Perlite: A cheap natural support for immobilization of sulfonic acid as a heterogeneous solid acid catalyst for the heterocyclic multicomponent reaction

An Efficient Synthesis of 3,4-dihydro-2(1H)-pyrimidinones from Aldehyde Bisulfite Adducts using Recyclable Wang Resin Supported Sulfonic Acid Catalyst

Abstract:

An efficient one-pot multicomponent synthesis of 3,4- dihydropyrimidin-2(1H)-ones has been developed from aldehyde bisulfite adducts, ethyl acetoacetate and urea using recyclable polymer- supported sulfonic acid catalyst. This new method provides several advantages over the previous synthesis, including high product yields, commercially viable, minimal workup operations and sustainable chemical practices.

Pd on the Composite of Perlite and Allylamine-N-isopropylacrylamide Copolymer: A Thermo-Responsive Catalyst for Hydrogenation of Nitroarenes under Mild Reaction Condition

A novel thermo-responsive catalyst for the hydrogenation of nitroarenes under mild reaction condition was devised. To prepare the catalyst, a thermo-responsive polymer was first synthesized through the co-polymerization of N-isopropylacrylamide and allylamine and then covalently grafted on the Cl-functionalized perlite. The resulting composite was subsequently utilized as a support for the stabilization of Pd nanoparticles. Investigation of the catalytic activity of the catalyst approved its high catalytic activity at a temperature above the lower critical solution temperature. More precisely, 0.03 g of the catalyst can promote the reaction of 1 mmol of nitro-compounds in H2O/EtOH (1:1) at 45 °C to furnish the corresponding products in 70–100% yields. This issue was assigned to the collapse of the polymeric component and formation of a hydrophobic environment that was beneficial for the mass-transfer of the hydrophobic nitroarenes. Notably, the catalytic activity of the catalyst was higher than that of palladated perlite and thermos-responsive polymer due to the synergistic effects between the perlite and polymeric moiety. Furthermore, the study of the substrate scope confirmed that a wide range of substrates with different steric and electronic properties could tolerate hydrogenation reaction. Moreover, the catalyst was highly selective toward hydrogenation of the nitro group and could be recycled up to seven runs with insignificant Pd leaching and loss of catalytic activity. The hot filtration test also confirmed the heterogeneous nature of the catalysis.

Recent Advancement in the One-Pot Synthesis of the Tri-Substituted Methanes (TRSMs) and Their Biological Applications

The history of tri-substituted methanes (TRSMs) in chemical industries is much older. Tri-substituted methanes were previously used as dyes in the chemical industries. Still, there is a significant surge in researchers' interest in them due to their wide range of bioactivities. Tri-substituted methane derivatives show a wide range of biological activities like anti-tumor, antimicrobial, antibiofilm, antioxidant, anti-inflammatory, anti-arthritic activities. Due to the wide range of medicinal applications shown by tri-substituted methanes, most of the methodologies reported in the literature for the synthesis of TRSMs are focused on the one-pot method. This review explored the recently reported one-pot processes for synthesizing tri-substituted methanes and their various medicinal applications. Based on the substitution attached to the -CH carbon, this review categorizes them into two major classes: (I) symmetrical and (II) unsymmetrical trisubstituted methanes. In addition, this review gives an insight into the growing opportunities for the construction of trisubstituted scaffolds via one-pot methodologies. To the best of our knowledge, no one has yet reported a review on the one-pot synthesis of TRSMs. Therefore, here we present a brief literature review of the synthesis of both symmetrical and unsymmetrical TRSMs covering various one-pot methodologies along with their medicinal applications.

A review on convenient synthesis of substituted coumarins using reuseable solid acid catalysts

Due to growing concern about chemicals and their impact on the environment, cleaner reaction conditions are needed to be incorporated into chemical synthetic procedures. Recently, the use of heteropolyacid catalysts, mainly reuseable solid acid catalysts, has gained a leading role in organic synthesis due to their environmental and economic considerations and industrial utilization. The high catalytic activity, moisture sensitivity, reusability and inexpensive makes solid supported reagents attractive substituents to conventional Lewis acids. Nowadays synthesis of coumarins and their derivatives has attracted considerable attention from organic and medicinal chemists for many years as a large number of natural products contain this heterocyclic nucleus. In continuation with our investigations into the synthesis of substituted coumarins and due to several advantages of heterogeneous catalysts viz. cost-effective, no side products, high yield of desired products and no toxic waste material, here we report a new approach for the synthesis of substituted coumarins using solid acid catalysts.

Experimental Investigations on the Performances of Composite Building Materials Based on Industrial Crops and Volcanic Rocks

Interdisciplinary and sustainability represent the main characteristics of this paper due to the fact that this research is offering a connection between two main areas—agronomy and construction, by using hemp shiv for the design of new building materials, which can increase the sustainability level of the building industry. For this reason, the main scope of this study is based on the investigation of a new category of composite building materials—lightweight mortars based on hemp shiv, volcanic rocks and white cement—which contribute to a positive environmental impact and help to increase indoor comfort. A complex report was carried out on two segments. The first one is focused upon the characteristics of the raw materials from the composition of the new materials, while the second segment presents a detailed analysis of these composites including morphological and chemical investigation, pyrolytic and fire behavior, compression and flexural strengths, and acoustic and thermal characteristics. The proposed recipes have as a variable volcanic rocks, while the hemp and the binder maintain their volumes and properties. The results were analyzed according to the influence of volcanic rocks on the new composites.

