Sharif Digital Repository

ZnFe2O4 nanoparticles have been successfully prepared through a controlled microwave–assisted co-precipitation as well as conventional co-precipitation. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were used for the structural, morphological and magnetic investigation of the product. Average particle size was obtained as 12 nm from XRD. Catalytic activity of ZnFe2O4 nanopowder for O-acylation of alcohol and phenol has been investigated. A trace amount of ZnFe2O4 has been effectively used as a nanocatalyst for the acylation of alcohol and phenol in acetic anhydride.

 

We have reported a new and efficient synthesis of a broad spectrum of heterotetracyclic benzoxazocines via unique tandem 1,3-dinucleophilic addition of different bifunctional nucleophiles to quinolinium and isoquinolinium salts. The reaction generally involves the initial addition of nucleophiles to quinolinium salts to form enamine intermediate which can be trapped by intramolecular O/S-alkylation of nucleophiles. This protocol is a very mild and simple method for construction of eight-membered ring in fused heterocycles in a one-step process. We have also developed an efficient asymmetric synthesis of α,β-disubstituted γ-bisalkoxycarbonyl and α, β- disubstituted γ- phosphono sulfonates via... 

In the first chapter, three efficient synthesis of novel polyheterocyclic indole and thiochromone-annulated thiopyranocoumarin derivatives are achieved via domino Knoevenagel hetero Diels–Alder reaction of O-acrylated and O-propargylated salicylaldehyde derivatives with indolin-2-thiones and 4-hydroxy dithiocoumarin. The domino Knoevenagel-hetero-Diels–Alder reactions are very efficient process that allows the formation of two or more rings at once, avoiding sequential chemical transformations. The products are formed in good-to-excellent yields with high regio- and stereoselectivity. The major advantage of this reaction is the ease of the work-up during which the products can be isolated... 

Oxidation reactions in organic chemistry were applied as one of the most important methods to change the functional groups to desired one. Oxidation of alcohols to aldehydes or oxidative coupling of thiols to disulfids is two well-known examples of these conversions. The mention reactions are using commonly because of availability and simple synthesis of the alcohols and thiols. Recently the application of immobilized reagents in solid surfaces is increased because of environmental advantages.
In this study, The 1,4-diazabicyclo[2.2.2] octane (DABCO) tribromide was immobilized on two different supports by employing 3-chloropropyltrimethoxy silane: Silica Support (SS), and Nanoparticles... 

We have reported a new and efficient synthesis of a broad spectrum of heterotetracyclic benzoxazocines via unique tandem 1,3-dinucleophilic addition of different bifunctional nucleophiles to quinolinium and isoquinolinium salts. The reaction generally involves the initial addition of nucleophiles to quinolinium salts to form enamine intermediate which can be trapped by intramolecular O/S-alkylation of nucleophiles. In the third part, as continues, we have reported another method which consists of Anthocyanidins and Thioindoles by using water and acetic acid as the solvent. This protocol is a very mild and simple method for construction of eight-membered ring in fused heterocycles in a... 

In this project, Fries rearrangement of aryl benzyl ethers and ary benzyl carbonates, using catalyst and microwave irradiation in solvent-less system have been studied, and Benzylated phenols which have attracted a great deal of interest, due to their medicinal properties, were synthesized. The solvent-free Fries reactions have many advantages such as: reduced pollution, low costs, and simplicity in process and handling. We report the use of N-benzyl DABCO tribromide as an electrophilic bromine source and one of the OATBs for one-step oxidative coupling procedure of benzyl cyanides into Symmetrical α,ά -dicyanostilbenes. The reaction proceeds easily with higher yields and shorter reaction... 

Stachys species have played crucial role as a folk-medicinal plants since so many years ago. According to their commercial interest in the production of essential oils and flavoring agents, investigation through their secondary metabolisms still has been done. In the first part of this research, we have done our phytochemical investigation of Stachys inflata. The aerial parts of this plant have been collected; we could isolate and identify 5 molecules. Their structural elucidation was accomplished by extensive spectroscopic methods including 1H NMR, 13C NMR and 13C Dept experiments. In the second part of the research, we have reported a new and efficient synthesis of a broad spectrum of... 

ZnO nanopowder has been successfully synthesized by a microwave-assisted solution approach using Zn(CH3CO2)2.2H2O and NaOH. The results obtained from XRD, SEM and TEM show that the mean particle size is 30 nm. SEM and TEM micrographs of ZnO nanopowder also reveal that nanoparticles have spherical shape. A convenient one-pot multi-component reaction of aromatic aldehydes, enolizable ketones or β-keto esters and acetonitrile in the presence of acetyl chloride and 10 mol % ZnO nanoparticles for the synthesis of β-acetamido ketones/esters at room temperature is described. Catalytic activity of ZnO nanopowder for o-acylation of alcohol and phenol has also been investigated. On the other hand,... 

Fused pyrimidines have attracted considerable attention recently in synthetic organic chemistry because of their wide range of biological activities pharmaceutical, therapeutic properties, antibacterial, antiviral, antitumor, and anti-inflammatory activities. We have reported a new and efficient synthesis of dihydro and tetrahydro pyrimidines fused to 2H-chromen-2-oneand cyclohex-2-enone and pyrimidine fused to uracil via two component reaction of 4-amino-2H-chromen-2-one, 3-aminocyclohex-2-enone and6-aminouracilto 1-aryl-N,N'-bis(arylmethylene)methanediaminein the present of iodine as catalyst.Molecular iodine has received considerable attention in the last few years due to inexpensive,... 

