A Novel Oxidizing Reagent Based on Potassium Ferrate(VI)¹

Abstract

A new, efficient preparation has been devised for potassium ferrate(VI) (K(2)FeO(4)). The ability of this high-valent iron salt for oxidizing organic substrates in nonaqueous media was studied. Using benzyl alcohol as a model, the catalytic activity of a wide range of microporous adsorbents was ascertained. Among numerous solid supports of the aluminosilicate type, the K10 montmorillonite clay was found to be best at achieving quantitative formation of benzaldehyde, without any overoxidation to benzoic acid. The roles of the various parameters (reaction time and temperature, nature of the solvent, method of preparation of the solid reagent) were investigated. The evidence points to a polar reaction mechanism. The ensuing procedure was applied successfully, at room temperature, to oxidation of a series of alcohols to aldehydes and ketones, to oxidative coupling of thiols to disulfides, and to oxidation of nitrogen derivatives. At 75 degrees C, the reagent has the capability of oxidizing both activated and nonactivated hydrocarbons. Toluene is turned into benzyl alcohol (and benzaldehyde). Cycloalkanes are also oxidized, in significant (30-40%) yields, to the respective cycloalkanols (and cycloalkanones). Thus, potassium ferrate, used in conjunction with an appropriate heterogeneous catalyst, is a strong and environmentally friendly oxidant.

Ferrate(VI) oxidation of tetrabromobisphenol A in comparison with bisphenol A

“…Diammonium 2,2 0 -azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS, 98%), and humic acid (HA) were purchased from SigmaeAldrich; while montmorillonite K 10 (MMT) was from Acros Organics. Potassium ferrate (Fe(VI), >95%) was prepared by wet chemical synthesis (Delaude and Laszlo, 1996). Buffer chemicals and all other reagents used in the experiments were of analytical grade.…”

Kinetics modeling and reaction mechanism of ferrate(VI) oxidation of benzotriazoles

“…Diammonium 2,2 0 -azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS, 98%) was obtained from Tokyo chemical industry (Shanghai, China). Potassium ferrate (Fe(VI)) was prepared by wet chemical synthesis (Delaude and Laszlo, 1996). It has a purity of above 95% as Fe(VI) (w/w), which was determined by the direct 510 nm method (3 ¼ 1150 M À1 cm À1 ) at the pH value of 9.1 AE 0.1 (5 mM K 2 HPO 4 /1 mM borate) (Rush and Bielski, 1986).…”

Self-Assembled Complexes of Non-cross-linked Amphiphilic Polymeric Ligands with Inorganic Species: Highly Active and Reusable Solid-Phase Polymeric Catalysts

“…Oxidation of Amines Catalyzed by PWAA Since PWAA efficiently promoted the epoxidation of allylic alcohols, we applied this oxidation system to secondary amines. [45][46][47][48][49][50][51][52][53][54][55][56] Oxidation of secondary amines is the most straightforward method and the direct route to prepare nitrones, which are important substrates for the synthesis of nitrogen-containing bioactive compounds. It was beforehand confirmed that no oxidation of dibenzylamine (11a) with hydrogen peroxide was observed at room temperature.…”