scholarly journals Polystyrene-supported aluminum chloride as an efficient and reusable catalyst for condensation of indole with various carbonyl compounds

2010 ◽  
Vol 75 (4) ◽  
pp. 423-431 ◽  
Author(s):  
Bahman Tamami ◽  
Nasrolahi Shirazi ◽  
Parvanak Borujeni

Crosslinked polystyrene-supported aluminum chloride (Ps-AlCl3) is a stable, recyclable and environmental friendly heterogeneous catalyst for the condensation of indole with aldehydes and ketones to afford bis-indolylmethanes. In addition, (Ps-AlCl3) shows satisfactory selectivity in the reaction of mixtures of an aldehyde and a ketone with indole. Although AlCl3 is a water sensitive, corrosive and environmentally harmful compound, Ps-AlCl3 is a stable and water-tolerant species. The mild reaction conditions, short reaction times, easy work-up, high to excellent yields, chemoselectivity, reuse of the catalyst for at least ten times without significant change in its catalytic activity, low cost, and easy preparation and handling of the polymeric catalyst are obvious advantages of the present method.

2007 ◽  
Vol 85 (6) ◽  
pp. 416-420 ◽  
Author(s):  
Alireza Hasaninejad ◽  
Abdolkarim Zare ◽  
Hashem Sharghi ◽  
Mohsen Shekouhy ◽  
Reza Khalifeh ◽  
...  

A simple and efficient solvent-free procedure for the preparation of bis(indolyl)methanes via electrophilic substitution reactions of indoles with aldehydes and ketones is described. The reactions took place in the presence of a catalytic amount of silica chloride at room temperature. The advantages of this method are high yields, short reaction times, low cost, and compliance with green-chemistry protocols.Key words: silica chloride, indole, carbonyl compound, solvent-free, bis(indolyl)methane.


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.


2021 ◽  
Author(s):  
Anurag Kumar ◽  
Yifat Harel ◽  
Jean-paul Lellouche ◽  
Suman L. Jain

Abstract Owing to their inherent features like smaller size and higher surface area exposed to reactants, nanoparticles have gained enormous interest and are extensively used as magnetically recyclable catalysts for various organic reactions. Herein, we report highly hydrophilic, non-aggregated, and strongly positively charged (ζ potential: +45.7 mV) ultra-small cerium cations/complexes- stabilized maghemite nanoparticles in water as an efficient and reusable nanoscaled magnetically active catalyst for the nucleophilic addition reaction of various amines with α,β-unsaturated carbonyl compounds to give corresponding β-amino derivatives under ultrasonic irradiation. The developed protocol provides several merits such as high product yields, mild reaction conditions, reusable catalyst and easy workup.


2010 ◽  
Vol 8 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Kiran Shelke ◽  
Suryakant Sapkal ◽  
Kirti Niralwad ◽  
Bapurao Shingate ◽  
Murlidhar Shingare

AbstractA green, mild and efficient method for Knoevenagel condensation of 3-formylchromone/2-chlroquinoline-3-carbaldehyde with active methylene compounds such as Meldrum’s acid/ethyl cyanoacetate using biosupported cellulose sulphuric acid (CSA) in the solid-state by grinding under solvent-free condition has been developed. This method provides several advantages including environmental friendliness, shor t reaction times, high yields and a simple work-up procedure. Moreover, the CSA was successfully reused for four cycles without significant loss of activity.


2018 ◽  
Vol 7 (3) ◽  
pp. 22 ◽  
Author(s):  
Massimo Pitorri ◽  
Marco Franceschin ◽  
Ilaria Serafini ◽  
Alessandro Ciccòla ◽  
Claudio Frezza ◽  
...  

This paper reports on the modification of two synthetic steps in the usual protocol used for obtaining EMICORON. EMICORON is a benzo[ghi]perylen-diimide, which was synthesized for the first time in our laboratory in 2012, and has shown to have in vivo antitumor activities that interferes with the tumor growth and development using a multi-target mechanism of action. The provided modifications, which involved the reaction times, the reaction conditions, and the work-up procedures, allowed the global yield of the process to be increased from 28% to about 40%. Thus, this new procedure may be more suitable for recovering higher amounts of EMICORON to be used in further preclinical studies.


2015 ◽  
Vol 69 (3) ◽  
Author(s):  
Hamed Rouhi-Saadabad ◽  
Batool Akhlaghinia

AbstractAn efficient mixed reagent for direct synthesis of symmetrical carboxylic anhydrides from carboxylic acids has been prepared. Carboxylic acids are converted to anhydrides using triphenylphosphine/ trichloroisocyanuric acid under mild reaction conditions at room temperature. Short reaction time, excellent yields of products, low cost, availability of reagents, simple experimental procedure, and easy work-up of the products are the main advantages of the presented method.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Yuliang Zhang ◽  
Zhongqiang Zhou

A simple and efficient synthesis of 5-arylidene-2,4-thiazolidinediones by the Knoevenagel condensation of aromatic aldehydes with 2,4-thiazolidinedione catalyzed by ethylenediamine diacetate under solvent-free conditions is described. The major advantages of this method are simple experimental and work-up procedures, solvent-free reaction conditions, small amount of catalyst, short reaction time, high yields, and utilization of an inexpensive and reusable catalyst.


2008 ◽  
Vol 86 (8) ◽  
pp. 831-840 ◽  
Author(s):  
Iraj Mohammadpoor-Baltork ◽  
Majid Moghadam ◽  
Shahram Tangestaninejad ◽  
Valiollah Mirkhani ◽  
Arsalan Mirjafari

Different types of primary and secondary alcohols were efficiently transformed to their corresponding methoxymethyl (MOM) and ethoxymethyl (EOM) ethers in the presence of catalytic amounts of H3PW12O40 at room temperature under solvent-free conditions. Selective protection of primary and secondary alcohols in the presence of phenols and tertiary alcohols was achieved by this method. Deprotection of these ethers to their parent alcohols was also performed using this catalyst in ethanol under reflux conditions. We have also found that primary and secondary MOM- and EOM-ethers are selectively deprotected in the presence of phenolic and tertiary ones, methyl and benzyl ethers, esters, and trimethylsilyl ethers by this catalyst. The notable advantages of this protocol are high yields, short reaction times, easy work-up, non-toxicity, easy availability and handling, eco-friendly, and reusability of the catalyst.Key words: methoxymethylation, ethoxymethylation, protection, deprotection, heteropoly acid.


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 62 (1) ◽  
Author(s):  
Jabbar Khalafy ◽  
Ramin Javahershenas

<p>A green approach for the synthesis of polyfunctionalized pyrrolo[2,3-<em>d</em>]pyrimidine derivatives was successfully achieved by a one-pot, three-component reaction of arylglyoxals, 6-amino-1,3-dimethyluracil and barbituric acid derivatives in the presence of tetra-<em>n</em>-butylammonium bromide (TBAB) (5 mol%) as the catalyst in ethanol at 50 °C. This protocol has many advantages such as high yields (73-95%), green and simple procedure, short reaction times, easy work-up, mild reaction conditions and general applicability.</p>


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