Continuous-Flow Process for Glycerol Conversion to Solketal Using a Brönsted Acid Functionalized Carbon-Based Catalyst

The acetalization of glycerol with acetone represents a strategy for its valorization into solketal as a fuel additive component. Thus, acid carbon-based structured catalyst (SO3H-C) has been prepared, characterized and tested in this reaction. The structured catalyst (L = 5 cm, d = 1 cm) showed a high surface density of acidic sites (2.9 mmol H+ g−1) and a high surface area. This catalyst is highly active and stable in the solketal reaction production in a batch reactor system and in a continuous downflow reactor, where several parameters were studied such as the variation of time of reaction, temperature, acetone/glycerol molar ratio (A/G) and weight hourly space velocity (WHSV). A complete glycerol conversion and 100% of solketal selectivity were achieved working in the continuous flow reactor equipped with distillation equipment when WHSV is 2.9 h−1, A/G = 8 at 57 °C in a co-solvent free operation. The catalyst maintained its activity under continuous flow even after 300 min of reaction.

Anchoring of triethanolamine-Cu(II) complex on magnetic carbon nanotube as a promising recyclable catalyst for the synthesis of 5-substituted 1H-tetrazoles from aldehydes

The development of heterogenization of copper nanoparticles on conductive supports is very challenging and has received much attention. Here, we synthesize a practical, efficient, and inexpensive heterogeneous catalyst to grow stable metallic copper(II) nanoparticles on the surface of magnetic carbon nanotube (Fe₃O₄-CNT) catalyst support physically functionalized with triethanolamine (TEA) that acts as a low-cost and non-toxic ligand to capture the copper nanoparticles [Fe₃O₄-CNT-TEA-Cu(II)]. The as-prepared heterogeneous catalyst was characterized by different techniques, such as Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, vibrating sample magnetometer, X-ray diffraction patterns, field-emission scanning electron microscopy, and atomic absorption spectroscopy analysis. The catalytic behavior of Fe₃O₄-CNT-TEA-Cu(II) was investigated in the preparation of 5-substituted 1H-tetrazole derivatives via one-pot, three-component reaction between aromatic aldehydes, hydroxylamine, and sodium azide. The low catalyst loading, wide substrate scope, use of inexpensive materials, simple separation of the catalyst from the reaction mixture by an external magnet, short reaction times, easy workup, affordability, and superb yield are some advantages of this protocol.

Cu(ii)-grafted SBA-15 functionalized S-methylisothiourea aminated epibromohydrin (SBA-15/E-SMTU-CuII): a novel and efficient heterogeneous mesoporous catalyst

The catalytic activity of novel synthesized SBA-15/E-SMTU-Cu^II nanocatalyst was investigated for the green, one-pot, pseudo five-component synthesis of tetrahydropyridine derivatives.

A unique opportunity for the utilization of glass wastes as a resource for catalytic applications: toward a cleaner environment

n-glass-waste-SO₃H at the service of catalytic application.

Novel synthesis of coumarin-containing secondary benzamide derivatives using tungstate sulfuric acid

A novel one-pot synthesis of coumarin-containing secondary benzamide derivatives is described using tungstate sulfuric acid as a reusable heterogeneous catalyst.

Nano-ZrO2 sulfuric acid: a heterogeneous solid acid nano catalyst for Biginelli reaction under solvent free conditions

Nano-ZrO₂ sulfuric acid [n-ZrO₂–SO₃H (n-ZrSA)] has been synthesized from the reaction of nano-ZrO₂ with chlorosulfonic acid as sulfonating agent.

A waste to wealth approach through utilization of nano-ceramic tile waste as an accessible and inexpensive solid support to produce a heterogeneous solid acid nanocatalyst: to kill three birds with one stone

Waste minimization through the utilization of cost-effective, available, and nontoxic nano-ceramic tile wastes for the heterogenization of sulfuric acid.

A new type of SO3H-functionalized magnetic-titania as a robust magnetically-recoverable solid acid nanocatalyst for multi-component reactions

This paper highlights a novel synthetic strategy for the preparation of robust and magnetically-recoverable solid acid nanocatalysts.

Magnetic nanoparticle-supported imidazole tribromide: a green, mild, recyclable and metal-free catalyst for the oxidation of sulfides to sulfoxides in the presence of aqueous hydrogen peroxide

Imidazole tribromide immobilized on magnetic nanoparticles as a bromine source was prepared and characterized by XRD, TGA, FT-IR, EDS, scanning and transmission electron microscopy, and vibrating sample magnetometer techniques.

Perlite: an inexpensive natural support for heterogenization of HBF4

Nano-perlite-fluoroboric acid (n-PeFBA) has been synthesized by immobilization of HBF₄ on perlite as a natural and cheap support to produce an efficient green heterogeneous reusable solid acid catalyst.

Catalytic performance of bismuth pyromanganate nanocatalyst for Biginelli reactions

Bi₂Mn₂O₇ nano-powders were synthesized via a stoichiometric 1 : 1 Bi : Mn molar ratio hydrothermal method at 180 °C for 48 h in a 1 M NaOH aqueous solution.

Expanded perlite: an inexpensive natural efficient heterogeneous catalyst for the green and highly accelerated solvent-free synthesis of 5-substituted-1H-tetrazoles using [bmim]N3 and nitriles

A versatile, green and highly accelerated protocol for preparing 5-substituted-1H-tetrazoles is reported using expanded perlite as a heterogeneous catalyst.