Facile sonochemical heterocyclization of 2,5-dimethoxy tetrahydrofuran with primary amines using sulfonated MWCNTs as a recyclable catalyst in aqueous media

<p>A set of <i>N</i>-substituted pyrrole derivatives have been designed and synthesized using sulfonated multi-walled carbon nanotubes as a recyclable heterogeneous catalyst under ultrasound irradiation. This reaction was carried out between 2,5-dimethoxy tetrahydrofuran and primary amines in water under green conditions. This method has some advantages such as: short reaction times, excellent product yields, simplicity of the procedure, easy work-up and high purity of products.</p

Microwave Assisted Synthesis of Two-Substituted Benzoxazoles in the Presence of Potassium Cyanide Under Mild Conditions

<div><p>Various two-substituted benzoxazoles were prepared using microwave-assisted reaction of 2-aminophenol with aromatic aldehydes in the presence of one equivalent of potassium cyanide as an equimolecular catalyst. Aldehydes having either electron-donating or withdrawing groups afforded the target products. The important features of this method were high yields, short reaction times and easy work up. The structure of synthesized products was characterized by nuclear magnetic resonance (NMR) and infrared (IR).</p></div

Microwave-assisted practical and simple method for heterocyclization of <i>o</i>-phenylenediamine and aldehydes using DDQ as oxidant agent

<p>In this research, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) has been used in the condensation reaction between <i>o</i>-phenylenediamine and various arylaldehydes as oxidants under microwave irradiation. In this clean reaction, the benzimidazole derivatives were synthesized as benefit target products. The advantages to this procedure include high yields, easy work-up procedure, no chromatographic separation, and short reaction times. The obtained pure products were characterized by physical and spectral data such as IR, ¹H NMR and ¹³C NMR techniques.</p

Immobilized triazine bis[mercapto amine] complexes of Pd(0) anchored nickel ferrite as a nanocatalyst for C–C coupling reaction

<p>Immobilized triazine bis[mercapto amine] complexes of Pd(0) (NiFe₂O₄@TABMA-Pd(0)) was easily synthesized and applied as highly efficient and versatile nanocatalyst for the synthesis of various <i>trans</i> stilbenes with high performance for the Heck coupling reaction of several types of aryl halides under thermal conditions. In short reaction time, excellent yields of <i>trans</i> stilbene derivatives have been achieved using NiFe₂O₄@TABMA-Pd(0) catalyst.</p

Synthesis of 2-arylbenzothiazoles using nano BF₃/SiO₂ as a reusable and efficient heterogeneous catalyst under mild conditions

<div><p>2-Arylbenzothiazoles were synthesized via condensation of 2-aminothiophenol and different aldehydes catalyzed by nano silica-supported boron trifluoride (nano BF₃/SiO₂) as an efficient and reusable catalyst in high yields and short reaction times. The reactions proceeded at room temperature under mild conditions to afford 2-arylbenzothiazole derivatives. The pure products were identified and characterized by physical and spectroscopic data such as IR, ¹H NMR, ¹³C NMR and Mass spectroscopy.</p></div

Facile preparation and characterization of some novel Schiff base complexes of uranyl(II), nickel(II), and zinc(II) ions

<p>Some Schiff base complexes of UO₂(II), Ni(II) and Zn(II) ions derived from the reaction of 2,5- dihydroxybenzaldehyde with aliphatic and aromatic diamins have been synthesized. The resulting ligands and their complexes have been characterized by infrared, ¹H NMR, ¹³C NMR and mass spectra. In these efficient reactions, Schiff base complexes with important applications in analytical and organic chemistry have been yielded.</p> <p>In this research, synthesis and characterization of some new Schiff base ligands derived from the reaction of 2,5-dihydroxybenzaldehyde with various aliphatic and aromatic diamines and their complexes using UO₂(II), Ni(II), and Zn(II) metal ions are reported. The ligands are found to be bound to the metal atom through the oxygen atoms of the hydroxyl groups and nitrogen atoms of imine groups. Fourier transform infrared, UV–Vis, magnetic susceptibilities, ¹H NMR, ¹³C NMR, and mass spectra were used to investigate the structures of prepared materials. In these efficient protocols, Schiff base complexes were obtained in high yields and appropriate reaction times.</p

Microwave-promoted total synthesis of <i>N</i>-(α-hydroxybenzyl)formamides using DMSO/H₂O under neutral conditions

<p>A total synthesis route toward <i>N</i>-(α-hydroxybenzyl)formamides by microwave-assisted reaction of dichloroaziridines and aqueous dimethyl sulfoxide is described. The corresponding products were obtained in excellent yields with reduced reaction times. The obtained formamides were characterized by various techniques such as Infra red (IR), Nuclear Magnetic Resonance (NMR) and mass spectroscopy data.</p

Facile one-pot synthesis of 2-arylbenzothiazoles catalyzed by H₃PO₄/TiO₂-ZrO₂ (1/1) under solvent-free conditions

<p>A highly efficient and simple protocol for the preparation of 2-arylbenzothiazoles through condensation of 2-aminothiophenol and different aldehydes in the presence of H₃PO₄/TiO₂-ZrO₂(1/1)-cetyl pyridinium bromide (CPB) is described. The reaction proceeded under mild and solvent-free conditions to afford 2-arylbenzothiazole derivatives. In this method, the title compounds were obtained in good to excellent yields and short reaction times. The structures of synthesized products were identified by infrared, ¹H NMR, ¹³C NMR, and mass spectroscopy.</p

Sonocatalyzed facile synthesis of 2-aryl benzoxazoles using MnO₂ nanoparticles as oxidant agent under mild conditions

<p>Nano MnO₂ was found to be an efficient oxidant agent for the synthesis of 2-substituted benzoxazoles through one-pot reaction of <i>o</i>-aminophenol and different aromatic aldehydes in acetonitrile under ultrasonic irradiation. This method was performed under mild conditions with high yields, inexpensive and readily available oxidant agent, facile and easy experimental procedure, simple purification of final products, and short reaction times. The prepared nano MnO₂ has been characterized by FTIR, XRD, and SEM techniques. The pure products were identified and characterized by physical and spectroscopic data such as; melting point, IR, ¹H NMR, and ¹³C NMR.</p