Ruthenium oxidative decarboxylation

Ruthenium(III) catalyses the oxidative decarboxylation of butanoic and 2-methylpropanoic acid in aqueous sulfuric acid. ° Studies of alkaline earth (Ba, Sr) metal alkoxides in amide ethanolysis and of alkali metal alkoxide clusters as highly effective transesterification catalysts were covered earlier. Kinetic studies of the ethanolysis of 5-nitroquinol-8-yl benzoate (228) in the presence of lithium, sodium, or potassium ethoxide revealed that the highest catalytic activity is observed with Na+.iio... 

Ruthenium(in) catalyses the oxidative decarboxylation of n-butyric acid and isobutyric acid by ceric sulfate in aqueous acid. A mechanism for the Ru(III)-catalysed oxidation of o-hydroxybenzoic acid by an acidic solution of bromamine-B (PhS02-NNaBr, BAB) has been proposed based on a kinetic smdy. An ionic mechanism is suggested for the ruthenium(III) analogue of the Udenfriend-type system Ru(III)-EDTA-ascorbate-02, for the selective oxygen-atom transfer to saturated and unsaturated hydrocarbons. The kinetics of the oxidation of p-XC6H4CHPhOH(X =... 

Hydrogenation of 3-pyridinecarboxylic acids is apt to be accompanied by extensive decarboxylation (2S), but this unwanted reaction can be prevented by carrying out the reaction in the presence of one equivalent of base (33,79). Ruthenium (33), rhodium (29), platinum oxide (2S,59), and palladium (30) have all proved effective catalysts for reduction of pyridinecarboxylic acids to the saturated acid. 

Nicotinic acid forms some piperidine as well as nipecotic acid when it is reduced with hydrogen over ruthenium, rhodium or platinum oxide presumably decarboxylation involves the intermediate 3,6-dihydro compound (265), which behaves like a j8-keto acid (Scheme 189). 

Methyl />-tolyl sulfone has been prepared by oxidation of methyl 7>-tolyl sulfide with hydrogen peroxide 4 r or ruthenium tetroxide,6 by alkylation of sodium -toluenesullinate with methyl iodide 7,8 or with methyl potassium sulfate,9 by decarboxylation of -tolylsulfonylacetic acid,7 by thermal decomposition of tetramethylammonium -toluenesulfinate,10 by reaction of cw-bis-(%tolylsulfonvl)-ethene with sodium hydroxide (low yield),11 by the reaction of methanesulfonyl chloride with toluene in the presence of aluminum chloride (mixture of isomers),12 by... 

He considers A a disguised form of a /9-aldehyde acid and as such readily loses carbon dioxide. When nicotinic acid was reduced in dilute hydrochloride acid only 10% of piperidine was obtained, indicating a small amount of decarboxylation. Decarboxylation has been observed during the hydrogenation of nicotinic acid in aqueous solution in the presence of ruthenium (8), rhodium (16), and platinum oxide (49). It has been... 

The oxidation of aspirin by A-sodio-A-bromobenzenesulfonamide (bromamine-B, BAB) in aqueous HCIO4 is first order in BAB, fractional order in aspirin and inverse fractional order in H+. The reaction proceeds via decarboxylation, bromination, and AcOH loss, affording the product 2,4,6-Br3CeH20H. The oxidation of D-cycloserine (CS) by BAB in HCl is first order in BAB and fractional order each in CS and H+. The proposed mechanism assumes simultaneous catalysis by H+ and Cl ions and is consistent with the observed kinetic results. The oxidation of diethylamine by BAB catalysed by ruthenium(III) is first order in oxidant, catalyst and substrate, but inverse fractional order in H+. A mechanism in which the metal coordinates the nitrogen atom of the amine before a slow electrophilic attack on the nitrogen by BAB, elimination of HBr, attack by water, and disproportionation affords acetaldehyde and ethylamine, which undergoes a similar oxidation. " ... 

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