Preyssler catalyst: An efficient catalyst for esterification of cinnamic acids with phenols and imidoalcohols

Preyssler catalyst-promoted rapid, clean, and efficient condensation reactions for 3H-1,5-benzodiazepine synthesis in solvent-free conditions

“…The Preyssler heteropolyanion was prepared from Na 2 WO 4 acidic characteristic of this catalyst using potentiometric tritration. 27 The maximum acid strength of the acid sites (E) for the catalyst is 862 mV. This E value indicates very Brönsted strong acid sites for the catalyst, and it was similar to the obtained for bulk commercial Keggin HPA.…”

“…Among the various possible HPA structures, the Keggin-type primary structure deserves to be mentioned, due to its widely reported applications. 24 As part of a research project to develop environmentally friendly organic reactions, we used bulk or silica-supported heteropolyacids with Preyssler structure as recyclable catalyst in the solvent-free synthesis of flavones, 25 Nsulfonyl-1,2,3,4-tetrahydroisoquinolines, 26 phenyl cinnamates, 27 and 1,1-diacetates 28 to name some examples.…”

“…the previously reported method, and converted to the corresponding acid H 14 [NaP 5 W 30 O 110 ] by passing it through a Dowex-50-X8 ion-exchange column 27. The HPA catalyst was characterized by 31 P MAS-NMR and FT-IR spectroscopy 32.…”

A novel magnetic Preyssler acid grafted chitosan nano adsorbent: synthesis, characterization and adsorption activity

“…24 As indicated in Fig. 1(c), the characteristic bands of Preyssler structure are three bands due to P-O stretching at 1163, 1080 that are consistent with a C 5V symmetry anion and 1020 cm −1 , and two bands attributed to W-O-W at 940 and 905 cm −1 , a band at 695 cm −1 corresponding to W = O 25,26 and band at 560 cm −1 due to P-O bending.…”

Molecular structure, experimental and theoretical1H and13C NMR chemical shift assignment of cyclic and acyclic α,β-unsaturated esters

“…The phenyl cinnamates investigated in this study were obtained using some modified methods from phenols and cinnamic acids, and 4‐methyl coumarins were prepared from O ‐allylation of 7‐hydroxy‐4‐methylcoumarin and subsequent Claisen rearrangement of the products …”