Sharif Digital Repository

Three Keggin-type heteropolyacids were impregnated upon halloysite to produce heterogeneous acidic catalysts for synthesizing 5-hydroxymethylfurfural (5-HMF). Comparing the effectiveness of variously prepared catalysts in producing 5-HMF from fructose revealed the important role of halloysite in the final catalyst's acidic properties and performance in the reaction of halloysite-supported silicotungstic acid. Adjusting the reaction parameters for obtaining optimal results for the catalyst of choice was conducted via Response Surface Methodology and it was found that use of catalyst with 11 wt.% active ingredient at 125 °C in DMSO solvent yielded the target compound with 99.5% after 43 min.... 

The magnetic MOF-based catalytic system has been reported here to be an efficient catalyst for running CDC reactions and synthesis of Triazole rings under optimal conditions. The robust MOF catalyst was built based on magnetic nanoparticles and HKUST-1 which further modified with thioacetamide and carbonization. The catalyst structure was confirmed by various techniques. Furthermore, the products’ yields were obtained in good to excellent for all reactions under mild conditions which result from superior activity of the synthesized heterogeneous catalyst containing Cupper. Also, the magnetic property of the MOF-based catalyst makes it easy to separate from reaction mediums and reuse in the... 

Polysaccharide is important in terms of their environmental interest, scientists have been growing. According to the structural properties of this interesting class of natural polymers, in terms of having chemically active groups on the high density polymer housing provides the possibility That can perform chemical reactions with the new properties of these polymers to give. Starch polysaccharides in the project through a chemical reaction to the structure of a third type of bridge Amen to that using 1HNMR and 13CNMR predicted structure was approved. The modified polysaccharide has catalyst activity. This activity in knovenagel reaction for some aldhydes was used and results were... 

The magnetic MOF-based catalytic system has been reported here to be an efficient catalyst for synthesis of carbamates under optimal conditions. The robust MOF catalyst was built based on magnetic nanoparticles and HKUST-1 which further modified with thioacetamide and carbonization. The catalyst structure was confirmed by various techniques. Furthermore, the products’ yields were obtained in good to excellent for all reactions under mild conditions which result from superior activity of the synthesized heterogeneous catalyst containing Cupper. Also, the magnetic property of the MOF-based catalyst makes it easy to separate from reaction mediums and reuse in the next runs. In summary, the... 

In this thesis, heterogenous catalysts based on poly(ionic liquids) were synthesized. These catalysts were prepared by polymerization of functionalized ionic liquid monomers in the presence of an ionic cross-linker. Several types of poly(ionic liquids) such as acidic ionic liquid, basic ionic liquid and their complexs with copper and palladium were prepared. Some of these polymers were coated onto the magnetic nanoparticles to produce a catalyst with magnetic prppertise with easy magnetic separation from the reaction medium. Such catalysts have high loading level and high thermal stability. Most of prepared catalysts have high loading level due to the macromolecular nature of polymer. At the... 

Influence of attachment of Multi Walled Carbon Nanotubes (MWCNT) on various nickel nanocatalysts produced by the electroless plating method was investigated via Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), Atomic Absorption Spectroscopy (AAS), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) measurements, Temperature Programmed Reduction (TPR) and Temperature Programmed Oxidation (TPO) tests. Application of TPR/TPO data to Kissinger (Redhead) Equation yielded the activation energies of both nickel reduction and nickel oxidation reactions. Addition of MWCNT improved the catalytic effects by easing of... 

Two new copper(II) complexes, [CuL2] and [Cu(phox)2], were synthesized by reaction of 1-((4-bromophenylimino)methyl)naphthalen-2-ol, HL, and 2-(2′-hydroxyphenyl)-2-oxazoline, Hphox, as ligands and copper(II) acetate mono-hydrate with the ratio 2:1 (ligand:metal), respectively. For characterization and structure determination of synthesized complexes, different techniques were performed such as FT-IR, elemental analyses (CHN), and X-ray crystallography. The geometry around Cu atom is almost square planar in both complexes. The catalytic activity of the complexes was evaluated in azide–alkyne cycloaddition reaction in water without need of any additional agent. The reaction conditions for the... 

