ChemInform Abstract: Heteropolyanions as Oxidation Catalysts in a 2‐Phase System.

Schwegler, M. A.; Floor, M.; Bekkum, H. van

doi:10.1002/chin.198826090

Cited by 33 publications

(44 citation statements)

References 1 publication

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“…These catalysts are very important for industries associated with fine chemicals, flavours, pharmaceuticals and foods [3,4] and are also used as industrial catalysts for several liquidphase reactions [5,6] such as alkylation [7,8], esterification [9,10] and reductive amination [11]. From among heteropoly acids and H-type zeolites, polytungstic acids and HZSM5 have been widely used in various organic reactions because they are strong Bronsted and Lewis acids [12,13].…”

Section: Intruductionsmentioning

confidence: 99%

Synthesis of 4,4′-diaminotriphenylmethane derivatives using H3PW12O40 and HZSM5 zeolite under solvent-free conditions

Alinezhad

Ardestani

Noroozi

2009

JICS

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An efficient and very simple method for synthesis of 4,4ǯ-diaminotriphenylmethane and its derivatives has been achieved via reaction of various substituted aromatic aldehydes containing both electron-donating and electron-withdrawing groups with various anilines having electron-withdrawing and electron-donating groups in the presence of catalytic amounts of HZSM5 zeolite and H 3 PW 12 O 40 under solvent-free conditions. The reaction proceed with shorter reaction time and higher yield compared to the results obtained in different solvents. Anilines having electron-donating groups in comparison with those having electrondonating group performed this transformation in better yields. Also the results show that the steric hindrance plays an important role in this transformation. Reusability is an advantage of the HZSM5 zeolite, while it showed lesser activity than H 3 PW 12 O 40 . The one-pot reaction, simple work up, high yields, use of efficient catalytic amount and eco-friendly reagents are the advantages of the proposed method. All products were characterized using 1 H NMR, 13 C NMR and IR.

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Section: Intruductionsmentioning

confidence: 99%

Synthesis of 4,4′-diaminotriphenylmethane derivatives using H3PW12O40 and HZSM5 zeolite under solvent-free conditions

Alinezhad

Ardestani

Noroozi

2009

JICS

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“…Silica-supported and -included heteropoly acids exhibit high activity in a range of acid-catalyzed reactions, including the alkylation of benzene by 1-octene [43], trans-de-tert-butylation, and the alkylation of phenols [45,46], in addition to a range of esterification [47] and hydrolysis [44] reactions. More recent studies on esterification reactions using heteropoly acids supported on MCM-41 [48] suggest that the formation of H 2 O during reaction can result in re-dispersion of HPA salt on the surface.…”

Section: Post-modified Mesoporous Solid Acidsmentioning

confidence: 99%

Solid acids and their use as environmentally friendly catalysts in organic synthesis

Wilson

Clark

2000

Pure and Applied Chemistry

280

126

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Tightening environmental legislation is driving the fine and speciality chemicals industries to consider alternative processes that avoid the use of conventional mineral acids. The use of heterogeneous catalysts in these processes would vastly simplify catalyst removal, minimizing the amount of waste formed. However, diffusion limitation of liquids within porous solids dictates that effective solid acids for liquid-phase reactions require the use of mesoporous materials <20-100Å. Recent developments in materials chemistry has led to the discovery of a family of ordered mesoporous silicas which opens up new possibilities for preparing solid-acid catalysts for liquid-phase reactions. This review concentrates on recent developments in the synthesis of new mesoporous solid acids for liquid-phase organic synthesis.

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“…These compounds possess unique properties such as: well-defined structure, Brönsted acidity, possibility to modify their acid-base and redox properties by changing their chemical composition (substituted HPAs), ability to accept and release electrons, high proton mobility, being environmentally benign and presenting fewer disposal problems [36]. Because of their stronger acidity, they generally exhibit higher catalytic activity than conventional catalysts such as mineral acids, ion exchange resins, mixed oxides, zeolites, etc [37]. They are used as industrial catalysts for several liquid phase reactions [38], such as alcohol dehydration [39], alkylation [40] and esterification [41].…”

Section: Introductionmentioning

confidence: 99%

Heteropolyacids as an efficient and reusable catalytic system for the regiospecific nitration of phenols with metal nitrates

Baghernejad¹,

Heravi²,

Oskooie³

et al. 2012

Bull. Chem. Soc. Eth.

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ABSTRACT. Highly regiospecific mononitration of phenols and substituted phenols is accomplished employing a metal nitrate and a catalytic amount of heteropolyacid in acetonitrile. An exclusive ortho-selectivity was observed with excellent yields. A variety of metal nitrates were used to obtain o-nitrophenols exclusively in good to excellent yields. The use of heteropolyacid is key for the selectivity observed.

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ChemInform Abstract: Heteropolyanions as Oxidation Catalysts in a 2‐Phase System.

Cited by 33 publications

References 1 publication

Synthesis of 4,4′-diaminotriphenylmethane derivatives using H3PW12O40 and HZSM5 zeolite under solvent-free conditions

Synthesis of 4,4′-diaminotriphenylmethane derivatives using H3PW12O40 and HZSM5 zeolite under solvent-free conditions

Solid acids and their use as environmentally friendly catalysts in organic synthesis

Heteropolyacids as an efficient and reusable catalytic system for the regiospecific nitration of phenols with metal nitrates

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