Reusable Heterogeneous Lewis Acid Catalyst Research Articles

Ethyl-4-(aryl)-6-methyl-2-(oxo/thio)-3,4-dihydro-1H-pyrimidine-5-carboxylates: Silica supported bismuth(III)triflate catalyzed synthesis and antioxidant activity

Novel ethyl-4-(aryl)-6-methyl-2-(oxo/thio)-3,4-dihydro-1H-pyrimidine-5-carboxylates were synthesized from one-pot, three-component Biginelli reaction of aryl aldehydes, ethyl acetoacetate and urea/ thiourea by catalytic action of silica supported Bismuth(III) triflate, a Lewis acid. All the synthesized compounds were structurally characterized by spectral (IR, 1H NMR &13C NMR spectroscopic and Mass spectrometric) and elemental (C, H & N) analyses. The present protocol has deserved novel as, formed the products in high yields with short reaction times, involved eco-friendly methodology and reusable heterogeneous Lewis acid catalyst. The title compounds were screened for in vitro DPPH free radical scavenging antioxidant activity and identified 4i, 4j, 4h & 4f as potential antioxidants. The obtained in vitro results were correlated with molecular docking, ADMET, QSAR, Bioactivity & toxicity risk studies and molecular finger print properties and found that in silico binding affinities were identified in good correlation with in vitro antioxidant activity and studied the structure activity relationship. The molecular docking study has disclosed strong hydrogen bonding interactions of title compounds with aspartic acid (ASP197) aminoacid residue of 2HCK, a complex enzyme of haematopoietic cell kinase and quercetin. Results of toxicology study evaluated for potential risks of compounds have revealed title compounds as safer drugs. In ultimate the study has established ligand’s antioxidant potentiality as they effectively binds with ASP197 amino acid of Chain A hence confirms the inhibition of growth of reactive oxygen species in vivo. In addition, the title compounds have been identified as potential blood–brain barrier penetrable entities and efficient central nervous system (CNS) active neuro-protective antioxidant agents.

Synthesis of 2, 3-dihydroquinazolin-4(1H)-ones promoted by an efficient, inexpensive and reusable heterogeneous Lewis acid catalyst

Synthesis of 2, 3-dihydroquinazolin-4(1H)-ones promoted by an efficient, inexpensive and reusable heterogeneous Lewis acid catalyst

ChemInform Abstract: Polystyrene‐Supported GaCl3 as a Highly Efficient and Reusable Heterogeneous Lewis Acid Catalyst for the Three‐Component Synthesis of Benzoxanthene Derivatives.

AbstractA novel, general, mild, and eco‐friendly one‐pot method for the synthesis of the title compounds is presented including a simple work‐up procedure.

Polystyrene-supported GaCl3 as a highly efficient and reusable heterogeneous Lewis acid catalyst for the three-component synthesis of benzoxanthene derivatives

Naphthoquinone-based xanthenes, specifically 14-aryl-13H-dibenzo[a,i]xanthene-8,13(14H)-diones and 12-aryl-2,3,4,12-tetrahydro-1H-benzo[b]xanthene-1,6,11-triones, were obtained in good to excellent yields by a simple, mild, and efficient three-component coupling procedure utilizing polystyrene-supported gallium trichloride as a highly active and eco-friendly heterogeneous Lewis acid catalyst. This reaction was also extended to the preparation of 14-aryl-2-hydroxy-13H-dibenzo[a,i]xanthene-8,13(14H)-diones. The experimental and work-up procedure is very simple and the catalyst can be easily separated from the reaction mixture and reused several times in subsequent reactions.

ChemInform Abstract: Polystyrene‐Supported AlCl3 as a Highly Active and Reusable Heterogeneous Lewis Acid Catalyst for the One‐Pot Synthesis of Quinoxalines.

AbstractThe optimized conditions allow the preparation of the parent system (Va) and various functionalized derivatives for organic and drug synthesis.

An environmentally friendly, chemoselective, and efficient protocol for the preparation of coumarin derivatives by Pechman condensation reaction using new and reusable heterogeneous Lewis acid catalyst polystyrene-supported GaCl3

Abstract An environmentally benign Pechman protocol for the one-pot synthesis of 4-substituted coumarins through the condensation reactions of phenol substrates with β-ketoesters using polystyrene-supported GaCl 3 (PS–GaCl 3 ) as a highly active and reusable solid Lewis acid catalyst under mild and heterogeneous conditions in good to excellent yields is described. This new protocol is easy, simple, cost-effective, chemoselective, and in addition has the advantages of easy availability, stability, reusability and eco-friendly character of the catalyst, high to excellent yields, simple experimental and work-up procedure.

