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Efficient Protection of Alcohols with Carboxylic Acids Using a Variety of Heteropolyoxometallates as Catalysts, Studying Effective Reaction Parameters

“…In continuation of our ongoing research program on using heteropolypolyoxometallates in organic synthesis, [17][18][19][20][21][22][23][24][25][26][27] herein, we wish to report a simple, efficient, selective, and general method for the protection of some alcohols by the mediation of some heteropoly compounds at room temperature or under reflux conditions. The reactions were carried out in good yields within quite short reaction times.…”

Heteropolyacids as an efficient and reusable catalytic system for the regiospecific nitration of phenols with metal nitrates

“…However, because the metal substitution may modify the energy and composition of the LUMO and redox properties, for mentioned heteropolyacids with different charges, the energy and composition of the LUMOs have significant effects on the catalytic activity [58]. Substitution of vanadium ions into the molybdenum framework stabilize the LUMOs because these orbitals derive, in part from vanadium d-orbitals which have been assumed to be more stable than those of molybdenum and tungsten [59].…”

Novel oxidation of aromatic aldehydes catalyzed by Preyssler's anion, [NaP5W30O110]14-

“…Some important features of this polyanion are: stability in the pH range from 0 to 12, thermal stability, rendering high temperature reactions possible, and easy recovery of both pure and supported catalysts. 17 In continuation of our research on the syntheses and application of heteropolyacids in organic syntheses, [17][18][19][20][21][22] and due to the importance of derivatives of benzoic acid in medicine and industry, we hereby report the applicability of Preyssler's anion for efficient oxidation of aromatic aldehydes to the corresponding carboxylic acids. The major aim of the work described herein "is the design and development of applications for Preyssler's catalyst".…”

“…This behavior is in accordance with our previous results of esterification reactions. 20,22 Also our data show that, while in most reactions, benzaldehydes with electron-withdrawing substituents are thought to be hard-oxidising aldehydes, in the presence of Preyssler's catalyst, product yields are highest with electron-withdrawing substituents. 17 The silica gel powder with mean particle size 15 μm was purchased from Merck Company and was used as the catalyst support.…”