Studies on the structural change of a reaction-controlled phase-transfer [π-C5H5NC16H33]3{PO4[WO3]4} catalyst during the selective oxidation of cyclopentene to glutaric acid with aqueous H2O2

The primary stages of polyoxomolybdate catalyzed cyclohexanone oxidation by hydrogen peroxide as investigated by in situ NMR. Substrate activation and evolution of the working catalyst

“…Such results are fully consistent with progressive decomposition of the Keggin POM in presence of hydrogen peroxide and formation of novel peroxo complexes as discussed in the literature[24,53,55]. Nonetheless, peroxo tungstate complexes also showed ability to transform into Keggin derivative during oxidation of cyclopentene with aqueous H 2 O 2[56]. This would indicate reversible structural rearrangement of the catalyst during the catalytic processes.…”

Phase-transfer hydroxylation of benzene with H2O2 catalyzed by a nitrile-functionalized pyridinium phosphovanadomolybdate

“…1 Great efforts have been made to achieve the catalytic phase-transfer system, such as esterification, 2 oxidative esterification, 3 carbonylation, 4 Stetter reaction, 5 etc. In particular, polyoxometalate (POM) hybrid-catalyzed H 2 O 2 -based organic oxidations have been revealed as the phase-transfer reactions for the oxidation of olefins 6,7 and alcohols. 8,9 Owing to the versatility of POM chemistry, 10,11 it is very interesting to design novel and efficient POM-based catalysts for more organic phase-transfer transformation processes.…”

Epoxidation of Soybean Oil Catalyzed by [π-C5H5NC16H33]3[PW4O16] with Hydrogen Peroxide and Ethyl Acetate as Solvent

“…A broad peak from 0 to -15.0 ppm was observed in the 31 P MAS NMR spectrum of I, as shown in Figure 3(A(a)). Based on the results of the literatures [10,11], it can be attributed to heteropoly tungstophosphates with ratio of (A) (B) P/W from 1/2 to 1/12, indicating that I was a mixture with different P/W ratios. The highest peak at 6.2 ppm might be due to species with high P/ W ratio [10,11].…”