Iranian Journal of Catalysis
Volume:2 Issue: 3, Summer 2012

The application of the [Pd{C6H3(CH2CH2NH2)-4-OMe-5-κ2-C,N}(μ-Br)]2 complex of 2-methoxyphenethylamine in the Heck coupling reaction was considered under both conventional and microwave irradiation conditions, and their results were compared. This complex is an efficient, stable and non-sensitive to air and moisture catalyst for the vinylation of substituted aryl halides with different electronic properties. The cross-coupled products were produced in good to excellent yields using a catalytic amount of this complex in N-methyl-2-pyrrolidone (NMP) at 130 °C. In comparison to conventional heating conditions, the reactions under microwave irradiation gave higher yields in shorter reaction times.

Easily prepared nanoZnO was found to be as an efficient catalyst in the synthesis of 1,4-DHPs via four-component reaction of 1,3-dicarbonyls, aldehydes and ammonium carbonate in water at 60 °C. The prepared nanoZnO was characterized by XRD and FT-IR analysis, while the determined specific surface area of nano catalyst by BET method was 33 m2/g.

Brønsted acidic ionic liquid triethylamine-bonded sulfonic acid {[Et3N-SO3H]Cl} efficiently catalyzes the one-pot multi-component condensation of 2-naphthol with arylaldehydes and dimedone (5,5-dimethylcyclohexane-1,3-dione) under solvent-free conditions to afford 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-ones in high yields and relatively short reaction times.

1,3-Dibromo-5,5-dimethylhydantoin (DBH) and benzyltriphenylphosphoniumtribromide (BTPTB) were used as efficient catalysts for the promotion of the synthesis of 1,8-dioxo-octahydroxanthene derivatives (DOXOs) via a one-pot three component condensation of aldehydes and cyclic 1,3-dicarbonyl compounds in the absence of solvent.

Fe3O4 nanoparticles were prepared by chemical coprecipitation method and was found to be a mild and effective catalyst for the efficient, one-pot, three-component synthesis of 2,4,5-trisubstituted imidazoles at room temperature under ultrasound irradiation. The high yields of products and short reaction time were attributed to the nanosize of about 20 nm in which the catalyst could act as a nanoreactor. This methodology is found to be fairly general and catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction.

An one-pot method has been developed for the synthesis of azo dyes via sequential diazotization–diazo coupling of aromatic amines with coupling agents at room temperature in the presence of Bi(NO3)3. 5H2O. Short reaction times, high yields, a clean process, simple methodology, easy work-up and green ‎conditions are advantages of this protocol.‎

In this paper CuFe2O4, nanocrystalline powders were prepared. Also, the supported Cu ferrite was obtained by impregnation of the supports with Cu and Fe nitrates solutions, for calcination temperature 450 ºC. The samples were characterized by X-ray powder diffraction (XRD) and Fourier transform-infrared spectroscopy (FT-IR). Photocatalytic degradation of acid red 206 in water was studied. CuFe2O4 was supported on Clinoptilolite using solid-state dispersion (SSD) method. The results show that the CuFe2O4/zeoliteis an active photocatalyst. The maximum effect of photodegradation was observed at 10 wt. %CuFe2O4, 90 %wt. Clinoptilolite. A first order reaction with k = 0.123 min-1 was observed. The effects of some parameters such as pH, amount of photocatalyst, initial concentration of dye were examined.

An efficient one-pot oxidation/condensation tandem process has been developed for the synthesis of 2-substituted benzimidazole derivatives from benzylic alcohols and 1,2-phenylenediamine with use of urea-hydrogen peroxide/silica phosphoric acid as a bifunctional catalyst. This method provides a rapid and efficient access to 2-substituted benzimidazoles.