Oxidative cleavage with ruthenium tetroxide

The oxidative cleavage of alkenes resulting in the formation of carboxylic acids is also accomplished with chromium trioxide in sulfuric acid or acetic acid [567, 569] with potassium dichromate in sulfuric acid [1111] and with ruthenium tetroxide, generated in situ from ruthenium trichloride... 

Amino acids. Oxidation of aliphatic primary amines with ruthenium tetroxide leads to complex products. However, oxidation of aralkylamines at pH 3.0 with periodate (12 eq.) and RuCls 3H2O (0.02 eq.) converts the aromatic ring into a carboxyl group to give amino acids. Cleavage is facilitated by a 4-methoxy or hydroxy substituent in the ring. ... 

Oxidation of internal acetylenes with ruthenium tetroxide gives the corresponding diketones with some of the acids resulting from cleavage. DMAD reacts with ethylene trithiocarbonate (134) to give ethylene and the l,3-dithiole-2-thione (135). Further study has indicated that acetylenes... 

Osmium tetroxide used in combination with sodium periodate can also effect alkene cleavage.191 Successful oxidative cleavage of double bonds using ruthenium tetroxide and sodium periodate has also been reported.192 In these procedures the osmium or ruthenium can be used in substoichiometric amounts because the periodate reoxidizes the metal to the tetroxide state. Entries 1 to 4 in Scheme 12.18 are examples of these procedures. Entries 5 and 6 show reactions carried out in the course of multistep syntheses. The reaction in Entry 5 followed a 5-exo radical cyclization and served to excise an extraneous carbon. The reaction in Entry 6 followed introduction of the allyl group by enolate alkylation. The aldehyde group in the product was used to introduce an amino group by reductive alkylation (see Section 5.3.1.2). 

Osmium tetroxide used in combination with sodium periodate can also effect alkene cleavage.135 Successful oxidative cleavage of double bonds using ruthenium tetroxide and sodium periodate has also been reported.136 In these procedures, the osmium or ruthenium can be used in substoichiometric amounts because the periodate reoxidizes the metal to the tetroxide state. Entries 1 4 in Scheme 12.17 are examples of these procedures. 

Ruthenium tetroxide is a four-electron oxidant which directly transforms alkenic compounds into oxidative cleavage products, i.e. carbonyl compounds and carboxylic acids.288 The reaction can be visualized as proceeding according to a [4 + 2] cycloaddition of the cis-dioxo moiety with the alkene, resulting in the formation of a RuVI cyclic diester which decomposes to ruthenium(IV) dioxide and oxidative cleavage products (equation 114).288 This reaction can be made catalytic... 

The physical properties, preparation and reactions of ruthenium tetroxide have been reviewed by Lee and van den Engh, Rylander," Haines and Hetuy and Lange. A more vigorous oxidant than osmium tetroxide, its reaction with double bonds produces only cleavage products. " Under neutral conditions aldehydes are formed from unsaturated secondary carbons while carboxylic acids are obtained under alkaline or acidic conditions. For example, Shalon and Elliott" found that ruthenium tetroxide reacted with compound (11) to give the corresponding aldehyde under neutral conditions, but that a carboxylic acid was formed in acidic or alkaline solvents (equation 23). 

Overall, ozone compares favorably with other approaches for oxidative alkene cleavage involving Osmium Tetroxide, Potassium Permanganate, Ruthenium(VIII) Oxide, Sodium Periodate, or chromyl carboxylates which are costly, toxic, involve metal wastes, and may require detailed workup procedures. 

Osmium tetroxide used in combination with sodium periodate can also effect alkene cleavage cleanly.Successful oxidative cleavage of double bonds using ruthenium... 

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