Oxygen, phthalimides

The chemical properties of phthalocyanines depend mosdy on the nature of the central atom. Phthalocyanines are stable to atmospheric oxygen up to approximately 100°C. Mild oxidation may lead to the formation of oxidation iatermediates that can be reduced to the original products (29). In aqueous solutions of strong oxidants, the phthalocyanine ring is completely destroyed and oxidized to phthalimide. Oxidation ia the presence of ceric sulfate can be used to determine the amount of copper phthalocyanine quantitatively (30). 

Not many syntheses of phthalocyanines start with phthalimides. This may be due to the oxygen they contain because at elevated temperatures metal-oxygen bonds may be formed with a variety of metals during the synthesis. 

Diastereoselective tandem conjugate addition of both oxygen- and nitrogen-centred nucleophiles (potassium phthalimide, TsNHK, MeONa, and MesSiOK) to the novel (IN)-lO-camphorsulfonic acid-derived nitroalkenes (139 R = Me, Pr, and... 

In the fully and partially unsaturated oxygenated series, the syntheses of 2,5-dimethoxycarbonyl-3,6-diphenyl-l,4-dioxin 231 and 2,6-dimethoxycarbonyl-3,5-diphenyl-l,4-dioxin 232 were recently reported from methyl phenylchloro-pyruvate with potassium phthalimide and sodium imidazolide <2000CHE911>. 

Bromine trifluoride has found application in the conversion of (methylsulfanyl)thiocar-bonyl groups, bonded to carbon atoms in aromatic rings, oxygen atoms in alcohols and phenols, or to the phthalimide nitrogen atom, into trifluoromethyl groups.125... 

The mechanism of the aerobic oxidation of alcohols depends on the particular catalyst used. Two general mechanisms can be considered (1) the direct oxygenation of alcohols by 02 through a free-radical chain process initiated by the catalyst, and (2) the direct oxidation of the alcohol by the catalyst, which is then regenerated by 02. Both mechanisms are well illustrated [6] by the aerobic oxidations catalyzed by the persistent tetramethylpiperidine-N-oxyl (TEMPO) radical 1 and the nonpersis-tent phthalimide-N-oxyl (PINO) radical 2. 

As an approach to a better understanding of adhesion mechanisms between polyimide and copper, we have studied the interaction between a set of model molecules for a polyimide and vapor deposited polycrystalline copper. Thin films and adsorbates of benzene, phthalimide, methyl-phthalimide, benzene-phthalimide, and malonamid, which are representative of separate parts of the polyimide repeat unit, were deposited in situ on clean copper and examined by means of X-ray and Ultraviolet photoelectron spectroscopy (XPS and UPS). In contrast to the previously observed bonding to the carbonyl oxygen in polyimide, as Cu is deposited on polyimide, our results show that most of these polyimide model molecules bond to Cu, through electron transfer, with the imide nitrogen atom as the primary reaction site. 

Phthalimide.—Phthalic anhydride also yields other derivatives, viz., phthalimide and phthalyl chloride. When phthalic anhydride is treated with ammonia a compound is formed by replacement of the anhydride oxygen with the imide group, ( = NH),... 

In the case of the pinene-derived acyl nitroxide 31 [50], as well as the phthalimide-iV-oxyl radical 32 [56], the mechanism of the oxidation involves hydrogen abstraction by the reactive acyl nitroxide [58] (or phthalimidyl nitroxide), followed by trapping of the resulting carbon radical with either a second equivalent of nitroxide or by molecular oxygen (Scheme 19). Table 2 summarizes the results of oxidative desymmetrization using optically active nitroxides. 

---