Sustainable Oxidation of Cyclohexane and Toluene in the Presence of Affordable Catalysts: Impact of the Tandem of Promoter/Oxidant on Process Efficiency.

The oxygenation of cyclohexane and toluene by O and HO catalyzed by VO(acac) and Co(acac) was studied at 40-100 °C and 1-10 atm. Upon such conditions, the process can be remarkably (30× times) enhanced by the minute (6-15 mM) additives of oxalic acid (H) or -hydroxyphthalimide (NHPI). The revealed effect of H on HO-piloted oxidation is closely associated with the nature of the catalyst cation and boosted by VO(acac).

Sustainable oxidation of cyclohexane catalyzed by a VO(acac)-oxalic acid tandem: the electrochemical motive of the process efficiency.

Cyclohexane oxidation by HO to cyclohexanol, cyclohexanone, and cyclohexylhydroperoxide under mild (40 °C, 1 atm) conditions is significantly enhanced in the system composed of VO(acac) (starting catalyst) and small additives of oxalic acid (process promoter). In corroboration of this, several times higher yield of the desired products was obtained compared to that obtained in the acid-free process. The revealed advantage was addressed to elevate the electrical conductance (or , decreasing the resistance, 1/) of the reaction medium.

Substrate-triggered activation of a synthetic [Fe2(μ-O)2] diamond core for C-H bond cleavage.

An [Fe(IV)(2)(μ-O)(2)] diamond core structure has been postulated for intermediate Q of soluble methane monooxygenase (sMMO-Q), the oxidant responsible for cleaving the strong C-H bond of methane and its hydroxylation. By extension, analogous species may be involved in the mechanisms of related diiron hydroxylases and desaturases. Because of the paucity of well-defined synthetic examples, there are few, if any, mechanistic studies on the oxidation of hydrocarbon substrates by complexes with high-valent [Fe(2)(μ-O)(2)] cores.