V(IV)-catalyzed cyclohexane oxygenation promoted by oxalic acid: Mechanistic study

Sustainable oxidation of cyclohexane catalyzed by a VO(acac)2-oxalic acid tandem: the electrochemical motive of the process efficiency

“…More rationales concerning the mechanism of the revealed features were reported earlier. 14 In order to evaluate the impact of cation nature, C 6 H 12 oxidation was also carried out in the presence of Co(acac) 2 ( Table 1, entries 9-11). For this catalyst, whether oxalic acid was present in the initial reaction solution or not, the set of products (COL, CON, and CHHP) remained the same as in case of VO(acac) 2 .…”

“…The detailed description of application GLC, impedance, CV, pH, and iodometric methods has been provided earlier. 14,17…”

“…Visually, it is reected by the almost instant replacement of the blue color of the initial VO 2+ solution (l max z 400 nm) by the yellow color of the VO 2 + species (l max ¼ 460 nm) once H 2 O 2 was added. 14…”

“…Inspired by the cited studies, we scrutinized the activation abilities of glyoxal as a simpler analog of butanedione where CH 3 -groups are substituted by H-atoms. 12 On the other hand, since oxalic acid (OxalH) was the product of glyoxal oxidation, 14 its potential impact on the studied process was also investigated. As revealed, the yield of the products can be sufficiently improved by application of the VO(acac) 2 catalyst together with OxalH.…”

“…Among others, it leads to the species composed of the VO(h 2 -O) 2 core, which manifests itself as a selective (contrary to the free radicals) and active oxygenation agent. 14 Most previously undertaken studies involve traditional chemical approaches to assess the enhancing effect of catalysts and additives on the process efficiency. On the other hand, the literature that elucidates the impact of electrochemical parameters on the process, apart from cyclic voltammetry (CV) studies, remains rather short and covers pure solvents only.…”