Hydrogen peroxide secondary alcohols, oxidation

Synthesis of secootkiry eokois from l-aOtynes. Dihydroboration at room temperature of a terminal alkyne with either (I) or 9-BBN gives a 1,1-diborylalkane (3) this is treated at 0-5° with I eq. of methyllithium in ether. The product (4) rearranges to (S). An alkyl halide (100 excess) is then added, and the resultant secondary organo-borane (6) is oxidized with alkaline hydrogen peroxide. Secondary alcohols (7) are obtained in 70-85% yield. 

Ci8H37)2(CH3)2N]io[SiW9 034] has been used in water at 65°C as an effective and recyclable catalyst for alcohol oxidation with hydrogen peroxide. Secondary alcohols have been oxidized to ketones in 6h with quantitative yields. For the oxidation of 2-octanol, the catalyst has been isolated by extraction with diethyl ether and recycled up to four times with no appreciable loss of activity and selectivity towards ketone formation. 

One of the exciting results to come out of heterogeneous catalysis research since the early 1980s is the discovery and development of catalysts that employ hydrogen peroxide to selectively oxidize organic compounds at low temperatures in the liquid phase. These catalysts are based on titanium, and the important discovery was a way to isolate titanium in framework locations of the inner cavities of zeolites (molecular sieves). Thus, mild oxidations may be run in water or water-soluble solvents. Practicing organic chemists now have a way to catalytically oxidize benzene to phenols alkanes to alcohols and ketones primary alcohols to aldehydes, acids, esters, and acetals secondary alcohols to ketones primary amines to oximes secondary amines to hydroxyl-amines and tertiary amines to amine oxides. 

Griffith has recently reported the synthesis and use of lanthanide heteropolyacid complexes with aqueous hydrogen peroxide for the oxidation of secondary alcohols.202 The complexes were [LnWi0O36]9 and [Ln(PWj 1039)2] 1 (Ln = La, Pr, Sm, Tb). However, the active oxidant was... 

Ruthenium(III) chloride has been shown to be particularly effective with hydrogen peroxide for the oxidation of alcohols under phase-transfer conditions.204 Primary alcohols are converted to acids, allylic and secondary alcohols to ketones, and benzyl alcohols to either benzaldehydes or benzoic acids. 

Heterocyclic compounds that have water bound covalently across a C=N bond behave as secondary alcohols. When subjected to very gentle oxidative conditions, they are converted into the corresponding 0x0 compounds. Potassium permanganate in 0. IN sodium hydroxide at room temperature has been used to oxidize 2- and 6-hydroxypteri-dine to 2,4- and 6,7-dihydroxypteridine, respectively. In contrast, 4-hydroxypteridine was not attacked by this reagent even at 100°. Hydrogen peroxide in acid solution was used to oxidize quinazoline quinazoline 3-oxide 1,3,5-, 1,3,7-, and 1,3,8-triazanaphthalene and pteridine (which hydrate across the 3,4-double bond in the... 

Experiments were made with pure 2-propanol samples stored for six months in white glass containers, which were half full and exposed to the light. It could be proved that peroxides form in these conditions. The experiment showed that peroxidation is faster when a ketone is present. The fact that this oxidation only takes place with secondary alcohols shows that it affects the hydrogen atom in the a position of the active group, (atom that is more reactive than a primary hydrogen), and not the actual function. 

A mixture of 1,4-dioxane and water is often used as the solvent for the conversion of aldehydes and ketones by H2Se03 to a-dicarbonyl compounds in one step (Eq. 8.117).331 Dehydrogenation of carbonyl compounds with selenium dioxide generates the a, (i-unsaturated carbonyl compounds in aqueous acetic acid.332 Using water as the reaction medium, ketones can be transformed into a-iodo ketones upon treatment with sodium iodide, hydrogen peroxide, and an acid.333 Interestingly, a-iodo ketones can be also obtained from secondary alcohol through a metal-free tandem oxidation-iodination approach. 

Oxidation of alcohol produces hydrogen peroxide and carbonyl compound simultaneously (aldehyde and ketone from primary and secondary alcohols, respectively). Carbonyl compound is formed as a result of alkylhydroxyperoxyl radical decomposition... 

The oxidation of primary and secondary alcohols in the presence of 1-naphthylamine, 2-naphthylamine, or phenyl-1-naphthylamine is characterized by the high values of the inhibition coefficient / > 10 [1-7], Alkylperoxyl, a-ketoperoxyl radicals, and (3-hydroxyperoxyl radicals, like the peroxyl radicals derived from tertiary alcohols, appeared to be incapable of reducing the aminyl radicals formed from aromatic amines. For example, when the oxidation of tert-butanol is inhibited by 1-naphthylamine, the coefficient /is equal to 2, which coincides with the value found in the inhibited oxidation of alkanes [3], However, the addition of hydrogen peroxide to the tert-butanol getting oxidized helps to perform the cyclic chain termination mechanism (1-naphthylamine as the inhibitor, T = 393 K, cumyl peroxide as initiator, p02 = 98 kPa [8]). This is due to the participation of the formed hydroperoxyl radical in the chain termination ... 

Tungsten-catalysed oxidation of alcohols by hydrogen peroxide is achieved in high yield in the presence of tetra-n-butylammonium hydrogen sulphate [20-22]. Secondary alcohols are converted into ketones (>90%) [e.g. 21], but primary alcohols generally are oxidized completely to the carboxylic acids [21], Aldehydes are also oxidized to the carboxylic acids [e.g. 21]. In contrast, using procedure 10.7.8.B, which is adaptable to scale up, benzyl alcohols are converted into the aldehydes benzoic acids are only formed with an excess of hydrogen peroxide [22],... 

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