Amides Ruthenium tetroxide

RCH2NH2 —> RCONH2The transformation of primary amines to amides can be effected by oxidation of N-Boc alkylamines with ruthenium tetroxide, generated in situ from Ru02 (catalytic) and NaI04 (excess) in aqueous ethyl acetate. Deprotection is effected with TFA in CH2C12. 

Amides containing methylene groups linked to the nitrogen atoms are oxidized to imides by ruthenium tetroxide, which is usually generated in situ from ruthenium dioxide or ruthenium chloride and sodium periodate... 

With the powerful formylation reagent IV -diformylacetamide imides are obtained from amides or lactams in good yield (equation 56). Oxidation reactions also have found some application in the synthesis of imides. For example, catalytic amounts of ruthenium tetroxide and 10% aqueous NaI04 as cooxidant in an optimized reaction medium (ethyl acetate-water) oxidize acyclic amides to imides. The reaction rate is inversely related to the electron-withdrawing power of the acyl group, i.e. the electron density at the nitrogen atom (equation 57). 

Apart from an alkaline hydrolysis affecting mainly ester and amide bonds a boron tribromide treatment and a ruthenium tetroxide oxidation were applied to the extracted residues. The BBr3-treatment cleaves aromatic and aliphatic ether and ester bonds. The oxidation using RuCU attacks the aromatic carbon atoms and releases, therefore, mainly unalterated aliphatic moieties. 

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