Organic Solvent-free Conditions Research Articles

Water-Soluble Salicylaldiminato Ni(II)−Methyl Complexes: Enhanced Dissociative Activation for Ethylene Polymerization with Unprecedented Nanoparticle Formation

Water-soluble single-component (kappa2-N,O)-salicylaldiminato nickel-methyl complexes 1-4-L (L = TPPTS, TPPDS, H2N-PEG-OMe) allow for the catalytic polymerization of ethylene under organic solvent-free aqueous conditions producing high molecular weight polyethylene with particle sizes below 10 nm. Amphiphilic TPPDS- and H2N-PEG-OMe complexes exhibit a polymerization activity in water higher than that in toluene. A solvation-favored activation of precatalysts 1-4-L by equilibrium dissociation of L in aqueous solution likely accounts for this enhanced polymerization activity. The observed generation of a given particle by a single active site is an unprecedented mechanism for formation of aqueous particle dispersions.

Highly efficient and selective oxidation of secondary alcohols to ketones under organic solvent and transition metal free conditions

The aqueous HBr/H 2 O 2 was found to be highly efficient and green catalytic system for the selective oxidation of the secondary alcohols to ketones in excellent yields under organic solvent free conditions. The results of the oxidation of the secondary alcohols with solid alternatives of the aqueous hydrogen peroxide like SPC or SPB are also described.

Catalysis by Ionic Liquids: Cyclopropyl Carbinyl Rearrangements Catalyzed by [pmim]Br under Organic Solvent Free Conditions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Catalysis by ionic liquids: cyclopropyl carbinyl rearrangements catalyzed by [pmim]Br under organic solvent free conditions

Aryl substituted cyclopropyl carbinol derivatives undergo stereoselective rearrangements catalyzed by the ionic liquid, 1-methyl-3-pentylimidazolium bromide, under sonication, without any organic solvent, to produce the substituted conjugated all- trans-butadienes.

Oxidation of alcohols with H 2O 2 catalyzed by bis-quaternary phosphonium peroxotungstates (or peroxomolybdates) under halide- and organic solvent-free condition

Several novel kinds of bis-quaternary phosphonium salts of peroxotungstate and peroxomolybdate, such as Ph 3P(CH 2) 2PPh 3[W(O 2) 4]·2H 2O, Ph 3P(CH 2) 2PPh 3[WO(O 2) 2(C 2O 4)]·2H 2O, Ph 3P(CH 2) 3PPh 3[W(O 2) 4]·2H 2O, and Ph 3P(CH 2) 2PPh 3[MoO(O 2) 2(C 2O 4)]·2H 2O, have been synthesized and characterized by elemental analysis, IR and Raman spectroscopy. Their catalytic properties in oxidation of cyclohexanol and benzyl alcohol to cyclohexanone, benzaldehyde or benzoic acid were investigated with aqueous 30% hydrogen peroxide under halide- and organic solvent-free conditions. The results show that the bis-quaternary phosphonium peroxotungstates have excellent catalytic ability to the oxidation reaction of benzyl alcohol and cyclohexanol by hydrogen peroxide. The Mo(IV) analog peroxo complexes were less active than peroxotungstates. The maximum yields of benzaldehyde, benzoic acid and cyclohexanone can be reached 93.89%, 88.87%, and 92.70%, respectively.

An Assembled Complex of Palladium and Non‐Cross‐Linked Amphiphilic Polymer: A Highly Active and Recyclable Catalyst for the Suzuki—Miyaura Reaction.

AbstractFor Abstract see ChemInform Abstract in Full Text.

An assembled complex of palladium and non-cross-linked amphiphilic polymer: a highly active and recyclable catalyst for the Suzuki-Miyaura reaction.

An insoluble and assembled catalyst of palladium and a non-cross-linked amphiphilic polymer were developed. In the presence of 50-500 ppm mol equiv of catalyst, the Suzuki-Miyaura reaction proceeded efficiently under organic solvent-free conditions. The catalyst was reused 10 times without any decrease in activity and was recycled without any special treatment.[structure: see text]

Oxidation of benzyl chlorides and bromides to benzoic acids with 30 hydrogen peroxide in the presence of Na(2)WO(4), Na(2)VO(4), or Na(2)MoO(4) under organic solvent-free conditions.

Oxidation of benzyl chlorides and bromides to benzoic acids with 30 hydrogen peroxide in the presence of Na(2)WO(4), Na(2)VO(4), or Na(2)MoO(4) under organic solvent-free conditions.

The salicylates. XIX. The question of acidosis following the administration of salicylates: Johnson, Charles C.: J. A. M. A. 94: 784, 1930

Molybdenum complexes with ONO tridentate Schiff base ligands based on salicylideneaminophenolato (SAP) backbone with OH substitution on the salicyl arene ring have been synthesized and characterized. The molecular structures of the full series of OH substituted molybdenum complexes were determined by X-ray crystallography as monomers stabilized by one solvent molecule, [MoO2L(D)]. All dimeric complexes [MoO2L]2 were tested for the epoxidation of cyclooctene and cyclohexene under organic solvent-free conditions using aqueous TBHP as oxidant. The position of the OH on the SAP-modified ligand influenced the catalytic activity of the respective complexes. DFT calculations for the catalytic cycle yield energy spans in agreement with the experimentally observed activity trend.