Oxidants in acetonitrile

In 1979, Diaz et al. produced the first flexible, stable polypyrrole (PPy) film with high conductivity (1(X) Scm ). The substance was polymerized on a Pt-electrode by anodic oxidation in acetonitrile. The then known chemical methods of synthesis " usually produced low conductivity powders from the monomers. By contrast, electropolymerization in organic solvents formed smooth and manageable films of good conductivity. Thus, this technique soon gained general currency, stimulating further electropolymerization experiments with other monomers. In 1982, Tourillon... 

In solvents that strongly resist anodic oxidation as MeCN, CH2CI2/CF3CO2H, or T SOjH CH-bonds in the alkyl chain can be oxidized. In acetonitrile a preferential acetamidation in the (co-2)- and ((B-l)-position occurs (Eq. 43) [352]. 

The conversion of oximes to nitroalkanes has been achieved by employing an Mo(IV) oxodiperoxo complex as oxidant in acetonitrile. Both aldoximes and ketoximes are converted into the corresponding nitroalkanes (Eqs. 2.61 and 2.62),123 representing a complementary synthetic route to the use of the UHP method. 

Electrochemical arylation of trialkyl phosphites by anodic oxidation in acetonitrile, a process that is troubled by low yield and formation of a variety of by-products.9... 

For the sake of comparison and mutual validation of methods for measuring large follow-up reaction rate constants, it is interesting to apply different methods to the same system. Such a comparison between high-scan-rate ultramicroelectrode cyclic voltammetry, redox catalysis, and laser flash photolysis has been carried out for the system depicted in Scheme 2.25, where methylacridan is oxidized in acetonitrile, generating a cation radical that is deprotonated by a base present in the reaction medium.20... 

RNHCT oxidation in aqueous solution at pH 13 at an Hg anode (Iversen and Lund, 1969). RNHO oxidation in dimethyl sulfoxide-Et4NBF4 at a PT anode (Bordwell and Liu, 1996) the published potentials were converted from the ferricinium/ferrocene reference to SCE by adding 0.51V (Bordwell et al., 1991). c RNHOH oxidation in acetonitrile-NaC104 at a glassy carbon anode (Sayo et al, 1973 Ozaki and Masui, 1978). 

The greater impact of substituents on ease of oxidation in acetonitrile than in water (Table 10) is due to the importance of solvation of the radical cation in more... 

Alkanes are functionalised by anodic oxidation in acetonitrile, methanol, acetic acid and more acidic solvents such as trifluoracetic acid and fluorosulphuric acid. Reaction requires very positive electrode potentials (see Table 2.1) and platinum has generally been used as anode materials in laboratory scale experiments. On a larger scale carbon is used as anode material. The first stage in these reactions in-... 

A third important reaction of aromatic radical-cations is carbon-carbon bond formation with a further aromatic substrate. This reaction is limited to the oxidation in acetonitrile of substrates with electrondonating substituents. Radical-cations from benzene, naphthalene and anthracene form a-complexes but do not form a a-bonded reaction intermediate. Tlie dimerization reaction has been investigated both by pulse-radiolysis [22] in water and by electrochemical methods [27] in acetoni-... 

N,N-Dialkylamides undergo a related series of reaction steps on anodic oxidation. The immonium ion from dimethylformamide can be generated in solution by oxidation in acetonitrile with no added nucleophile [100]. Solutions of the ion are used in further reactions such as with 1,1-diphenylethene forming 22. When acetic... 

In manchen Fallen lassen sich Reaktionen der hier beschriebenen Art nicht unter den stark sauren Bedingungen der Hofmann-Loffler-Reaktion durchfuhren. Man kann dann die (z. B. intramolekulare) N-Alkylierung mittels Silber(I)-oxid in Acetonitril/Wasser (9 1) bewerkstelligen6. Beispiele fiir diese Arbeitsweise sind die intramolekularen Dehydrochlo-rierungen von 1-Chlor-azocan zu Hexahydropyrrolizin (72%) und von 1-Chlor-azonan zu Octahydroindolizin (57%)6 ... 

