Efficient Heterogeneous Catalyst For Synthesis Research Articles

ChemInform Abstract: Immobilized Palladium Nanoparticles on Silica—Starch Substrate (PNP—SSS): As a Stable and Efficient Heterogeneous Catalyst for Synthesis of p‐Teraryls Using Suzuki Reaction.

AbstractA variety of para‐, meta‐ and ortho‐teraryls is prepared in high yields under aqueous conditions from the corresponding benzene diiodides, dichlorides and dibromides.

ChemInform Abstract: Mesoporous AlPO4: A Highly Efficient Heterogeneous Catalyst for Synthesis of 5‐Substituted 1H‐Tetrazoles from Nitriles and Sodium Azide via [3 + 2] Cycloaddition.

AbstractMesoporous aluminum phosphate is described as possible candidate to substitute metal salts or other heterogeneous catalysts even in industrial applications.

Immobilized palladium nanoparticles on silica–starch substrate (PNP–SSS): As a stable and efficient heterogeneous catalyst for synthesis of p-teraryls using Suzuki reaction

Immobilized palladium nanoparticles on silica–starch substrate (PNP–SSS) were found to be an efficient reusable catalyst for excellent synthesis of teraryls using Suzuki reaction. The catalytic reactivity of PNP–SSS was examined over a set of substrates, demonstrating that it is reactive toward a variety of functionalities. In this process, the PNP–SSS catalyst can be reused more than six times with almost consistent efficiency and can be recovered by simple filtration.

Mesoporous AlPO4: A Highly Efficient Heterogeneous Catalyst for Synthesis of 5-Substituted 1H-Tetrazoles from Nitriles and Sodium Azide via [3 + 2] Cycloaddition

Abstract The mesoporous AlPO4 with high surface area and fine mesoporous structure was prepared by a soft template method and showed excellent catalytic performance for synthesis of 5-substituted 1H-tetrazoles from various nitriles and sodium azide with excellent yields (91%–98%). The heterogeneous AlPO4 catalyst is a good candidate to substitute metal salts or other heterogeneous catalyst and has potential value for industry application.

Phosphotungstic Acid Nanoclusters Grafted onto High Surface Area Hydrous Zirconia as Efficient Heterogeneous Catalyst for Synthesis of Octahydroquinazolinones and β-Acetamido Ketones

Phostungstic acid (PWA) nanoclusters grafted onto high surface area polycrystalline hydrous zirconia powder (PWA/ZrO2) was prepared by wet impregnation method. The zirconia particles were synthesized using a modified sol–gel route. The obtained material was characterized by X-ray diffraction (XRD), UV–Vis–diffuse reflectance spectroscopy (UV–Vis–NIR–DRS), infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and sorptometric techniques. XRD study revealed the presence of tetragonal phase of zirconia in the synthesized sample. TEM study indicates presence of small PWA clusters with size in the range of 5–15 nm well dispersed on the surface of the ZrO2 particles. The characteristic UV and IR absorption feature of the PWA was retained in the PWA/ZrO2 material. The PWA/ZrO2 material was used as an efficient catalyst for the preparation of octahydroquinazolinones and β-acetamido ketones. The octahydroquinazolinones were synthesized by the multicomponent condensation of dimedones, urea and aryl aldehydes in ethanol. Similarly, β-acetamido ketones were synthesized with high yield and purity by four component condensation of aryl aldehydes, enolizable ketones, and acetyl chlorides in acetonitrile. The protocols developed in this investigation using the PWA/ZrO2 catalyst is advantageous in terms of simple experimentation, high yield and purity of the products and recovery and reutilization of the heterogeneous catalyst.

B2O3/Al2O3 as a new, highly efficient and reusable heterogeneous catalyst for the selective synthesis of β-enamino ketones and esters under solvent-free conditions

Boron oxide adsorbed on alumina (B2O3/Al2O3 ) has been found to be a new and highly efficient heterogeneous catalyst for the synthesis of β-enamino ketones and esters by the enamination of various primary and secondary amines with β-dicarbonyl compounds under solvent-free conditions. The important features of this methodology are broad substrate scope, high yield, no requirement of metal catalysts, high regio- and chemoselectivity and environmental friendliness. In addition, the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity.

TiO2 nanoparticles: an efficient heterogeneous catalyst for synthesis of bis(indolyl)methanes under solvent-free conditions

Some bis(indolyl)methanes have been synthesized, in excellent yields, under solvent free conditions, by reaction of indoles with aromatic and aliphatic aldehydes in the presence of nano titanium(IV) oxide as an efficient, heterogeneous, reusable, and non-toxic catalyst.

HClO4-SiO2 and NaHSO4-SiO2: Two Efficient Heterogeneous Catalysts for Synthesis of N-Acylsulfonamides under Solvent-free Conditions

HClO4-SiO2 and NaHSO4-SiO2: Two Efficient Heterogeneous Catalysts for Synthesis of N-Acylsulfonamides under Solvent-free Conditions

Reusable Cobalt(III)‐Salen Complex Supported on Activated Carbon as an Efficient Heterogeneous Catalyst for Synthesis of 2‐Arylbenzimidazole Derivatives

AbstractVarious 2‐arylbenzimidazoles were synthesized from phenylenediamines and aromatic aldehydes via a one‐step process in the presence of a catalytic amount of a cobalt‐salen complex supported on activated carbon [CoxO‐Co(salen) 11] at room temperature. The salient features of this method include mild conditions, short reaction times, high yields, easy purification, recyclable catalyst, large‐scale synthesis and simple procedure. The reactions were performed in ethanol and the catalyst could be reused for several cycles without a decrease in activity. The heterogeneous catalyst was characterized by powder X‐ray diffraction (XRD), scanning electron microscopy (SEM), atomic forced microscopy (AFM), thermogravimetric (TG) methods for analysis of nitrogen adsorption and FT‐IR spectroscopy. Leaching experiments showed that the catalyst is most strongly anchored to the activated support after 10 cycles of reuse.

Synthesis of dimethyl carbonate by transesterification over CaO/carbon composites

A CaO/C composite, a new solid base catalyst, was prepared and served as a convenient and efficient heterogeneous catalyst for synthesis of DMC from methanol and propylene carbonate. Compared with pure CaO, the CaO/C shows the same basic properties and a high performance. In addition, the CaO/C catalyst, which is easily recovered, can be reused with little deactivation, if a suitable particle size is chosen.