Sharif Digital Repository

Allyl, crotyl, methallyl and cinamyl ethers of 4-hydroxy-, 7-hydroxy-, and 4-methyl-7-hydroxycoumarins have been efficiently synthesized and rearranged to substituted allylcoumarins under microwave irradiation. Irradiation of allylcoumarins in the presence of BF3/ether directly produced substituted dihydrofurocoumarins in good yields  

Various thioamides, especially thiobenzanilides and thioacetomorpholides, bearing a heterocycle ring were efficiently prepared by a modified Willgerodt-Kindler reaction of quinaldine and α- and γ-picoline with anilines and morpholine in the presence of sulfur, and a catalytic amount of DABCO under microwave irradiation  

Nitriles are efficiently transformed to thiomorpholides via the Willgerodt-Kindler reaction under microwave irradiation in solvent-free conditions  

γ-Alumina is used to catalyze the Cannizzaro reaction in the absence of any base under microwave irradiation in high yields. In the case of terephthalaldehyde the reaction is carried out with high selectivity  

Perchloric acid immobilized on silica gel (SiO2-HClO4) has been utilized as a mild and cheap reagent for onepot preparation of different varieties of flavylium salts via tandem reaction of different acetophenones with Salicylaldehydes under solvent-free conditions. Different reaction conditions such as conventional heating and microwave irradiation have been investigated. The corresponding flavylium salts have been prepared in high yields. The procedure is milder and more convenient than the known procedures  

A novel and smart biopolymer-based hydrogel was synthesized by graft copolymerization of acrylic acid onto the salep backbones. The new superabsorbent hydrogel was synthesized via simultaneous crosslinking and graft copolymerization of acrylic acid (AA) monomer onto salep backbones using radiochemical methods. In radiochemical methods, γ-rays as initiator, energy source and crosslinker are applied. In our experiments, the effects of reaction variables such as relative contents of salep and AA, as well as γ-rays total dose were examined. According to water absorbency of the entitled network, the best synthesis condition is reported. FTIR spectroscopy, SEM photograph and TGA analysis were used... 

CO2-laser irradiation was used to modify the surface properties of thin-film composite (TFC) polyamide reverse osmosis (RO) membranes. These membranes were first synthesized via interfacial polymerization of m-phenylenediamine (MPD) monomers and trimesoyl chloride (TMC) over porous polysulfone ultrafiltration support, followed by a CO2-irradiation. AFM, ATR-FTIR, SEM and contact angle measurements were used to characterize the surface properties of these membranes. The ATR-FTIR results indicated that CO2-laser irradiation did not induce any functional groups on the membrane surface. However, it was found that the laser irradiation enhanced the NaCl salt rejection and slightly reduced the... 

Hetero-Diels–Alder reactions of [60]fullerene with α,β-unsaturated thio-oxindoles (3a, 3b, 3c), prepared from thio-oxindole 1 and heteroaromatic aldehydes (2a, 2b, 2c), to generate tetrahydrothiopyrano[2,3-b]indole [60]fullerene cycloadducts (5a, 5b, 5c) under thermal or microwave irradiation were described. The yields were improved, and the reaction time was decreased by conducting the reaction under microwave irradiation. © 2016 Wiley Periodicals, Inc  

Introduction: The aim of this work is to evaluate the effect of low-level laser irradiation (LLLI), by lasers with different wavelengths, on glycated catalase enzyme in vitro experimentally. Methods: This is done by measuring the activity and structure properties of glycated catalase enzyme. The structure properties were evaluated with circular dichroism (CD) and fluoroscopy methods. Three continuous wave (CW) lasers in the visible spectrum (λ = 450, 530, 638 nm) and a 100-ns pulsed laser in the infrared spectrum (λ = 905 nm) were chosen for comparison. For the infrared laser, same effects have been investigated for different energy doses. The effect of photon energy (hλ) at different... 

Red mud (RM) which emerges as a by-product from the alumina producing process has been used as an efficient catalyst for one-pot direct synthesis of nitrile compounds from aldehydes and hydroxylamine hydrochloride under microwave irradiation. ©ARKAT USA, Inc  

A solvent-free, solid-supported, and microwave-assisted thio-Claisen rearrangement of S-propargylated thioamides having an activated α-methylene group has been developed. The methodology could be used successfully for the synthesis of tri-substituted thiophenes and sulfur containing triarylamines. The reaction takes place in short time and in good isolated yield. © 2005 Taylor & Francis  

CuSO4/SiO2 is found to be an efficient and selective medium for the acetalization of aldehydes in the presence of ketones in solvent-free conditions under microwave irradiation. © 2005 Bentham Science Publishers Ltd  

Phenolic compounds and carboxylic acids are methylated with dimethyl carbonate in the presence of a catalytic amount of BF3· OEt2, DBU, or KOH, in good to excellent yields under microwave irradiation and solvent-free conditions  

An AlCl3-ZnCl2 mixture supported on silica gel is found to be a new efficient medium for the Beckmann rearrangement in solvent-free conditions under microwave irradiation. The yields are good to excellent  

Tabas coal sample from Iran was desulfurized with combination of microwave irradiation and peroxyacetic acid washing in a batch reactor. The effect of irradiation time and power, peroxyacetic acid reaction time and temperature and particle size on reduction of sulfur was investigated. For microwaved/acid washed samples, depending on desulfurization conditions, the reduction in pyritic, organic and total sulfur ranged from 26 to 91, 2.6 to 38.4 and 17 to 65%, respectively. Microwave irradiation had positive effect on desulfurization with peroxyacetic acid. For <300 μm size fraction, after irradiation, the reduction enhanced from 49.9 to 86.6% in pyritic sulfur, 23.8 to 35% in organic sulfur... 

The one-pot, three-component condensation of benzil, benzonitrile derivatives and primary amines on the surface of silica gel under solvent-free conditions and microwave irradiation provided tetrasubstituted imidazoles in high yields. © 2003 Elsevier Science Ltd. All rights reserved  

A simple method for the preparation of industrially important alkyl aryl ethers is reported. Several phenolic compounds such as phenols, naphthols, and hydroxy coumarins were O-methylated with trimethyl phosphite or trimethyl phosphate under microwave irradiation and solvent-free condition in almost quantitative yields. Reaction of 2-naphthol with trimethyl phosphate gave mixture of 2-methoxynaphthalene and 1-methyl-2-methoxynaphthalene while the reaction with trimethyl phosphite gave mostly 2-methoxynaphthalene. This method is highly efficient for the methylating of phenolic compounds with very easy experimental procedure and environmental friendly conditions  

Microwave induced Cannizzaro reaction, which was performed in presence of neutral γ-alumina as a polymeric catalyst, was discussed. Cannizzaro reaction was carried out on alumina surface and other unknown products were also obtained. Solvent extraction method was utilized to isolate mild and selective benzyl alcohol and carboxylic acids  

Aryl schiff bases were efficiently reduced to the corresponding secondry amines by triethylammonium formate/formic acid system under microwave irradiation in solvent-free condition  

A high-temperature superconductor slab irradiated by a desired pattern of light is proposed to behave as a completely controllable 2-D photonic media that could be applied in a wide range of photonic devices. In this case, the permittivity spatial variation, which is fundamentally required in many photonic devices, can be achieved by means of the selective variation of cooper-pair density under patterned irradiation. The process of photo-effect in superconductors is the proposed mechanism for the deformation of the spatial distribution of cooper-pair density and for the creation of nonuniform permittivity. In this perspective, the effects of nonuniform photon irradiation on the density of...