Copper nanoparticles supported on 2‐methoxy‐1‐phenylethanone‐functionalized MCM‐41: An efficient and recyclable catalyst for one‐pot three‐component C–S coupling reaction of aryl halides with benzyl bromide and thiourea

An environmentally friendly copper‐based catalyst supported on 2‐methoxy‐1‐phenylethanone‐functionalized MCM‐41 was prepared and characterized by Fourier transform‐infrared, transmission electron microscopy, field emission‐scanning electron microscopy, X‐ray diffraction and inductively coupled plasma techniques. The catalyst was applied for the one‐pot three‐component C–S coupling reactions of aryl halides with benzyl bromide and thiourea under aerobic conditions to afford the corresponding coupled products in good yields in water. The catalyst could be recovered and recycled five times. These results prove 2‐methoxy‐1‐phenylethanone‐functionalized MCM‐41 supported Cu (II) complex was not leached during the reaction. Also it shows the correct heterogeneous nature of the catalyst.     

A phosphine‐free heterogeneous Suzuki–Miyaura reaction of aryl bromides catalyzed by MCM‐41‐supported tridentate nitrogen palladium complex under air

MCM‐41‐supported tridentate nitrogen palladium(II) complex [MCM‐41‐3 N‐Pd(II)] was conveniently synthesized from commercially available and cheap 3‐(2‐aminoethylamino)propyltrimethoxysilane via immobilization on MCM‐41, followed by reacting with pyridine‐2‐carboxaldehyde and PdCl₂. It was found that this palladium complex is an excellent catalyst for the Suzuki–Miyaura coupling reaction of aryl bromides on two points: (i) the use of 5 × 10⁻⁴ mol equiv. of MCM‐41‐3 N‐Pd(II) under air afforded the coupling products efficiently after easy workup; (2) the catalyst can be reused many times without loss of catalytic activity. Copyright © 2011 John Wiley & Sons, Ltd.     

Palladium 2‐mercapto‐N‐propylacetamide complex anchored onto MCM‐41 as efficient and reusable nanocatalyst for Suzuki,Stille and Heck reactions and amination of aryl halides

A palladium 2‐mercapto‐N‐propylacetamide complex supported on functionalized MCM‐41 was prepared by a post‐grafting method and considered as an efficient catalyst for C? C cross‐coupling reactions between various aryl halides and sodium tetraphenylborate, phenylboronic acid, triphenyltin chloride or alkenes. Also, this catalyst shows good reactivity towards amination of aryl halides. This nanocatalyst was characterized using thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, inductively coupled plasma and transmission electron microscopy techniques. Further results indicated that the heterogeneous catalyst could be recovered easily and reused several times without any loss of its catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.     

Copper(I)‐N2S2‐salen type complex covalently anchored onto MCM‐41 silica: an efficient and reusable catalyst for the A3‐coupling reaction toward propargylamines

The immobilization of copper complexes by covalent anchoring of the ligand on the surface of mesoporous MCM‐41 has been described. Bis[2‐(phenylthio)benzylidene]‐1,2‐ethylenediamine as a new N₂S₂ donor salen‐type ligand was covalently anchored onto nanopores of MCM‐41 coordinated with copper (I) halide. The organic–inorganic hybrid material was achieved readily using 3‐mercaptopropyltrimethoxysilane as a reactive surface modifier. 2‐Nitrobenzaldehyde was reacted smoothly with the thiol moieties in order to form functionalized nanoporous silica with carbaldehyde groups. The resulting supported organic moieties were converted to thiosalen ligand and coordinated with CuX (X = CN, Cl, Br, I). Characterization of the heterogeneous catalyst by X‐ray diffraction, N₂ sorption, FT‐IR, diffuse reflectance UV‐visible and TGA techniques indicated successful grafting of the copper complex inside the nano‐channels of MCM‐41. The heterogenized catalyst was evaluated by the Mannich condensation reaction of aldehydes, amines and alkynes. In this reaction, the corresponding propargylamines were obtained as single products in good to excellent yields. Factors such as reaction temperature, solvent, catalyst loading, leaching and reusability of the catalyst also were discussed. The use of MCM‐41 as support permits an easier separation and recycles with only a marginal decrease in reactivity. Copyright © 2013 John Wiley & Sons, Ltd.     