The ability of Ferro spinels to catalyze the reactions, along with their ability to become easily separated, has attracted many attentions. These Ferro spinels are synthesized in an efficient way and are used as a catalyst for carbon-carbon bond formation. Nanoparticles of Spinel ferrites, for instance three-metal ferrites, have unique characteristics and have very interesting and important applications in synthetic organic chemistry. In the first section of this thesis, synthesis and analysis of copper cobalt ferrite is considered. In the second section, several organic chemical reactions are investigated to evaluate the catalytic activity of these nanoparticles. Finally, the catalytic role... 

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 the first section, due to the important role of nanocatalysts in different fields of chemistry, magnetic metal ferrite nanoparticles were synthesized. Cobalt Cupper ferrite magnetic nanoparticles were synthesized using co-precipitation method and were characterized. The carbon−heteroatom bond forming reaction is one of the most important reactions in organic synthesis, pharmaceutical, dye, agrochemical, and biomolecules.1 Therefore, improvement of efficient methodologies for generating carbon−heteroatom bonds received considerable attention. An efficient protocol was developed for the nano CoCuFe2O4 catalyzed C-N and C-S bond formation. By this catalytic system, both amine and... 

1,3-Dipolar cycloaddition reactions constitute one of the most fundamental reactions for construction of five-membered heterocyclic compounds Spiro and dispirooxindoles have become important synthetic targets as these structural frameworks form the core units of many naturally occurring molecules that possess abundant biological activities .In this report we used (E)-Aryl ideneindolinones as unusual dipolarophiles for synthesis of dispirooxindoles. In follow different bifunctional nucleophiles for example 1,3-dicarbonyl, phenol, thioindole can be used in synthesis of benzoxazocines We have reported a new and efficient synthesis of benzoxazocines via unique tandem 1,3-dinucleophilic addition... 

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 the first section, due to the important role of nanocatalysts in different fields of chemistry, magnetic metal ferrite nanoparticles were synthesized. Nickel ferrite and cobalt ferrite magnetic nanoparticles were synthesized using co-precipitation method and were characterized. Then, these nanoparticles which have been crystalized in spinel structure were employed to catalyzed different C-C and C-heteroatom bond formation reactions through C-X bond activaion. In all cases, the proposed catalytic systems could catalyze the reactions efficiently and the optimized reaction conditions were milder and more effective than the previous reported methods. In the next section, C-halogen bond... 

Today, heterocycle compounds have become increasingly important in organic chemistry syntheses. Many extracellular compounds have a confirmed biological property. Due to the high bioactivity of these compounds, the development of their synthetic methods has received considerable attention and numerous reports have been published on their synthesis. One of the most commonly used examples is terazosin. It was first marketed as a blood pressure lowering drug but was later used in the treatment of benign prostate gland.Another important class of these compounds may be the different derivatives of the pyrimidine molecule used in the treatment of cancer. The use of hetero- cyclic compounds is not... 

A novel magnetic heterogeneous copper catalyst was synthesized by immobilization ofcopper ion onto the triazole functionalized Fe3O4. The catalyst was fully characterized by FTIR, TGA, CHN, SEM, TEM, EDX and atomic adsorption spectroscopy. The resulting catalystwas used in the synthesis of 1,2,3-triazoles via one-pot three component reaction of alkynes,alkyl halides, sodium azides under green condition. The catalyst was reused for ten times andno significant loss of activity was observed. Supported gold (III) on poly(ionic liquid) coated on magnetic nanoparticles produced a highly active, stablerecoverable and high loading for the synthesis of propargylamines (A3 coupling reaction) under... 

In this project, imine reactions produced from arylglyoxals were investigated in reaction with Kojic acid and 4-Hydroxycoumarin in presence of metalic lewis acids. Synthesis of furochromen and furocumarin derivatives, as two important class of bioactive compounds, were done in this research. All structures were identified by analytical and spectrometric devices

 

2-flavylium skeletons (2- Phenylbenzopyrylium salts), are often found as the basic structure in anthocyanins; the chromophores in natural pigments which are responsible for intense colors of fruits, leaves and flowers. They are present in plant organs, also to prevent them from environment predation and to protect the plant against ultraviolet irradiation especially in leaves. Aside from their contribution in plant parts, in industry, anthocyanines serve as food colorant, laser dyes and hair growing agents and have considerable biological and pharmaceutical activities like antioxidant, anti cancer, anti inflammatory, anti atherosclerosis, cardio protection and anti aging properties. almost... 

Herein, we report an efficient one-pot four-component reaction of commercially available 1,3-dicarbonyl compounds, aromatic aldehydes, amines, and nitromethane in the presence of ZnO nanoparticles, which leads to highly substituted pyrroles in moderate to good yields. A mild and efficient tandem process for the synthesis of highly substituted α-pyrones starting from 2-arylacetic acid of high com-mercial availability has been developed. The synthesis is based on the Knoevenagel condensation of 1,3-cyclohexadiones to various β-keto-Esters, followed by lactonization in the presence of 20 mol% ZnO as a nanocatalyst. Moderate to high yields, easily available and less expensive starting materials...