Sharif Digital Repository

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,... 

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... 

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,... 

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... 

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... 

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... 

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... 

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... 

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... 

We have reported a new and efficient synthesis of tetrahydrothiopyrano [2,3-b]indole skeletons via unique tandem reaction of indoline-2-thiones to Baylis-Hillman adduct acetates. This protocol is a very mild and simple method for construction heterocycles in a one-step process. This is a convenient and diastereoselective synthesis of methyl 4-aryl-2,3,4,9-tetrahydrothiopyrano[2,3-b]indole-3-carboxylate systems in the presence of K2CO3 in acetonitrile. The major benefits of the current study are the one-pot procedure, high yields and diastereoselectivity, short reaction times and the similarity of the products to the biologically active moieties.
In addition 1, 4-diazabicyclo [2.2.2]... 

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... 

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... 

In first part Mesoporous silica (SBA-15) was synthesized by template synthesis method and the surface of SBA-15 was functionalized with 3-glycidoxypropyltrimethoxysilane and 5-Phenyl-1H-tetrazole. Palladium nanoparticles were immobilized on the aforementioned mesoporous support. Characterization of catalyst regarding to its structure, morphology and other parameters was investigated by physiochemical analysis such as XRD, SEM, TEM, and TGA. This heterogeneous catalyst has high capability in reduction of nitrobenzenes and selective oxidation of primary alcohols which respectively gain aminoarenes and benzaldehydes in high yields. Reduction and oxidation reactions are done in water as a green... 

In this thesis, heterogenous catalysts based on magnetic nanoparticles coated with organosilanes and poly(ionic liquids) were synthesized. These catalysts were synthesized by hydrolysis of tetraethyl organosilanes and other organosilicons such as 3-aminopropyl triethoxy silane and polymerization of some monomers in the presence of ionic cross-link agents. The synthesized matrixes were used to stabilize precious metals such as Pd and Au. The magnetic properties of the catalysts aid to easy separation from the reaction medium by an external magnetic field. High thermal stability low toxicity and high-level loading of metals are some beneficiaries of the magnetic catalysts. At the end,... 

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%)  

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... 

Nowadays, using one-pot multicomponent reactions in the synthesis of organic and natural compounds has attracted a lot of attention due to their ideal synthetic features. These types of reactions play an important role in synthetic chemistry by reducing reaction steps, costs, wastes, and by-products and increasing the reaction efficiency as an efficient method. The issue that led to this project was the development of a novel procedure for developing synthetic methods for the synthesis of thioxo-pyrrolidine 3-carbutamide compounds. In this study, the first Mumm rearrangement was performed by using dithiocarbamates by applying ultrasonic irradiation. The reaction was investigated in methanol... 

In the first section, due to the important role of nanocatalysts in different fields of chemistry, magnetic metal ferrite nanoparticles were synthesized. Ferrite nanoparticles were synthesized using co-precipitation method and were characterized. Then, these nanoparticles were applied as catalyst system for one-pot β-ketophosphonates and thiophosphate synthesis.This is a green and efficient route for S-P and C-P bond construction using copper ferrite nanoparticles as catalyst. The application of a highly active recyclable heterogeneous nanocopper ferrite catalyst for the oxyphosphorylation reaction of various alkenes was conducted under ligand-free conditions, in acetonitrile as solvent at... 

In the first section, a novel and efficient multicomponent reaction for the synthesis of polysubstituted pyrrolidine derivatives is described under catalyst-free conditions using unltrasonic irradiation. The reactions were performed via a one-pot four-component condensation of secondary amines, carbon disulfide, isocyanides, and gem-dicyano olefins at room temperature to afford polysubstituted pyrrolidines diastereoselectively in 56-96% yields. This is the first report of Mumm-type rearrangement with dithiocarbamates followed by intramolecular cyclization which lead to the preparation of the key structure of pyrrolidine.In the second section, an efficient and unprecedented green protocol...