A highly efficient heterogeneous rhodium(I)‐catalyzed C–S coupling reaction of thiols with polychloroalkanes or alkyl halides under mild conditions

Heterogeneous C–S coupling reaction of thiols with polychloroalkanes or alkyl halides was achieved at 30 or 80 °C in the presence of 5 mol% of an MCM‐41‐immobilized bidentate phosphine rhodium complex (MCM‐41‐2P‐RhCl(PPh₃)) and triethylamine, yielding a variety of formaldehyde dithioacetals, ethylenedithioethers and unsymmetric thioethers in good to excellent yields. This heterogeneous rhodium catalyst can be easily recovered and recycled by simple filtration of the reaction solution and used for at least 10 consecutive trials without significant loss of activity. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis of Spiro‐dihydrofuran in the Presence of a Novel and Reusable Nanocatalyst Cu (II)‐Glycerol/MCM‐41

The use of supported Cu complex on mesoporous as a novel, efficient, heterogeneous, reusable and green catalyst for the synthesis of spiro‐dihydrofuran derivatives is reported. This methodology is effective for the reaction of dimedone with a wide range of aldehyde in the presence of BrCN and triethylamine. The structure of catalyst was characterized by different techniques such as EDX, SEM, TGA, ICP‐OES, XRD, TEM, FT‐IR, and BET. The recycled nanocatalyst was used at least five times with no significant loss of its activity.     

Oxo‐vanadium(IV) Schiff base complex supported on modified MCM‐41: a reusable and efficient catalyst for the oxidation of sulfides and oxidative S–S coupling of thiols

Oxo‐vanadium(IV) Schiff base complex supported on MCM‐41 as an organic–inorganic hybrid heterogeneous catalyst was synthesized with post‐grafting of MCM‐41 with 3‐aminoropropyltrimethoxysilane and subsequent reaction with 3,4‐dihydroxybenzaldehyde and then complexation with oxo‐vanadium acetylacetonate salt. The catalyst was analysed using a series of characterization techniques such as Fourier transform infrared spectroscopy, small‐angle X‐ray diffraction, nitrogen absorption isotherm, transmission electron microscopy and thermogravimetric analysis. The data collected provided evidence that the vanadium complex was anchored onto MCM‐41. High catalytic activity of this catalyst was observed in the oxidation of various sulfides and thiols (into sulfoxides and disulfides, respectively) with urea hydrogen peroxide as oxidant in high to excellent yields and selectivity under mild conditions. The heterogeneous catalyst could be recovered easily and reused several times without significant loss in catalytic activity and selectivity. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis and characterization of MCM‐41‐Biurea‐Pd as a heterogeneous nanocatalyst and using its catalytic efficacy in C–C,C–N and C–O coupling reactions

MCM‐41‐Biurea‐Pd is introduced as a new, heterogeneous and reusable catalyst for C–C and C–heteroatom bond formation between various aryl halides, phenols and amines, in the presence of Ph₃SnCl (Stille reaction) in PEG‐400 as a green solvent at room temperature. The structure of the functionalized MCM‐41 was analysed using various techniques.     

A novel and highly efficient polyaniline‐functionalized multiwall carbon nanotube‐supported cu(I) complex for Sonogashira coupling reactions of aryl halides with phenylacetylene

A polyaniline‐functionalized multiwall carbon nanotube‐supported Cu(I) complex was developed as an efficient catalyst for the Sonogashira reactions of aryl halides with phenylacetylene in the presence of potassium hydroxide in dimethylformamide at 135 °C under nitrogen atmosphere. The corresponding products were generated in good to excellent yields using this catalytic system. Moreover, the multiwall carbon nanotube‐supported Cu(I) catalyst was simply recycled and reused for six consecutive runs.     

MCM‐41‐supported mercapto palladium(0) complex: an efficient and recyclable catalyst for the heterogeneous Stille coupling reaction

The Stille cross‐coupling reaction of organostannanes with aryl halides was achieved in the presence of a catalytic amount of MCM‐41‐supported mercapto palladium(0) complex (1 mol%) in DMF? H₂O (9:1) under air atmosphere in good to high yields. This MCM‐41‐supported palladium catalyst can be reused at least 10 times without any decrease in activity. Copyright © 2009 John Wiley & Sons, Ltd.     