Polystyrene-supported GaCl3: A new, highly efficient and recyclable heterogeneous Lewis acid catalyst for acetylation and benzoylation of alcohols and phenols

Abstract A new, simple and highly chemoselective method for both acetylation and benzoylation of alcohols and phenols with acetic anhydride in the presence of polystyrene-supported gallium trichloride (PS/GaCl3) as a highly active and reusable heterogeneous Lewis acid catalyst is presented. In this catalytic system, primary, secondary and tertiary alcohols as well as phenols were converted to the corresponding acetates and benzoates with high yields. The heterogenized catalyst is of high reusability and stability in the acetylation reactions and was recovered several times with negligible loss in its activity or a negligible catalyst leaching, and also there is no need for regeneration. Remarkably, a selective mono-acetylation of symmetrical diols can be achieved chemoselectively by employing the same catalyst.

Polystyrene-supported GaCl3: A new, highly efficient and recyclable heterogeneous Lewis acid catalyst for tetrahydropyranylation of alcohols and phenols

A new, simple and highly chemoselective method for tetrahydropyranylation of alcohols and phenols with 3,4-dihydro-2H-pyran (DHP) in the presence of polystyrene-supported gallium trichloride (PS/GaCl3) as a highly active and reusable heterogeneous Lewis acid catalyst at room temperature is presented.

Polystyrene-supported GaCl3 as a highly efficient and recyclable heterogeneous Lewis acid catalyst for one-pot synthesis of N-substituted pyrroles

A new and environmentally benign method for the preparation of N-substituted pyrroles from one-pot condensation reaction of 2,5-hexanedione with amines and diamines in the presence of polystyrene-supported gallium trichloride (PS/GaCl3) as a highly active and reusable heterogeneous Lewis acid catalyst is presented. This new protocol has the advantages of easy availability, stability, reusability and eco-friendly of the catalyst, high to excellent yields, simple experimental and work-up procedure.

Polystyrene‐supported AlCl3 as a highly active and reusable heterogeneous lewis acid catalyst for the one‐pot synthesis of quinoxalines

AbstractA new and environmentally benign protocol for the synthesis of quinoxaline derivatives through the condensation reactions of 1,2‐diketones and 1,2‐phenylenediamines using cross‐linked polystyrene‐supported aluminum chloride (PS/AlCl3) as a highly active and reusable heterogeneous Lewis acid catalyst is described. This polymeric catalyst is stable and can be easily recovered and reused without appreciable change in its efficiency. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:472–477, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21039

Synthesis of arylaminotetrazoles by ZnCl2/AlCl3/silica as an efficient heterogeneous catalyst

Arylaminotetrazoles were efficiently synthesized from secondary arylcyanamides by application of ZnCl2/AlCl3/silica as a reusable heterogeneous Lewis acid catalyst. 5-Arylamino-1H-tetrazoles can be obtained from arylcyanamides carrying electron-withdrawing substituents on the aryl ring, while with electron-releasing groups 1-aryl-5-amino-1H-tetrazoles will be produced. The former isomer is also produced within longer reaction times (~20 h) even with electron-releasing groups.

ChemInform Abstract: One‐Pot Synthesis of N‐Substituted Pyrroles Catalyzed by Polystyrene‐Supported Aluminum Chloride as a Reusable Heterogeneous Lewis Acid Catalyst.

AbstractPolystyrene‐supported aluminum chloride is used as catalyst in Paal‐Knorr pyrrole synthesis for the first time.

One‐pot synthesis of N‐substituted pyrroles catalyzed by polystyrene‐supported aluminum chloride as a reusable heterogeneous lewis acid catalyst

AbstractA convenient and efficient procedure is presented for the one‐pot synthesis of N‐substituted pyrroles by condensation of 2,5‐hexandione and amines or diamines in the presence of cross‐linked polystyrene‐supported aluminum chloride (PS/AlCl3) as a highly active and reusable heterogeneous Lewis acid catalyst. This polymeric solid acid catalyst is stable and can be easily recovered and reused without appreciable change in its efficiency. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:85–90, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20661