Phthalocyanine as catalyst

A variety of aUcenes can be converted to aziridines with PhINTs in good yields (48-90%) using iron phthalocyanine as catalyst (Scheme 24) [79]. It is noteworthy... 

A practical method of modification of polysaccharides by clean oxidation using H2O2 as oxidant and cheap iron phthalocyanine as catalyst has been developed. Since no acids, bases or buffers and no chlorinated compounds were used, a pure product can be recovered without additional treatment. Importantly, this flexible method provides materials with a wide range of DScho and DScooh just by an appropriate choice of the reaction conditions. Oxidized polysaccharides thus obtained possess various, tailormade hydrophihc/hydrophobic properties which have been tested successfully in cosmetic and other apphcations. 

Transition-metal -phthalocyanines as catalysts in acid medium. To prevent carbonate formation by the carbon dioxide in the air or that produced by oxidation of carbonaceous fuels, an acid electrolyte is necessary hence it is important to find electrocatalysts for an acid medium. Independently of Jasinski, we were soon able to show 3>4> that under certain conditions the reduction of oxygen in dilute sulfuric acid proceeded better with phthalocyanines on suitable substrates than with platinum metal. The purified phthalocyanines were dissolved in concentrated sulfuric acid and precipitated on to the carbon substrate by addition of water. This coated powder was made into porous electrodes bound with polyethylene and having a geometrical surface of 5 cm2 (cf. Section 2.2.2.1.). The results obtained with compact electrodes of this type are shown in Fig. 6. 

Benzyl phenyl sulphide was oxidized to benzyl phenyl sulphone quantitatively in 6h with iron phthalocyanine as catalyst. Experiments were similarly carried out with other metal phthalocyanines using phenyl and benzyl phenyl sulphides. Experiments using copper phthalocyanine, nickel phthalocyanine and no catalyst, were carried out for 24 h and the products analysed by HPLC. These results are presented in Table-1. In these experiments... 

Network Planar Polymers of Phthalocyanines as Catalysts or Adsorbents... 

The catalytic formation of cyclic carbonates via aluminium porphyrins was probably the trigger for the investigation run by Kasuga and coworkers in 1996 with aluminium phthalocyanines as catalysts.In general phthalocyanines display the same planar N4-coordination geometry as the porphyrins as shown in Scheme 18.35 with the advantage of an easier synthesis and have been used in many homogeneous catalytic reactions. 

Air oxidation of dyestuff waste streams has been accompHshed using cobalt phthalocyanine sulfonate catalysts (176). Aluminum has been colored with copper phthalocyanine sulfonate (177,178). Iron phthalocyanine can be used as a drier in wood oil and linseed oil paints (179). 

Similarly, the metal-free equivalent of phthalocyanine 21 was obtained in a yield of 30% by heating phthalonitrile 20 in the presence of magnesium sulfate, sodium sulfate, urea, and ammonium molybdatc(IV) as catalyst at 260-280 C for 2 hours.4 4... 

The formation of ROO and RO radicals, and M" =0 species is expected when phthalocyanines and porphyrins are used as catalysts (21, 22). The formation of the epoxide, Fignre 49.1, may be associated with the attack of metal oxo species (Fe = O) to the double bond (23). For a-pinene this attack is possibly favored by its rigid structure that causes an orbital overlapping, making the allylic hydrogen abstraction difficult (24). 

Copper, and occasionally silver, have been used as catalysts for hydroformylation of a-olefins. Phosphite complexes of copper(I) chloride have been claimed as catalysts (126). Phthalocyanine complexes of Group IB metals have been stated to show a low degree of catalytic activity (127). One of the more interesting examples of copper catalysis was disclosed by McClure (128). Copper powder, with a controlled amount of water (0.2-4.0 moles H20/mole Cu), gave a slow conversion of pro-... 

A mild aerobic palladium-catalyzed 1,4-diacetoxylation of conjugated dienes has been developed and is based on a multistep electron transfer46. The hydroquinone produced in each cycle of the palladium-catalyzed oxidation is reoxidized by air or molecular oxygen. The latter reoxidation requires a metal macrocycle as catalyst. In the aerobic process there are no side products formed except water, and the stoichiometry of the reaction is given in equation 19. Thus 1,3-cyclohexadiene is oxidized by molecular oxygen to diacetate 39 with the aid of the triple catalytic system Pd(II)—BQ—MLm where MLm is a metal macrocyclic complex such as cobalt tetraphenylporphyrin (Co(TPP)), cobalt salophen (Co(Salophen) or iron phthalocyanine (Fe(Pc)). The principle of this biomimetic aerobic oxidation is outlined in Scheme 8. 

Metal phthalocyanines with different metals as central atom, presently are still theoretically investigated, may become important in several new technologies, such as optical communication, as catalysts or in medical applications. Part of the new compounds will be represented by pigments [28]. 

Reaction 38 shows that hydroxylamines can cause amination at allylic positions. Fe(II) phthalocyanine (222c) was the most effective catalyst. Other catalysts and substrates were also investigated623. Complexes of Mo(VI) were less effective than 222c as catalysts for amination processes of this type624. 

Various metallo-phthalocyanines (Pht) and metallo-tetraphenylporphyrins (TTP) have been tested as catalysts for the oxidation of sulfides into sulfones by hydrogen peroxide. TPPFe(III)Cl in ethanol was the only catalyst tested to give 100% conversion into sulfones in under 5 min sulfoxides were identified as intermediates. PhtFe(III) gave sulfoxides in 100% yield and PhtMn(III) and TPPMn(III)Cl gave the sulfoxides in up to 70% yields. The absence of any by-product, in particular disulfide,... 

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