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Acylation of aromatic compounds by acid anhydrides using Preyssler's anion [NaP5W30O110]14- and heteropolyacids as green catalysts

Gharib A., Jahangir M., Scheeren J.(H.)W.

Polish Journal of Chemical Technology

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2011

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Vol. 13, nr 2

11-17

EN

The Preyssler, Wells-Dowson and Keggin heteropolyacids are efficient and eco-friendly solid acid catalysts for the acylation of electron-rich aromatic compounds with acid anhydrides. The performance of different forms of heteropolyacids was compared. In all the cases, the best results were obtained using the Preyssler heteropolyacid as the catalyst. In the presence of 25 mol% (with respect to H+ equivalency) Preyssler catalyst, highly para-selective acetylation of anisole occurs using two equivalents of acetic anhydride, in 15 min at room temperature. The isolated yield of the p-methoxyacetophenone product is 98%.

2

Epoxidation of 1,5,9-cyclododecatriene with H2O2 in the presence of tungstophosphoric acid (H3PW12O40)

Wołosiak A., Lewandowski G.

Polish Journal of Chemical Technology

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2010

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Vol. 12, nr 3

40-44

EN

The influence of the technological parameters on the epoxidation of 1,5,9-cyclododecatriene (CDT) to 1,2- epoxy-5,9-cyclododecadiene (ECDD) by the phase-transfer catalysis method (PTC) in the presence of tungstophosphoric heteropolyacid (H3PW12O40) and hydrogen peroxide as the oxidizing agent has been presented. The phase-transfer catalyst was AliquatŽ 336 (methyltrioctylammonium chloride). The epoxidation of CDT to ECDD in the PTC system proceed under the relatively mild condition: low temperature, lack of solvent, short reaction time. The effect of: the mixing velocity, the molar ratio of CDT:H2O2 and H2O2:H3PW12O40, the nature of the solvent and its concentration, was studied. The most advantageous technological parameters were: the mixing rate 400 – 600 rpm, the molar ratio of CDT:H2O2= 3:1 – 1.5:1, the molar ratio of H2O2:H3PW12O40= 200:1 – 400:1, the temperature 40 – 50°C, solvent: dichloromethane or lack of the solvent, dichloromethane concentration: 10 – 50 vol%, reaction time 35 – 50 min. The application of the above-mentioned parameters allows to achieve the yield of 44 – 47% ECDD in relation to introduced CDT.

3

Heteropolikwasy jako współczesne katalizatory reakcji estryfikacji

Witczak T., Grzesik M., Witczak M., Skrzypek J.

Przemysł Chemiczny

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2007

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T. 86, nr 1

42-47

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A new heterogeneous catalyst for the oxidation of organic compounds by hydrogen peroxide

Łukasiewicz M., Pielichowski J.

Polish Journal of Chemical Technology

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2004

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Vol. 6, nr 1

31-33

EN

A series of new heterogeneous catalysts for the oxidation of aromatic and alkyl aromatic compound using hydrogen peroxide as a catalyst were prepared. The described catalytic system is based on the introduction of heteropolyacids containing tungsten atoms into the polymeric chain. Polyaniline (PANI) was chosen as a matrix for its interesting properties (conductivity, insolubility in most common organic solvents). The catalyst was synthesized in both one-step or two step methods resulting in getting materials with different catalytic properties. The whole catalyst was characterized by UV-VIS and FTIR method. The thermal properties in both neutral and oxidative conditions were also investigated during the research. The resulting heterogeneous catalyst was tested in the oxidation of anthracene by the hydrogen peroxide. The reaction was proceeding in both the microwave and conventional conditions.

5

New heterogeneous catalyst for oxidation of organic compounds by hydrogen peroxide

Łukasiewicz M., Pielichowski J.

Polish Journal of Chemical Technology

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2003

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Vol. 5, nr 3

12-14

EN

A series of new heterogeneous catalysts for oxidation of aromatic and alkyl aromatic compound using hydrogen peroxide as a catalyst were prepared. Described catalytic system is based on introduction of heteropolyacids containing tungsten atoms into the polymeric chain. Polyaniline (PANI) was chosen as a matrix in order to its interesting properties (conductivity, insolubility in most common organic solvents). The catalyst was synthesized in both one-step or two step methods resulting in materials with different catalytic properties. All catalyst was characterized by UV-VIS and FTIR method. The thermal properties in both neutral and oxidative conditions were also investigated during the research. The resulting heterogeneous catalyst was tested in oxidation of anthracene by hydrogen peroxide. The reaction was proceeding in both microwave and conventional conditions.