Sharif Digital Repository

The site-selectivity and regioselectivity of Diels-Alder reactions of allenyl aryl ethers with cyclopentadiene and acrolein were studied. While cyclopentadiene (as an electron-rich diene) only reacted with the external double bond of allenyl aryl ethers to provide the site-selective normal electron demand Diels-Alder cycloadducts, acrolein (as an electron-deficient diene) reacted with the C1-C2 π bond of allenyl aryl ethers to provide the site- and regioselective hetero-Diels-Alder cycloadducts as exclusive products  

N-Benzyl-DABCO tribromide, a stable, solid organic ammonium tribromide, has been used as a bromine source for the regioselective and high-yielding bromination of aromatic amines and phenols. Mono-bromination proceeds well in the presence of a stoichiometric amount of bromine source at room temperature  

Benzothiazoles were readily prepared in one step from thiobenzanilides using N-bromosuccinimide in CH2Cl2-CCl4 (1:1V/V) at room temperature, with good yields under mild reaction conditions  

A facile and efficient synthesis of 2-oxindole derivatives bearing tetrahydropyrazine scaffold has been developed. Using water as solvent without any additional acid or metal catalyst, easy work up and high yield of products are the main advantages of this protocol. © 2018 Wiley Periodicals, Inc  

This study describes an odorless protocol for the synthesis of unsymmetrical sulfides via cobalt ferrite (CoFe2O4) catalyzed cross-coupling reaction of nitroarenes with alkyl halides in the presence of thiourea as sulfur source under ligand-free conditions. The catalyst was recycled using external magnetic field and reused for ten consecutive runs in the reaction of nitrobenzene, thiourea and benzyl bromide without significant loss of activity. Apart from being magnetically separable, being inexpensive and air-stable are another important features of this catalytic system. All the products were formed in good yields and short reaction times. © 2017 Elsevier B.V  

An efficient and unprecedented green protocol has been developed for the synthesis of N,S-heterocycles from styrenes and alkyl dithiocarbamates with high to excellent yields. The reaction of primary or secondary amines, CS 2, and styrenes was carried out in water in the presence of a catalytic amount of an inorganic base. All products were made by using an N -bromosuccinimide-H 2O combination as a green and inexpensive reagent. © 2020 American Institute of Physics Inc.. All rights reserved  

An eco-friendly gold-based catalyst supported on proline decorated montmorillonite was synthesized. The catalyst was characterized by combination of Fourier-transform infrared spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett Teller (BET) surface area analysis, Ultraviolet–visible spectroscopy (UV-Vis), Energy-dispersive X-ray spectroscopy (EDX), thermo gravimetric analysis (TGA) and atomic absorption spectroscopy (AAS) techniques. The synthesized catalyst was found to be a highly efficient heterogeneous nanocatalyst for multi component A3 coupling reaction of aldehyde, amine and alkyne... 

ZnO nanopowder has been successfully synthesized by a microwave-assisted solution approach using Zn(CH3CO2)2·2H2O and NaOH. The results obtained from X-ray diffraction (XRD), scanning electron microscopy (SEM) and transition electron microscope (TEM) show that the mean particle size is 30 nm. SEM and TEM micrographs of ZnO nanopowder also reveal that nanoparticles have spherical shape. Catalytic activity of ZnO nanopowder for O-acylation of alcohol and phenol has been investigated. The results show that the reaction time by using ZnO nanopowder has been reduced by almost 24 times with higher yield than ZnO bulk. © 2007  

(Chemical Equation Presented) An efficient and simple route is presented to the synthesis of some iminothiazolidinone derivatives. α-Chloro amide derivatives undergo coupling reaction with isothiocyanate in the presence of a mild base, followed by nucleophilic substitution of chlorine by the sulfur atom of isothiocyanate  

Basic silica gel (NaOH/SiO2) was found to be a very efficient media for the dehydrosulfenylation of sulfoxides in solvent-free condition under microwave irradiation  

An efficient and facile one-pot, five-component reaction for the synthesis of 2,6-diamino-1-alkyl-2-oxospiro[indoline-3,4′-thiopyran]-3,5-dicarbonitrile derivatives has been reported by a reaction between primary amines, carbon disulfide, malononitrile, and isatin derivatives. The major advantages of this procedure are high yields of products in relatively short reaction time, scalability, mild conditions, multi-component synthetic procedure, low catalyst loading, no column separation and simple reaction work-up. As a consequence, this synthetic procedure provided an efficient access to spirooxindole-annulated thiopyran derivatives. © 2022  

C15H10ClN3O3S, orthorhombic, Pbca (no. 61), a = 11.981(2) Å, b = 14.890(4) Å, c = 17.239(4) Å, V = 3075.4 Å3, Z = 8, Rgt(F) = 0.053, wRref(F2) = 0.123, T = 120 K. © 2014, Oldenbourg Wissenschaftsverlag München. All rights reserved  

Aldehydes and aryl alkyl ketones were efficiently transformed to thioamides with the same number of carbon atoms via Willgerodt-Kindler reaction under microwave irradiation in solvent-free conditions. The thioamides obtained were hydrolyzed to corresponding carboxylic acids with microwave dielectric heating in one minute. Both reactions are very fast and the yields are excellent  

A novel magnetic heterogeneous copper catalyst was synthesized by immobilization of copper ions onto triazole functionalized Fe3O4. The catalyst was fully characterized by FT-IR, TGA, CHN, SEM, TEM, EDX and atomic adsorption spectroscopy. The resulting catalyst was used in the synthesis of 1,2,3-triazoles via a one-pot three component reaction of alkynes, alkyl halides, sodium azides under green conditions. The catalyst was reused ten times and no significant loss of activity was observed  

An efficient 12-step route for the synthesis of the diterpenoid quinone (±)-danshexinkun A in 23% overall yield from the corresponding highly substituted stilbene using a photocyclization strategy is described  

An efficient method for the preparation of 2,3,5-trisubstituted thiophenes in a one-pot synthesis from thiomorpholides via the thio-Claisen rearrangement was developed. © 2003 Elsevier Ltd. All rights reserved  

An efficient one-step method for the synthesis of fully substituted thiophenes, from thiomorpholides and α-halo ketones, was developed. A mechanism has also been proposed for the course of reaction. © 2004 Elsevier Ltd. All rights reserved