An efficient synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles by one-step condensation of  an aldehyde, benzil, ammonium acetate and primary amine in the presence of nanocrystalline magnesium aluminate under microwave irradiation is described. The advantages of this catalyst are including simple work-up, low cost and reusability. Compared with conventional methods, the ...

Unsaturated spirocyclic substrates bearing two alkenyl chains underwent ruthenium-mediated ring-rearrangement metathesis through relaying cyclohexene and cycloheptene moieties to give angularly fused tricyclics. In some instances where two products were expected, high degrees of selectivity were observed. In one instance the structural parameter leading to selectivity was very subtle; in others...

Site selectivity, regioselectivity and stereoselectivity of [2 + 3] cycloaddition of 4-trifluoromethylbenzonitrile oxide to polyunsaturated medium size rings including 1,5,9-cyclododecatriene, 11-membered sesquiterpenes, 1,3-cyclooctadiene and 5-vinyl-2norbornene were examined. Site selectivity was correlated with electron charges of alkenyl carbon atoms. Structure of the products has been esta...

The pillared-layer metal-organic framework of Ni2(BTEC)(bipy)3.3DMF.2H2O  (BTEC = 1,2,4,5-benzenetetracarboxylate; bipy = 4,4́-bipydine; DMF =N,Ń-dimethylformamide) was prepared, characterized and used as a precursor for preparation of NiO nanoparticles. The morphology and structure of NiO nanoparticles were characterized by XRD, SEM, FT-IR and EDX techniques.  I...

Cr2O3 nanoparticles were prepared using Cr(NO3)3.9H2O as starting material, triethanolamine (TEA) as template and water as green solvent under microwave irradiation. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), photoluminescence (PL) and Raman spectroscopy. The size distribution of individual particles we...

Achieving high selectivity in the Heck reaction of electronically unbiased alkenes has been a longstanding challenge. Using a nickel-catalyzed cationic Heck reaction, we were able to achieve excellent selectivity for branched products (≥19:1 in all cases) over a wide range of aryl electrophiles and aliphatic olefins. A bidentate ligand with a suitable bite angle and steric profile was key to ob...

cr2o3 nanoparticles were prepared using cr(no3)3.9h2o as starting material, triethanolamine (tea) as template and water as green solvent under microwave irradiation. the products were characterized by x-ray diffraction (xrd), transmission electron microscopy (tem), fourier transform infrared (ft-ir), photoluminescence (pl) and raman spectroscopy. the size distribution of individual particles we...

first row transition metal complexes of phthalocyanine are employed as catalysts for the oxidation of cyclohexene and cyclooctene using iodosylbenzene and pentafluoroiodosyl benzene. the catalysis was performed in dichloromethane: methanol:water (80:18:2) solvent mixture.  the products of the catalysis for cyclohexene are epoxycyclohexane, 2-cyclohexene-1-ol and 2-cyclohexene-1-one whereas for ...