Acid Catalyst For One-pot Synthesis Research Articles

Graphene Oxide Incorporated Strontium Nanoparticles as a Highly Efficient and Green Acid Catalyst for One-Pot Synthesis of Tetramethyl-9-aryl-hexahydroxanthenes and 13-Aryl-5H-dibenzo[b,i]xanthene-5,7,12,14(13H)-tetraones Under Solvent-Free Conditions

An efficient, inexpensive and recyclable graphene oxide/strontium nanocatalyst was synthesized and applied in a pseudo three-component, one-pot cyclocondensation of aromatic aldehydes and dimedone/lowson to afford the corresponding 3,3,6,6-tetramethyl-9-aryl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-diones and 13-aryl-5H-dibenzo[b,i]xanthene-5,7,12,14(13H)-tetraones in high yields under solvent-free conditions. To the best of our knowledge, there are no literature reports on applying graphene oxide/strontium as a nanocatalyst for xanthene derivatives synthesis. The key potential benefits of the present method are including high yields, short reaction time, easy workup, recyclability of catalyst and ability to tolerate a variety of functional groups which gives economical as well as ecological rewards. The nanocatalyst easily separated from the reaction mixture easily by applying an external magnet and reused at least six times without noticeable degradation in catalytic activity.

Effective preparation of amine-functionalized nano magnetite as a precursor of novel solid acid catalyst for one-pot synthesis of xanthenes under solvent-free conditions

Abstract In this work, a facile route was developed for the preparation of amine-functionalized magnetite nanoparticles by co-precipitation method. These amine-functionalized magnetite nanoparticles were sulfonated and then used as novel heterogeneous acid catalyst and their catalytic activities were investigated in the green synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes under thermal and solvent free conditions. The catalyst was characterized by FT-IR, SEM, EDX, XRD, TGA and VSM. Also, the catalyst could be recovered easily and reused several times without any significant loss of its catalytic activity.

N-Sulfonic acid poly(4-vinylpyridinium) hydrogen sulfate as an efficient and reusable solid acid catalyst for one-pot synthesis of xanthene derivatives in dry media under ultrasound irradiation

N-Sulfonic acid poly(4-vinylpyridinium) hydrogen sulfate catalyzed efficiently the synthesis of xanthene derivatives under ultrasonic irradiation at room temperature, which has prompted various concerns involving cost and environmental persistence. This methodology shows the effect of presence of anion hydrogen sulfate as an important and effective factor on the promotion of the one-pot multi-components and condensation reactions. The catalyst can be recovered by simple filtration and used for several times without a significant loss of catalytic activity.

Introduction of poly(4-vinylpyridinium) perchlorate as a new, efficient, and versatile solid acid catalyst for one-pot synthesis of substituted coumarins under ultrasonic irradiation

Poly(4-vinylpyridinium) perchlorate, is a supported, recyclable, eco-benign catalyst for synthesis of substituted coumarins via Pechmann reaction using ultrasound irradiation at room temperature and neat condition in high yields with short reaction times. The catalyst was studied by FT-IR, X-ray diffraction, scanning electron microscope, thermo-gravimetric and energy dispersion X-ray analyses. All the products were extensively characterized by 1H NMR, FT-IR, MS and melting point analyses. This methodology offers momentous improvements over various options for the synthesis of coumarins with regard to yield of products, simplicity in operation and green aspects by avoiding toxic catalysts and solvents. Further, the catalyst can be reused and recovered for several times without loss of activity.

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.

Xanthan sulfuric acid as an efficient, green, biodegradable, and recyclable solid acid catalyst for one-pot synthesis of N-substituted pyrroles under solvent-free conditions at room temperature

A new, green, and efficient method for synthesis of a variety of N-substituted pyrroles from condensation reactions of 2,5-hexanedione with amines or diamines using xanthan sulfuric acid as a biosupported and reusable ecofriendly catalyst under solvent-free conditions at room temperature is described. The use of a nontoxic, inexpensive, easily available, and reusable biosupported proton source catalyst under solvent-free conditions makes this protocol practical, environmentally friendly, and economically attractive.

Antimony(III) chloride impregnated on alumina — An efficient and economical Lewis acid catalyst for one-pot synthesis of dihydropyrimidinones under solvent-free conditions

The antimony(III) chloride impregnated on alumina efficiently catalyses a one-pot, three-component condensation reaction among an aldehyde, a β-ketoester, and urea or thiourea to afford the corresponding dihydropyrimidinones in good to excellent yields. The reactions are probed in microwave (MW), ultrasonic, and thermal conditions and the best results are found using MW under solvent-free conditions.Key words: Biginelli dihydropyrimidinones synthesis, SbCl3–Al2O3, MW, sonication, solid supported.