Immobilization of cerium (IV) and erbium (III) in mesoporous MCM‐41: Two novel and highly active heterogeneous catalysts for the synthesis of 5‐substituted tetrazoles,and chemo‐ and homoselective oxidation of sulfides

Two well‐ordered 2D ‐ hexagonal cerium (IV) and erbium (III) embedded functionalized mesoporous MCM ‐ 41(MCM‐41@Serine/Ce and MCM ‐ 41@Serine/Er) have been developed via functionalization of mesoporous MCM ‐ 41. The surface modification method has been used in the preparation of serine‐grafted MCM ‐ 41 and led to the development of MCM‐41@Serine. The reaction of MCM‐41@Serine with Ce (NH₄)₂(NO₃)₆·2H₂O or ErCl₃·6H₂O in ethanol under reflux led to the organization of MCM‐41@Serine/Ce and MCM‐41@Serine/Er catalysts. The structures of these catalysts were determined using scanning electron microscopy, mapping, energy‐dispersive X‐ray spectroscopy, Fourier transform‐infrared, thermogravimetric analysis, X‐ray diffraction, inductively coupled plasma, and Brunauer–Emmett–Teller analysis. These MCM‐41@Serine/Ce and MCM‐41@Serine/Er catalysts show outstanding catalytic performance in sulfides oxidation and synthesis of 5‐substituted tetrazoles. These catalysts can be recycled for seven repeated reaction runs without showing a considerable decrease in catalytic performance.     

一种经MCM-41负载双齿膦钯(0)配合物催化的羰基化Suzuki偶联合成二芳酮的新途径

在催化量的MCM-41负载双齿膦钯(0)配合物存在下,芳基碘化物和芳基硼酸、一氧化碳在常压下能顺利进行羰基化Suzuki偶联反应,高产率地生成了各种二芳酮化合物。MCM-41负载双齿膦钯(0)配合物具有比PdCl2(PPh3)2 更高的活性和选择性,且可回收再用10次其活性基本不变,为各种功能化二芳酮的合成提供了方便实用的新途径。     

Palladium chloride anchored on organic functionalized MCM‐41 as a catalyst for the Heck reaction

Palladium chloride was grafted to amino‐functionalized MCM‐41 to prepare heterogeneous catalysts. XRD, N₂ adsorption–desorption isotherms, IR, ¹³C and ²⁹Si cross‐polarization magic‐angle spinning NMR spectroscopy and XPS techniques were employed to characterize the catalytic materials. The heterogeneous palladium catalyst exhibited excellent catalytic activity for the Heck vinylation of iodobenzene with methyl acrylate, giving 92% yield of methyl cinnamate in the presence of N‐methylpyrrolidone (NMP) and triethylamine (Et₃N). The stability of the heterogeneous catalyst was also studied in detail. The catalytic tests showed that the palladium leaching correlated to solvent, base and palladium loading. The heterogeneous catalyst exhibited excellent stability towards loss of activity and palladium leaching was not observed during six recycles in the presence of toluene and Na₂CO₃. Copyright © 2007 John Wiley & Sons, Ltd.     

An efficient heterogeneous cross‐coupling of aryl iodides with diphenylphosphine catalyzed by copper (I) immobilized in MCM‐41

The heterogeneous cross‐coupling reaction of aryl iodides with diphenylphosphine was achieved in toluene at 115 °C in the presence of 10 mol% of phenanthroline‐functionalized MCM‐41‐supported copper (I) complex (Phen‐MCM‐41‐CuI) with Cs₂CO₃ as base, yielding various unsymmetric triarylphosphines in good to excellent yields. This protocol can tolerate a wide range of functional groups and does not need the use of expensive additives or harsh reaction conditions. This heterogeneous Cu (I) catalyst exhibited the same catalytic activity as homogeneous CuI/Phen system, and could easily be recovered by a simple filtration of the reaction solution and recycled up to seven times without significant loss of activity.     

Highly efficient and reusable polystyrene‐supported copper(II) catalytic system for S‐arylation of potassium thiocyanate by aryl halides in water

An inexpensive, efficient and environmentally friendly copper(II) catalyst supported on polystyrene was successfully synthesized and used as a heterogeneous catalyst for S‐arylation of potassium thiocyanate by aryl halides. Also this catalyst could be recovered and reused several times without any noticeable decrease in its catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.     

