enoic acid ethyl ester (1) by this method has evaluated as well. Conclusion: a novel, efficient and green protocol for the grinding synthesis of enaminones using citrus juice as natural catalyst has been presented. This methodology is user friendly, green and low cost procedure under mild reaction condition with faster reaction rates. The citrus juice is inexpensive and non-toxic which makes the process convenient, more economic and benign. Furthermore, applying grindstone technique in solvent-free conditions, use of silica gel as a solid and heterogeneous surface in reaction, high yields of products, cleaner reaction profiles, and availability of the reagents makes this method a better choice for synthetic chemists.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Zahed Karimi-Jaberi ◽  
Marziyeh Jokar ◽  
S. Zoleykha Abbasi

Two efficient and direct procedures have been developed for the preparation of 1-amidoalkyl-2-naphthols by a one-pot condensation of aldehydes, 2-naphthol, and amides in the presence of trichloroacetic acid or cobalt (II) chloride as catalyst. The reactions were carried out under solvent-free media. High yields, short reaction times, easy workup of the catalyst are advantages of these procedures.


2012 ◽  
Vol 9 (4) ◽  
pp. 2037-2043 ◽  
Author(s):  
Abolghasem Davoodnia ◽  
Bahareh Razavi ◽  
Niloofar Tavakoli-Hoseini

Silica gel-supported polyphosphoric acid (PPA-SiO2) was found to be highly efficient, eco-friendly and recyclable heterogeneous catalyst for the synthesis of 2,4,6-triarylpyridines through one-pot three-component reaction of acetophenone, aryl aldehydes, and ammonium acetate under solvent-free conditions. This method has several advantages, such as simple procedure with an easy work-up, short reaction times, and high yields. Furthermore, the catalyst could be recycled after a simple work-up, and used at least three times without substantial reduction in its catalytic activity.


2010 ◽  
Vol 63 (1) ◽  
pp. 135 ◽  
Author(s):  
Anil Kumar ◽  
M. Sudershan Rao ◽  
V. Kameshwara Rao

A simple and efficient chemoselective thioacetalization of carbonyl compounds has been achieved using Ce(OTf)3 (10 mol-%) as a catalyst under solvent-free conditions. Advantages of the methodology include very short reaction times, excellent yields, the catalytic use of a water tolerant Lewis acid, and simple recovery and reuse of the catalyst.


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