Potassium ferrate aldehydes

Oxidation. Potassium ferrate (VI) is a reagent for selective oxidation of primary alcohols and amines to aldehydes and of secondary alcohols to ketones. Double bonds, aldehyde functions, tertiary hydroxyl groups, and tertiary amino groups are resistant to oxidation. The reaction is carried out at room temperature either in water or in aqueous solvents. In fact water is essential for oxidation. The reaction is carried out at an initial pH of 11.5 the final pH is 13.5. In a typical procedure K.2pe04 (0.(X)2 mole)... 

In the case of carbohydrates, hydroxymethyl groups are selectively oxidized by potassium ferrate to aldehyde groups secondary hydroxyl groups are not affected.- ... 

Potassium ferrate, K2Fe04, which is prepared from ferric nitrate and alkaline hypochlorites [916], is a selective oxidant for the conversion of primary alcohols into aldehydes (not acids), of secondary alcohols into ketones, and of primary amines into aldehydes [917, 918]. 

The rarely used potassium ferrate transforms benzylic and allylic alcohols to aldehydes at room temperature in good to high yields. Saturated alcohols give unsatisfactory results [917, 918],... 

Potassium ferrate in aqueous solution at room temperature transforms 1-phenylethanoI in 18 min into acetophenone in 90% yield. However, under similar conditions, cyclohexanol gives a very low yield of the ketone (20-30%). The reagent does not attack double bonds and does not oxidize aldehydes [917. ... 

Schemes have been devised to substitute less toxic metals for more toxic ones. Potassium ferrate on K10 mont-morillonite clay has been used to replace potassium chromate and potassium permanganate in the oxidation of alcohols to aldehydes and ketones in 54-100% yields.153 The potassium ferrate is made by the action of sodium hypochlorite on iron(III) nitrate or by treatment of iron(III) sulfate with potassium peroxymonosulfate.154 After the oxidation, any excess oxidizing agent, and its reduced form, are easy to recover by filtration or centrifugation. In another case, manganese-containing reagents have been substituted for more toxic ones containing chromium and selenium (4.21).155 Selenium dioxide was used formerly in the first step and pyridinium chlorochromate in the second.

Potassium ferrate(VI) added to benzylamine in water, and shaken 1 min. until the purple color of the ferrate(VI) has disappeared benzaldehyde. Y 70%. -Similarly during 7 min. Cinnamyl alcohol cinnamaldehyde. Y 75%. - Unsaturation in the molecule as well as aldehyde, tert. alcohol, and tert. amine... 

Potassium ferrate, K2pe04, is a mild reagent for the oxidation of primary alcohols and primary alkylamines to aldehydes, and of secondary alcohols to ketones. lodonium nitrate, INO3, is reported to oxidize alcohols to carbonyl compounds electron-withdrawing groups adjacent to the alcohol carbon cause a marked decrease in reactivity olefinic alcohols undergo preferential electrophilic addition to the double bond. ... 

Aldehydes 2,4-Dinitrophenyl- hydrazine Formation of colored hydrazones or osazones. It is possible to distinguish between saturated and unsaturated hydrazones using potassium hexacyano-ferrate(III) [5]. [3,4]... 

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