The first heterogeneous Sonogashira coupling reaction of aryl halides with terminal alkynes catalyzed by diatomite‐supported palladium(II) salophen complex

We report here our observation that, using appropriate reaction conditions, the Sonogashira reaction can be performed without the need for copper catalyst and solvent. Our approach involves the use of diatomite‐supported palladium(II) salophen complex as a catalyst and triethylamine as a base. The methodology works, to differing extents, for aryl iodides and bromides. This heterogeneous catalyst can be reused at least five times without any decrease in activity. Copyright © 2011 John Wiley & Sons, Ltd.     

MCM‐41‐Supported Bidentate Phosphine Rhodium Complex: An Efficient and Recyclable Heterogeneous Catalyst for the Hydrosilylation of Olefins

MCM‐41‐supported bidentate phosphine rhodium complex (MCM‐41‐2P‐RhCl₃) was conveniently synthesized from commercially available and cheapγ‐aminopropyltriethoxysilane via immobilization on MCM‐41, followed by reacting with diphenylphosphinomethanol and rhodium chloride. It was found that the title complex is a highly efficient catalyst for the hydrosilylation of olefins with triethoxysilane and can be recovered and recycled by a simple filtration of the reaction solution and used for at least 10 consecutive trials without any decreases in activity.     

Efficient construction of C–C bonds from aryl halides/aryl esters with arylboronic acids catalysed by palladium(II) thiourea complexes

A new set of palladium(II) complexes comprising phenyl(thiazolyl)thiourea ligands have been successfully synthesized and characterized with the aid of analytical as well as spectral (IR, UV–visible and NMR) methods. A distorted square‐planar geometry with N^S coordination mode of thiourea ligands in the new palladium complexes was corroborated by single‐crystal X‐ray diffraction methods. Interestingly, the palladium(II) thiourea complexes showed the highest catalytic activity with 0.1 mol% catalyst loading in Suzuki–Miyaura cross‐coupling reactions utilizing a range of aryl bromides/unactivated aryl chlorides with arylboronic acids as coupling partners in aqueous–organic media. Syntheses of diaryl ketones using aryl esters and arylboronic acids as coupling partners were also achieved with low catalyst loading within 20 h. The potential of our catalyst was demonstrated by its wide substrate scope, low catalyst loadings and high isolated yield. Moreover, the influences of key parameters like solvent, base, temperature and catalyst loading were also investigated.     

Ferromagnetic nanoparticle‐supported copper complex: A highly efficient and reusable catalyst for three‐component syntheses of 1,4‐disubstituted 1,2,3‐triazoles and C–S coupling of aryl halides

A new nanocatalyst was synthesized by immobilization of 4′‐(4‐hydroxyphenyl)‐2,2′:6′,2″‐terpyridine/CuI complex on ferromagnetic nanoparticles through a surface modification (FMNPs@SiO₂‐TPy‐Cu). This heterogeneous catalyst was characterized using various techniques including Fourier transform infrared and energy‐dispersive X‐ray spectroscopies, transmission and scanning electron microscopies, X‐ray diffraction, vibrating sample magnetometry and thermogravimetric analysis. The resulting nanocatalyst presented excellent catalytic activity for the regioselective syntheses of 1,4‐disubstituted 1,2,3‐triazoles and thioethers. The thermally and chemically stable, benign and economical catalyst was easily recovered using an external magnet and reused in at least five successive runs without an appreciable loss of activity.     

Anchoring of Cu(II)–vanillin Schiff base complex on MCM‐41: A highly efficient and recyclable catalyst for synthesis of sulfides and 5‐substituted 1H–tetrazoles and oxidation of sulfides to sulfoxides

A copper(II)–vanillin complex was immobilized onto MCM‐41 nanostructure and was used as an inexpensive, non‐toxic and heterogeneous catalyst in the synthesis of symmetric aryl sulfides by the cross‐coupling of aromatic halides with S₈ as an effective sulfur source, in the oxidation of sulfides to sulfoxides using 30% H₂O₂ as a green oxidant and in the synthesis of 5‐substituted 1H –tetrazoles from a smooth (3 + 2) cycloaddition of organic nitriles with sodium azide (NaN₃). The products were obtained in good to excellent yields. This catalyst could be reused several times without loss of activity. Characterization of the catalyst was performed using Fourier transform infrared, energy‐dispersive X‐ray and atomic absorption spectroscopies, X‐ray diffraction, thermogravimetric analysis, and scanning and transmission electron microscopies.