[SbW9O33]-based polyoxometalate combined with a phase transfer catalyst: A highly effective catalyst system for selective oxidation of alcohols with H2O2, and spectroscopic investigation

Recent developments in use of heteropolyacids, their salts and polyoxometalates in organic synthesis

“…IR Studies supported the formation of peroxo intermediate species and also supported the stability of the catalyst in the presence of phase transfer compound under the present experimental condition. The catalyst could be reused after careful decomposition of peroxide of the final reaction mixture[139].…”

Simple and Green Adipic Acid Synthesis from Cyclohexanone and/or Cyclohexanol Oxidation with Efficient (NH4)xHyMzPMo12O40 (M: Fe, Co, Ni) Catalysts

“…It is to highlight that the ammonium salts are not soluble when they are in contact with the substrate (-one, -ol and -one/-ol) and they become soluble after the addition of H2O2 oxidant. Their solubility can be attributed to the formation of metal-peroxo species as it has already been reported by other authors with metal ions with d 0 electronic configuration as: Ti(IV), V(V), and W(VI) [26][27][28]. In this study, the effects of catalyst mass, substrate amount and polyoxometalate composition on the adipic acid yield were examined.…”

“…From obtained results, it can be concluded that the hydrogen peroxide have for role to oxidize the reduced form of POM and simultaneously to form "peroxo-POMox" species as observed with Ti(IV), V(V) and W(VI) metals that have led to metal-peroxo species [26][27][28]. These "peroxo-POMox" species would probably be the active species in the AA formation.…”

Metal–Ligand Cooperation in the Catalytic Dehydrogenative Coupling (DHC) of Polyalcohols to Carboxylic Acid Derivatives

“…It is convenient to use cyclohexanone as a hydrogen acceptor in these reactions because the formation of cyclohexanol is exergonic, and this by-product can be easily recycled with hydrogen peroxide using polytungstate as the catalyst. [18] Moreover, we assume that the finely dispersed droplets of the hydrogen acceptor, cyclohexanone, serve as a solvent for the transition-metal complex in the course of the reaction. Ethylene glycol (8 g) and 1,2-propanediol (8 a), major commodity chemicals from the hydrogenolysis of biodiesel-derived glycerol, are chemoselectively and quantitatively converted to 2-hydroxy acetic acid (10 a, entry 1, Table 3) and 2-hydroxypropionic acid (rac-10 b) [19] in excellent yields after a simple acidic workup of the reaction mixture.…”