A new dioxomolybdenum(VI) complex, (Cis-[MoO2(L)])n, has been synthesized by reacting 4-bromo-2-((2-hydroxy-5-methylphenylimino)methyl)phenol as a ligand and [MoO2(acac)2] in methanolic solution. For characterization and structure determination of the synthesized complex, different techniques were performed such as elemental analyses, 1H NMR, IR, UV-Vis and X-ray crystallography. The complex was tested as a catalyst for the homogeneous epoxidation of olefins, using tert-butyl hydperoxide (TBHP) as an oxidant. The catalytic system showed high yield, selectivity and turnover number in olefin epoxidation reactions under atmospheric conditions. For example, when the molar ratio of catalyst,... 

Epoxidation of alkenes by Mn(III)meso-tetra(4-sulfonatophenyl)porphyrin chloride (MnTPPS4Cl) in the various homogeneous and heterogeneous catalytic systems was investigated. In the case of homogeneous catalysis, epoxidation of cyclooctene in CH2Cl2/MeOH mixture using urea hydrogen peroxide (UHP) as an oxidant and imidazole as a co-catalyst results in the formation of cycloocetene oxide in 87% yield. Using this catalytic system various alkenes successfully oxidized to their corresponding epoxide in high conversions and selectivity. Cyclic alkenes oxidized more easily than linear alkenes. In addition, epoxidation of alkenes was investigated in the heterogeneous catalytic systems. For this... 

In this study a new Ni(II)-¬oxazoline complex was synthesized by reaction of Ni(CH3COO)2.4H2O and 2-(2׳-hydroxyphenyl)-2-oxazoline ligand in MeOH solvent. The resulting complex bis[2-(2׳-hydroxyphenyl)-2-oxazolinato]Ni(II), was characterized by different spectroscopic methods. X-ray diffraction showed that this complex is four coordinated with a square planner geometry. The complex was applied as an efficient homogeneous catalyst in C-C coupling Heck reaction of arylhalides with olefins such as methylacrylate. Investigation of the catalytic activity of the complex in Heck reaction between arylhalides and olefins showed high yield and selectivity. For example reaction between iodobenzene and... 

Nowadays application of metallic catalysts in many of the organic reactions has been developed; therefore, different types of catalysts have been produced and used. In this way, in the first part of this thesis magnetic cobalt ferrite and nickel ferrite nanocatalysts were synthesized using co-precipitation method and their activity as catalyst was investigated in C-O bond formation reaction. This reaction was carried out between different types of aryl alcohols and aryl halides with good to excellent yields. The results showed that using N,N-dimethyl formamide as solvent, potassium carbonate as base and 5mol% of nanocatalysts at 80°C are the optimized condition for this reaction. In the... 

In nature, catalysis is of vital importance in a wide variety of biochemical processes catalyzed by metalloenzymes. The functions performed by the metalloenzymes and their significance have inspired a range of biomimetic studies, and intense efforts have been concentrated on the synthesis of low molecular weight complexes to model the spectroscopic features of such enzymes. Concomitantly, a challenging frontier in the field of biomimetic chemistry is the development of highly reactive model compounds that are able to effect rapid and selective substrate conversion. Some important catalytic transformations that have gained attention in recent years involve the carbon-carbon coupling, olefin... 

An efficient catalyst-free one-pot three-component reaction was developed for the synthesis of a new family of N- and S-containing spirocyclic compounds.Various derivatives of spirobenzimidazolidine containing an indole scaffold were synthesized for the first time in a modestly toxic solvent and under mild reaction conditions. The reaction times were of the order of several minutes, and all the products were obtained in moderate to high yields (overall yields 58–80%)  

In this study various ionic liquids (ILs) and their mixtures were coated on Pt/Al2O3 catalyst and the resulted IL-coated catalyst were used in synchronous hydrogenation of cyclohexene and acetone. The rate constants (k) and seletivities (S) toward C=O hydrogenation were determined for several catalysts in various solvents. The solvatochromic parameters (ETN, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen- bond acceptor basicity; α, hydrogen-bond donor acidity) were determined for used ILs and solvents and all obtained selectivities were modeled based on solvatochromic parameters of IL layer and bulk solvent using Multiparameter Linear Regression (MLR) method for... 

