Water-soluble polymer anchored peroxotitanates as environmentally clean and recyclable catalysts for mild and selective oxidation of sulfides with H2O2 in water

Selective and Mild Oxidation of 5‐Hydroxymethylfurfural to 5‐Hydroxymethyl‐2‐furancarboxylic Acid over Organic Polymer‐Supported Peroxidoniobium(V) Catalysts

“…The considerable downfield shift, Δδ (δ complex ‐δ free carboxylate )≈34 ppm suggested the presence of strong metal‐ligand interaction in the macromolecular complex [20a,24a,27a] . The observation is in conformity with some other polyacrylate and PMA ‐bound peroxidometal systems reported earlier [23a,27a,c,39b,c] …”

“…The synthetic strategies adopted for preparing the water‐soluble catalyst Nb ‐ PMA and the insoluble catalyst Nb ‐ MRG are summarized in Scheme 2. Utilizing the inherent propensity of water‐soluble polymers (WSP) with pendant ligand groups to bind metal ions, we have earlier devised rather straightforward and facile strategies to incorporate peroxidometal complexes into soluble macromolecular supports [20b,23a,27] . In the present study, the water‐soluble catalyst, Nb ‐ PMA was synthesized by reacting the tetraperoxidoniobium complex Na 3 [Nb(O 2 ) 4 ] (TpNb) with carboxylate containing WSP, poly(sodium‐methacrylate) in presence of hydrogen peroxide, in aqueous medium at neutral pH [(Scheme 2 (a)].…”

Three-Dimensional Graphene Oxide Covalently Functionalized with Dawson-Type Polyoxotungstates for Oxidative Desulfurization of Model Fuels

“…18−21 However, POMs as homogeneous catalysts suffer from the problems of low specific surface area, high solubility in polar solvents, poor stability, and difficult separation and recycling. 22−24 One possible method to overcome these problems is to immobilize POMs on an appropriate support such as mesoporous silica, 25 titanium dioxide, 26 Al 2 O 3 , 27 metal−organic frameworks, 28 polymers, 29 activated carbon, 30 zeolite, 31 ionic liquids, 32 and graphene oxide (GO). 33 GO is a carbon nanomaterial with a 2D layered structure and a high specific surface area, as well as a large number of functional groups such as epoxy, hydroxyl, and carboxyl groups.…”

“…Polyoxometalates (POMs) are a class of inorganic clusters of early transition-metal oxides linked together by one (corner-sharing), two (edge-sharing), or three (face-sharing) oxygen atoms (bridging oxo-groups), and as a result, they have excellent chemical and physical properties such as strong acidity, oxidizability, and photocatalytic activity due to their diverse topological structures and compositions. POMs have been widely used in the catalytic field such as H 2 O 2 -based ODS systems due to simple preparation, high catalytic activity, and environmental friendliness. − However, POMs as homogeneous catalysts suffer from the problems of low specific surface area, high solubility in polar solvents, poor stability, and difficult separation and recycling. − One possible method to overcome these problems is to immobilize POMs on an appropriate support such as mesoporous silica, titanium dioxide, Al 2 O 3 , metal–organic frameworks, polymers, activated carbon, zeolite, ionic liquids, and graphene oxide (GO) . GO is a carbon nanomaterial with a 2D layered structure and a high specific surface area, as well as a large number of functional groups such as epoxy, hydroxyl, and carboxyl groups.…”

Intramolecular benzyl cation transfer in the gas‐phase fragmentation of protonated benzyl phenyl sulfones

“…Sulfones are very important active substances and have been widely used as pesticides, key chemical building blocks, and pharmaceuticals. [1][2][3][4][5][6][7][8] For example, working as an active functional group, the sulfone group are receiving more and more attention in organic synthetic chemistry. 9,10 And among them, benzyl phenyl sulfone is well known as a versatile intermediate in pharmaceutical synthesis.…”