Anthracene and related compounds function as lifetime-extending cofactors in the (meso-tetraphenylporphine)Mn(III) chloride-catalyzed epoxidation of olefins. An experiment with a chiral porphyrin catalyst shows that enantioselectivity is preserved in the presence of the cofactor. Additional experiments show that (a) turnover number enhancement is greatest for the least reactive substrates, (b) ...

A novel dioxidomolybdenum complex, [MoO(2)L], derived from the tridentate aroylhydrazone 2-amino-N'-(2-hydroxy-3-methylbenzylidene)benzohydrazide (H(2)L), has been prepared and characterized by elemental analysis, FT-IR, (1)H NMR, and single crystal structural X-ray diffraction. The complex has distorted square pyramidal structure in which the aroylhydrazone ligand behaves as a binegative donor...

Currently, great interest is focused on developing auto-tandem catalytic reactions; a substrate is catalytically transferred through mechanistically distinct reactions without altering any reaction conditions. Here by incorporating a pyrrolidine moiety as a chiral organocatalyst and a polyoxometalate as an oxidation catalyst, a powerful approach is devised to achieve a tandem catalyst for the e...

We describe an inexpensive, low-toxicity and high-yielding method for the production of pure lanosterol and dihydrolanosterol from the commercially available mixture. Optimum conditions are presented for the one-pot production of the intermediate 24,25 vicinal diol of lanosterol acetate (via either epoxidation or hydroxyhalogenation) which is readily separated from the unreacted dihydrolanoster...

The kinetics of cyclooctene epoxidation with H2O2 by micellar catalysis was studied. As catalyst, an ionic liquid (IL) containing the catalytically active tungstate anion used. IL forms micelles in aqueous phase. It is simply formed dissolving sodium and 1-octyl-3-methylimidazolium tetrafluoroborate [OMIM][BF4] H2O2. For catalysis, a power law kinetic model determined that takes critical micell...

Abstract Titanium silicates of MWW structures with different Si/Ti ratios were prepared via hydrothermal synthesis using piperidine as the structure directing agent and boric acid crystallization agent. All syntheses resulted in highly crystalline materials independent ratio. The observed morphology showed MWW-like well-defined thin hexagonal platelets. synthesized Ti-MWW exhibited higher surfa...

R-(+)-limonene epoxidation has been focused from different synthesis methods. Thanks to the optically active epoxides obtained this reaction are widely employed at industrial level, like: agrochemicals, polymers, cosmetics, pharmaceuticals. A key point found in topic asymmetric induction improve yield diastereomers of 1,2-limonene oxide. Many catalysts have developed for diastereoselective epox...

Two resorcinarene-derived tetrathiols with terminal alkene sidechains (tetraarylthiol cavitand 3 and tetrabenzylthiol cavitand 4) were determined to be efficient at extracting colloidal gold nanoparticles from aqueous solutions and stabilizing their dispersion in organic solvents. Treatment of these nanoparticle dispersions with the Grubbs olefin metathesis catalyst resulted in crosslinked reso...