Catalytic oxidation of aldehydes to carboxylic acids with hydrogen peroxide as oxidant

Selenium Catalyzed Oxidation of Aldehydes: Green Synthesis of Carboxylic Acids and Esters

“…Furthermore, this preliminary investigation also demonstrated that the aqueous medium is superior respect to the organic one (entry 8 vs. entry 5). When THF was used as the solvent in the presence of benzenseleninic acid ( 5 ) as catalyst, according to the conditions previously reported by Choi et al [29] lower yields were obtained, despite the use of a higher amount of catalyst. When diphenyl diselenide was substituted by HCl (4%) a 30% yield of 2a was obtained, evidencing only a slightly catalytic effect of the acidity in effecting the oxidation.…”

“…In order to evaluate the ability of diphenyl diselenide ( 3 ) to catalyze this reaction, we subjected the aldehyde 1a to the reaction with 2% of 3 at 50 °C in the presence of a stoichiometric amount of both hydrogen peroxide (30%) and methanol. After only two hours the reaction was complete evidencing a positive effect of the catalyst on allowing the conversion to proceed under considerably milder conditions and in shorter reaction times (90% yield in 2 h at 50 °C vs. 75% yield in 5 h at 75 °C [29]; Table 4, entry 1).…”

Efficient Method for Aromatic‐Aldehyde Oxidation by Cleavage of Their Hydrazones Catalysed by Trimethylsilanolate

“…NMR spectra were recorded in [D 6 ]DMSO with a Jeol ECX-500 (500 MHz) spectrometer. The following methods were used for compound analysis.…”

“…The oxidation of aldehydes with hydrogen peroxide has been extensively studied as a method in which the presence of a metal catalyst (e.g., complicated complexes of tungsten [4] or molybdenum [5] ) or a strong non-selective oxidizer (i.e., benzeneseleninic acid [6] ) is necessary. Recently reported additives (e.g., V 2 O 5 [7] or [VO(acac) 2 ] [8] ) suffer from poor selectivity (e.g., the oxidation of thioethers to the corresponding sulfoxides [9][10][11] ).…”

Oxidative Conversion of Aldoximes into Carboxylic Acid Esters Catalysed by Polystyrene-Bound Phenylseleninic Acid

“…1 The phenylseleninic acid/hydrogen peroxide oxidation system is widely known. It has been used in the epoxidation of olefins and in the Baeyer-Villiger reaction of ketones, [2][3][4] in the oxidation of allylic alcohols, 5 in the oxidation of sulfides, 6 in the oxidation of aldehydes 7 and phenolic system. 8 The oxidative conversion of aldoximes into carboxylic acid esters 9 catalysed by 2-nitrobenzeneseleninic acid also has been reported.…”