In oxidation of alcohols

It is a stable and safe oxidant which can replace oxodiperoxodipyridine-chromium(VI) in oxidation of alcohols to aldehydes [1]. The quinolinium analogue has also found similar application [2],... 

Catalytic oxidant.1 In combination with N-methylmorpholine N-oxide (7,244) as the stoichiometric oxidant, this ruthenium compound can be used as a catalytic oxidant for oxidation of alcohols to aldehydes or ketones in high yield in CH2C12 at 25°. Addition of 4A molecular sieves is generally beneficial. Racemization is not a problem in oxidation of alcohols with an adjacent chiral center. Tetrabutylammonium perruthenate can also be used as a catalytic oxidant, but the preparation is less convenient. 

Another reagent that finds application in oxidations of alcohols to ketones is ruthenium tetroxide. For example, the oxidation of 1 to 2 was successfully achieved with this reagent after a number of other methods failed. 

The following experimental tips help to achieve best yields in oxidations of alcohols to aldehydes and ketones with PDC.127a... 

A material with nitrogen-coordinated Ru was obtained from a silica-linked 2-(phenylazo)pyridine ligand. Results for cyclobutanol oxidation with 02 and the sacrificial oxidant isobutyraldehyde indicate that one- and two-electron oxidations occur simultaneously. The stability of the catalyst is not always guaranteed, probably because acids may be formed in oxidations of alcohols (284). Leaching problems are also encountered with a polymer-bound Ru Schiff base complex, used in oxidation of benzyl alcohol (285). 

The domain of oxidations with silver oxide includes the conversion of aldehydes into acids [63, 206, 362, 365, 366, 367 and of hydroxy aromatic compounds into quinones [171, 368, 369]. Less frequently, silver oxide is used for the oxidation of aldehyde and ketone hydrazones to diazo compounds [370, 371], of hydrazo compounds to azo compounds [372], and of hydroxylamines to nitroso compounds [373] or nitroxyls [374] and for the dehydrogenation of CH-NH bonds to -C=N- [375]. Similar results with silver carbonate are obtained in oxidations of alcohols to ketones [376] or acids [377] and of hydroxylamines to nitroso compounds [378]. 

Sodium bromate, NaBrOs, a white crystalline compound, converts acyloins into a-diketones under forcing conditions [740]. More often, this reagent is used as a reoxidant of ammonium cerium nitrate [421], cerium sulfate [741], or ruthenium trichloride [741] in oxidations of alcohols to aldehydes [421] or carboxylic acids [741]. 

Ba[Mn04]2 possesses similar chemoselectivities as Mn02 in oxidations of alcohols, but it is more readily available and does not require special treatment for its activation... 

Onium salts can also be used to support reagents that would transform a substrate. After reaction the IL phase can be recovered and the reagent regenerated for being reused in another cycle. For example, carboxylic acids have been supported on onium halides. Simply synthesized by quatemarisation of methylimidazole followed by acid hydrolysis, this compound can react with epoxides to afford halo-hydrines in 76-95% yields [58], Additionally, an OS supported version of TEMPO has been used in oxidation of alcohol into ketone [59] (Fig. 21). 

USE In bromination of olefins in oxidation of alcohols to aldehydes and ketones and of aldehydes to acid bromides. 

Formation of methylthiomethyl ethers is often observed in oxidation of alcohols by dimethyl sulfoxide-acetic anhydride. Suggest a mechanism that would account for the formation of these by-products. 

G. Tojo and M. Fernandez, in Oxidation of Alcohols to Aldehydes and Ketones, Springer, Berlin, 2006, pp. 1-97. 

Polystyrene-based immobilized ruthenium catalysts can be used in oxidation of alcohols with NMO, TEMPO/O2, or O2 [94]. Catalytic oxidative cleavage of vicinal diols to aldehydes with dioxygen was reported with RuCl2(PPh3)3 on active carbon [95]. Ionic liquids such as tetramethyl ammonium hydroxide and Aliquat 336 can be used as the solvent for the RuCl2(PPh3)3-catalyzed aerobic oxidation of alcohols [96]. 

Moriceau, R, Taouk, B., Bordes, E., and Courtine, P. Correlations between the optical basicity of catalysts and their selectivity in oxidation of alcohols, ammox-idation and combustion of hydrocarbons. Catal. Today 2000, 61,197-201. 

Rapid oxidation of secondary alcohols may be carried out using hydrated copper permanganate in dichloromethane. Water is an essential component in the reaction. Mixtures of potassium permanganate and copper sulphate may also be used, as may a variety of hydrated metal salts, although in these cases experimental details and yields were not reported. Bispyridinesilver permanganate has been shown to be an efficient reagent, soluble in organic solvents, for the oxidation of benzylic primary amines and alcohols to benzaldehydes. The intermediacy of nitrite esters is implicated in oxidations of alcohols with ferric nitrate on KIO bentonite. ... 

In oxidations of alcohols or aldehydes into carboxylic acids, chromic acid is one of several reagents, including several that are catalytic. For example nickel(II) salts catalyze oxidations by bleach. Aldehydes are relatively easily oxidised to carboxylic acids, and... 

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