Quaternary ammonium tetrakis(diperoxotungsto)phosphates(3-) as a new class of catalysts for efficient alkene epoxidation with hydrogen peroxide

Influence of composition of heteropolyphosphatotungstate catalyst on epoxidation of propylene

“…δ = 5 ppm all appear obviously, which corresponds to a heteropolyphosphatotungstate structure entity with low W/P ratio. The catalyst A is obtained by distillating solvent in a water bath at 60 • C, not by gently evaporating solvent under reduced pressure at 40-50 • C as described by Venturello et al [2], so it is inevitably that the peroxo bond O-O of catalyst A is broken up in the distillation step, leaving behind a mixture of many heteropolyphosphatotungstates with different P/W composition, whose overall composition are [-C 5 H 5 NC 16 H 33 ] 3 [PW 4 O 16 ]. Because of the individual amounts of heteropolyphosphatotungstates are all small except the specie with 31 P MAS NMR band at ca.…”

“…In 1983, Venturello et al [1,2] proposed that the complex consisting of tungstate and phosphate can catalyze the epoxidation of different alkenes with dilute H 2 O 2 solution (15%) as oxidant. In 1988, Ishii et al [3] proposed that the system composed of H 3 PW 12 O 40 and cetylpyridinium chloride can catalyze epoxidation of alkenes with commercially available H 2 O 2 solution as oxidant.…”

Comparison of the methods of the phase transfer catalysis and hydroperoxide in the epoxidation of 1,5,9-cyclododecatriene

“…The changes of the Mo(CO) 6 :TBHP mole ratio in the range 0.0001 -0.001 do not have a significant influence on the yield of the ECDD.…”

Peroxopolyoxotungsten-based Ionic Hybrid as a Highly Efficient Recyclable Catalyst for Epoxidation of Vegetable oil with H2O2

“…The catalysts were prepared according to Venturello et al 24 A suspension of tungstic acid (2.50 g, 10 mmol) in 7 mL of 30% (w/v) aqueous H 2 O 2 was stirred and heated at 60°C until a colorless solution was obtained. After filtering and cooling the solution at room temperature, 40% (w/v) H 3 PO 4 (0.62 g, 2.5 mmol) was added and the solution was diluted with 30 mL of water and then stirred for 30 min.…”