The solvent may influence the course of such coupling reactions. Thus N-trifluoracetyl-l-benzyltetrahydroisoquinolines (82) cyclize on anodic oxidation in acetonitrile to neospirodienones (83), whereas morphinandienones (84) are formed in methanol-acetonitrile [Eq. (70)].147... 

When the sodium salt of 1-methylcorypalline (165 R = CH3) was oxidized in acetonitrile, a good yield of carbon-carbon dimer (69%) was obtained, in which only one of the enantiomeric pairs was obtained.251 The results were explained by proposing a surface mechanism in which the isoquinoline rings are adsorbed in a planar fashion. If the reacting molecules are adsorbed on the surface with methyl groups projecting upward, only those... 

This compound may result when other nucleophilic materials are treated with nitric oxide in acetonitrile solvent, common reaction conditions for diazeniumdiolate preparation. Poly(diazeniumdiolates)can be violently unstable and need handling with care. 

In this method, the bromide ion is converted to 2-bromoethanol by reaction with ethylene oxide in acetonitrile diisopropyl ether under acidic conditions. The 2-bromoethanol thus produced is determined by gas chromatography using an electron capture detector. 

Spectrophotometric data for the stability constants of complexes of Me3SnCl with substituted pyridine JV-oxides in acetonitrile show (76) that these constants correlate linearly with the [Pg.81]

Tri-r-b utylaniline is oxidized in acetonitrile to a radical cation. This reacts with pyridine to form 60% 6,8-di-r-butylpyrido[ 1.2 a] benzimidazole (38) by r-buiy 1-transfer to acetonitrile and subsequent dehydrogenation and 25% of the amidine 39. 

Dialkyl, diaryl, alkyl aryl, and heterocyclic tellurium oxides are known. Most of these compounds are white solids that are soluble in sodium hydroxide. Diorgano tellurium oxides appear to be oxidized by atmospheric oxygen. Their exposure to air should be minimized5. The protonation constant of dimethyl tellurium oxide in water was found to be 6 (pKa)6,7, and of bis[4-methoxyphenyl] tellurium oxide in acetonitrile 14.9s. The barrier to inversion for dihydrogen tellurium oxide (H2Te = 0), the parent compound of diorgano tellurium oxides, was determined as 92.4 kJ/mol (22.0 kcal/mol) by extended Hiickel calculations9. 

Several polymethyl-1,2-diphenylcyclobutenes, 82a-c, subjected to DCA-photo-oxidation in acetonitrile, afford 1,4-diketones 83a-c together with moderate amounts of the ozonides 85a-c, apparently formed from oxiranes, 84a-c, produced in the primary step ... 

Enzyme assays were performed in 1.5 mL microcentrifuge tubes containing 165 /nL of incubation buffer (0.25 M Tris-HCl, 0.1 mM EDTA, pH 7.4), 50 fiL of 10 mM glutathione in incubation buffer, and 25 /nL of appropriately diluted enzyme. The reaction was initiated by addition of 10 /nL of benzo [a]pyrene-4,5-oxide in acetonitrile (0.875 mg/mL). The assay was stopped by addition of 0.25 mL of acetonitrile containing 300 /nM 2-methoxynaphthalene as an internal standard. The solution was kept overnight in the dark at 4°C, and then 500 /nL of distilled water was added. The mixture was centrifuged before analysis by HPLC. Production of both the glutathione and diol derivatives was linear with time and protein up to 15 minutes and 500 /ng/mL, respectively. 

In the anodic oxidation, adamantane is a unique compound among alkanes. It has a rather low oxidation potential, and its anodic oxidation in acetonitrile affords acetamidoadamantane (1 equation 6) in 90% yield.<... 

Formation of S" " is revealed by an orange coloration of the solutions when phenothiazine is electrochemically oxidized in acetonitrile and by a golden color when sulfuric acid is used as an oxidant. Characteristic absorption maxima located at 271, 437 and 515 my. were assigned to this species.The same spectrum is recorded when equivalent quantities of phenothiazine and phenothiazine-5-oxide are dissolved in 66% perchloric acid, " the sulfoxide being first converted by the acid into T+ (see Scheme 2, Section IV,B,2), then reduced to S" " by phenothiazine (R) as shown by Eq. (3) (Section IV,B,1). 

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