There is a great demand for development of catalyst systems that are not only efficient and highly enantioselective but are also environmentally benign. Herein we report investigations into the catalytic asymmetric addition of alkyl and functionalized alkyl groups to ketones under highly concentrated and solvent-free conditions. In comparison with standard reaction conditions employing toluene ...

A practical method for the multigram scale selective cis-dihydroxylation of electron deficient alkenes such as diethyl fumarate and N-alkyl and N-aryl-maleimides using H(2)O(2) is described. High turnovers (>1000) can be achieved with this efficient manganese based catalyst system, prepared in situ from a manganese salt, pyridine-2-carboxylic acid, a ketone and a base, under ambient conditions....

The Jacobsen catalyst, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminomanganese (III) chloride is covalently immobilized on mesoporous phenolic resin through a direct and simple procedure. The immobilization is evident from nitrogen sorption and quantitative XRF measurements. A complex loading of 0.09 mmol/g is obtained, corresponding to well dispersed Mn-complexes on the surface...

Amino-functionalised metal-organic frameworks UiO-66 and -67 were post-synthetically modified with salicylaldehyde. A molybdenum complex was immobilised on the resulting materials. They were characterised by (13)C-MAS-NMR, XPS and PXRD to confirm immobilisation and stability. The immobilised complex is an active and reusable catalyst for olefin epoxidation with tert-butyl hydroperoxide (TBHP) a...

Gold-titania based catalysts for the direct epoxidation of propene provide a clean and simple route for future propene oxide producing processes. These catalysts, producing propene oxide in a single step, have a moderate activity and a very high selectivity towards propene oxide. However, the hydrogen, which is used as a co-reactant, is used less efficient. To be able to improve the hydrogen ef...

Cobaltabis(dicarbollide), Na[3,3?-Co(?5-1,2-C2B9H11)2] Na[1]), is an efficient photoredox catalyst for the epoxidation of alkenes in water, at low loading and requiring short reaction times (15–30 min).

The new heterogeneous catalyst based on MoO2(acac)2 immobilized on superparamagnetic nanoparticle functionalized with dendrimer was synthesized. The dendrimer with amine and sulfur functional groups offer proper positions for a strong connection between MoO2(acac)2 and support. The synthesized catalyst was characterized by FT-IR spectroscopy, ICP, TGA, SEM, TEM, and XRD. This catalyst showed hi...

The oxidation of C-H, C-C and C=C of hydrocarbons, from the syntheses of many fine chemicals to the manufacture of various commodities in large scale, plays great important role in transformation of basic materials to useful synthetic building in organic chemistry and in conversion of hydrocarbon to oxygen-containing industrial production especially the hydroxylation, epoxidation, degradation o...

[Mo(O)(O(2))(2)(L)(2)] compounds (L = pz, pyrazole; dmpz, 3,5-dimethylpyrazole) were reacted stoichiometrically, in the absence of an oxidant, with cis-cyclooctene in an ionic liquid medium where selective formation of the corresponding epoxide was observed. However, this oxo-transfer reaction was not observed for some other olefins, suggesting that alternative reaction pathways exist for these...

Cooperativity between Brønsted acidic defect sites on oxide surfaces and Lewis acid catalyst sites consisting of grafted calixarene-Ti(IV) complexes is investigated for controlling epoxidation catalysis. Materials are synthesized that, regardless of the surface or calixarene substituent, demonstrate nearly identical UV-visible ligand-to-metal charge-transfer bands and Ti K-edge X-ray absorption...