Reusable Heterogeneous Catalyst For Synthesis Research Articles

Fe3+-Montmorillonite K10 as an Efficient, Green and Reusable Heterogeneous Catalyst for Synthesis of Mannich Type Reaction under Solvent-free Condition

Fe3+-Montmorillonite K10 as an Efficient, Green and Reusable Heterogeneous Catalyst for Synthesis of Mannich Type Reaction under Solvent-free Condition

Quaternary-ammonium-immobilized polystyrenes as efficient and reusable heterogeneous catalysts for synthesis of cyclic carbonate: Effects of linking chains and pendent hydroxyl group

Spherical polystyrene-supported ammonium salts containing different linking chains between the support and ammonium groups were prepared as efficient and easily reusable heterogeneous catalysts for the cycloadditions of CO2 and epoxides. The effects of the length of the linking chains and a hydroxyl group pendent on the linking chain on the catalytic performance of ionic liquid immobilized catalysts and their mechanisms were studied through experiments and density functional theory calculations. It was found that, compared with a short linking chain, a long chain can make the halogen anion more negative and provide a larger contact area of the catalysts with the reactants, thus enhancing the reaction kinetics. The hydroxyl group can stretch the C–O bonds of the epoxides, promoting the reaction thermodynamics. As a result, for the cycloaddition of propylene oxide, the yield of propylene carbonate is much higher for the catalyst with a long linking chain (yield: 91.4%) compared with the yield for that with a short chain (yield: 70.9%), and is further increased in the presence of pendent hydroxyl groups (yield: 98.5%). The catalyst also shows a high catalytic activity even at mild temperature and good reusability (yield: ≥ 96% for 10 cycles), and the selectivity is always above 99%.

Ni–Al2O3 as reusable heterogeneous catalyst for expedient one-pot synthesis of naphthopyrans

Ni–Al2O3 is an efficient and reusable heterogeneous catalyst for the synthesis of naphthopyrans by one-pot three-component reaction of naphthols, aldehydes, and malononitrile in EtOH/H2O (1:1) solvent medium. A comparative study of Ni–Al2O3 with neutral Al2O3 revealed that reactions with the former afforded better product yields, indicating higher catalytic efficacy. Ni–Al2O3 due to its low cost, good activity, ease of handling, and easy recovery, with high yields and simple purification method makes the procedure highly applicable.

Bis-ammonium immobilized polystyrenes with co-catalyzing functional end groups as efficient and reusable heterogeneous catalysts for synthesis of cyclic carbonate from CO2 and epoxides

Novel bis-ammonium immobilized polystyrenes with co-catalyzing functional groups were prepared for efficient synthesis of cyclic carbonate from CO2 and epoxides.

ZnS nanoparticles as an efficient and reusable heterogeneous catalyst for synthesis of 1-substituted-1H-tetrazoles under solvent-free conditions

An efficient and green protocol for the synthesis of 1-substituted-1H-tetrazoles through cyclization reaction of various primary amines, sodium azide, and triethyl orthoformate was described. In this method, a series of tetrazole derivatives was synthesized by using ZnS nanoparticles as an effective, recoverable, and reusable catalyst under solvent-free conditions. This strategy is a magnificent improvement for the synthesis of these heterocycles due to the non-acidic, clean, and solvent-free conditions via a solid recyclable catalyst. The catalyst was separated by simple filtration and reused seven times without significant loss of activity. The ZnS nanoparticles with high surface area and fine monodisperse particles were prepared using the simple microwave-assisted method without using any surfactant. The ZnS nanoparticle catalyst is a good candidate to replace bronsted acids and metal salts or other catalyst for the preparation of 1-substituted-1H-tetrazoles in high yields and has potential values for industrial applications.

H-ferrierite zeolite: As an effective and reusable heterogeneous catalyst for synthesis of 1,5-benzothiazepine under solvent free condition and 1,3-dipolar cycloaddition in water

An efficient synthesis of new derivatives of 1,5-benzothiazepine has been developed by the reaction of various chalcones (1,3-diaryl-2-propenones) with 2-amino-thiophenol in the presence of H-ferrierite zeolite as acidic catalyst without solvent. In addition, 1,3-dipolar cycloaddition of hydrazonoyl chlorides on CN bond of 1,5-benzothiazepines in water in the presence of Na2CO3/THAC as a base catalyst afforded 1,2,4-triazolo[3,4-d][1,5]benzothiazepines. The structure of all the newly synthesized compounds was established on the basis of spectral data (Mass, IR, 1H NMR, 13C NMR) and elemental analysis.

Alumina supported MoO3: An efficient and reusable heterogeneous catalyst for synthesis of 3,4-dihydropyridine-2(1H)-ones under solvent free conditions

Abstract An efficient solvent free method for the synthesis of various 3,4-dihydropyrimidin-2(1 H )-ones in excellent yields using alumina-supported MoO 3 as recyclable heterogeneous catalyst is described. Compared to known methods, this new method provides an easy access to various 3,4-dihydropyrimidin-2(1 H )-ones in excellent yields with shorter reaction times. Further the catalyst could be easily recovered from reaction mixture by filtration and is reusable.