Highly efficient triphenyl(3-sulfopropyl)phosphonium functionalized phosphotungstic acid on silica as a solid acid catalyst for selective mono-allylation of acetals

Abstract

Silica supported phosphotungstic acid functionalized with triphenylIJ3-sulfopropyl)phosphonium (PW-Si/ TPSP) was developed as a solid acid catalyst for C-C bond formation via Hosomi-Sakurai allylation of acetals. Functionalization of PW as well as its binding to silica was confirmed by solid state 31 P-NMR and 29 Si-NMR, respectively. Among the various catalysts prepared, the 30% PW loaded (30PW-Si/TPSP) catalyst gave an excellent yield of homoallyl ethers (HAEs) via selective mono-allylation of acetals with allyltrimethylsilane. A plausible reaction pathway has also been proposed in which the strong Brønsted acid sites of 30PW-Si/TPSP play an important role in activating the acetals to form the corresponding oxonium cations. The versatility of our catalyst was demonstrated for the allylation of a wide variety of acetals while its stability was established in five successful recycling runs.

Self-Solidifying Quaternary Phosphonium-Containing Ionic Liquids as Efficient and Reusable Catalysts for Biodiesel Production

“…For TTMPP-PS (Figure 3a), the bands at 1594 and 1459 cm −1 are attributed to phenyl group vibrations, 45 while the band at approximately 1230 cm −1 is assigned to the aromatic ether group vibration. 46 The bands at 947 and 915 cm −1 are caused by the characteristic vibrations of quaternary phosphonium groups, 47 51 These results indicate that TTMPP-containing ionic liquids were synthesized successfully and are consistent with the NMR spectra results.…”

“…From TTMPP-PS to the TTMPP-containing ILs, newly formed characteristic bands can be clearly observed. Specifically, for [TTMPP-PS]­[HSO 4 ] (Figure b), the presence of HSO 4 – anions can be confirmed by the band at 867 cm –1 ; for [TTMPP-PS]­[CF 3 SO 3 ] (Figure c), the presence of CF 3 SO 3 – anions can be confirmed by the band at 635 cm –1 ; and for [TTMPP-PS] 3 [PW 12 O 40 ] (Figure d), the presence of PW 12 O 40 3– anions can be confirmed by the bands at 804, 893, 976, and 1078 cm –1 . These results indicate that TTMPP-containing ionic liquids were synthesized successfully and are consistent with the NMR spectra results.…”

Tandem Conversion of Fructose to Bio‐diketones Using a Multifunctional Pd‐POPs‐CF3SO3H Catalyst

“…In the 31 P SS NMR spectra (Figure 2c), a signal ascribed to triphenylphosphine appeared at −4.1 ppm for all the samples. According to the literature, the broad signal at ~24 ppm (23.3, 24.5, and 24.3 ppm for Pd‐POPs‐CF 3 SO 3 H, Pd‐POPs‐H 3 PO 4 , and Pd‐POPs‐HCl, respectively) corresponds to quaternary phosphonium, [22] with the difference in anions leading to the deviation in chemical shift. A signal appeared at 0.8 ppm in the spectrum of Pd‐POPs‐H 3 PO 4 , indicating the presence of PO 4 3+ .…”

Conversion of bare corn cobs waste into sustainable and ecofriendly nanobiosorbent for effective removal of cationic basic fuchsin and methylene blue dyes from water

“…Additionally, The HR-TEM image of BCCW-NB nanobiosorbent is illustrated in Figure 1c and show some sort of aggregation of the nanobiosorbent with an average particle size about 17 nm [43]. The XRD pattern of BCCW-NB nanobiosorbent (Figure 1d) shows the obvious amorphous structure of this material with a broad hump ranging from 15-30 o attributed to aromatic carbon, in addition to small peak at 26.1 o indicating presence of SiO2 [44]. The thermal stability and weight loss of BCCW-NB nanobiosorbent is illustrated via TGA (Figure 1e) to demonstrate the loss of adsorbed moisture around 100 ᴏ C followed by a significant mass loss at 275-528 o C due to the degradation of cellulose and hemicellulose moieties, aromatization of char and slow degradation of the remaining lignin [45].…”