The magnetic MOF-based catalytic system has been reported here to be an efficient catalyst for synthesis of benzonitriles and diarylethers of aryl halides under optimal conditions. The MOF catalyst was built based on magnetic nanoparticles and UiO-66-NH2 which further modified with 2,4,6-trichloro-1,3,5-triazine and 5-phenyl tetrazole and the catalyst structure was confirmed by various techniques. Furthermore, the products’ yields were obtained in good to excellent for all reactions under mild conditions which result from superior activity of the synthesized heterogeneous catalyst containing palladium. Also, the magnetic property of the MOF-based catalyst makes it easy to separate from... 

In recent years, the use of various catalysts has become a powerful tool in the synthesis of a wide range of biologically important molecules and or natural products toward the formation of carbon-carbon and carbon-heteroatom bonds. In the first section, the synthesis of magnetic catalyst based on acrylonitrile was reported and an attempt was made to use an efficient support and ligand to immobilize copper metals. Then, its structure was characterized by different techniques. The catalytic activity of the prepared catalyst was confirmed in the formation of indolyl diketones and the desired products were successfully synthesized with good to excellent yields. In addition, the catalyst could... 

Nowadays, because of the importance of saving energy resources and also environmental issues, utilization of catalysts are increased in industry and products. In the last decades, a lot of efforts have been devoted to develop novel methods for heterogenizing of the homogeneous catalyst in order to combine the advantages of the both the homogeneous and the heterogeneous catalysts. Among the different solid supports, graphene with high surface area and distinctive mechanical and electronical properties have been introduces as an emerging support for heterogenizing of the homogeneous catalysts. On the other hand, the use of ionic liquid has been developed due to a broad range of polarity, low... 

Formation of C-C and C-hetero atom bonds in coupling reactions is among the most important organic chemistry reactions, which is useful for achieving the complex molecules from simple ones. The goal of this thesis, was using the organometallic and also metal free methods in coupling reactions and getting the advantage of them in the synthesis of novel hit compounds. In this way, some novel reactions were designed and some novel catalysts were synthesised and identified. Finally, computational quantum chemistry and computational drug design were used as powerful tools for supporting the reaction mechanism, electronic and structural studies and pharmacological evaluation. C-X bond activation... 

In the first part of this thesis, the application of core-shell magnetic nanoparticles supported V(V), Mo(VI) and Mn(III) complexes in the catalytic oxidation and reduction reactions was discussed. A magnetically recyclable vanadium(V) catalyst was synthesized by covalent anchoring of VO(salen)Cl on silica coated Fe3O4 nanoparticles. These nanoparticles were efficient catalysts for selective oxidation of sulfides to corresponding sulfoxides with urea hydrogen peroxide in excellent yields. Leaching and recycling experiments revealed that the nanocatalyst can be applied for nearly complete oxidation of sulfides for at least five successive cycles. A manganese(III) complex was immobilized on... 

Due to many vast application of C-C bond formation in the areas including bioactive compounds and natural products, over the past few years, the C-C coupling reactions have become a versatile tool in organic synthesis.First, a two-metal catalyst (CoFe2O4) was synthesized and its catalytic activity was evaluated in unsymmetrical thioether synthesis which offered an odorless, ligand-free and aryl halide-free rout for the formation of desired products. The catalyst was recovarable and was able to catalyze the reaction for 10 runs with retention of catalytic activity.In the next step, three-metal catalyst (CoCuFe2O4) was synthesized using the co-precipitation method and characterized.Then, these...