The first stable bromoallene oxides were obtained by the DMDO epoxidation of 1-bromo-1,3-di-tert-alkylallenes, producing the first crystalline allene oxide of any kind. The epoxidations are regioselective for the bromine-bearing Δ1,2 alkene, and also face selective producing single diastereomer E-olefin products.

A study, via isotopic labeling, of the stereoselective processes in a Shi-type epoxidation, has revealed that the chiral platform provided by the catalyst mediates the transfer of the pro-S "O" of the related dioxirane species to the alkene in a doubly stereoselective manner.

Homogeneous linear poly(tartrate ester) ligands provide high chemical yields and enantiomeric excesses in the epoxidation of trans-hex-2-en-1-ol using Ti(OPr)4-tert-butyl hydroperoxide. Branched poly(tartrate ester) can be use as heterogeneous ligands in the epoxidation of trans-hex-2-en-1-ol using Ti(OPr)4-tert-butyl hydroperoxide. Removal and recovery of the polymer catalyst is a simple filtr...

Alkene selective oxidation is of major technological importance since alkene epoxides are versatile chemical intermediates used in the manufacture of a wide range of commodity and fine chemicals. The reaction itself is mechanistically very interesting and it has attracted a lot of the academic interest over many years. Various models have been proposed in order to explain why the reaction is ap...

Herein, an efficient epoxidation of 1-nonene is described. In a simple epoxidation system, commercially available Novozym 435, an immobilized Candida antarctica lipase B, and hydrogen peroxide (H(2)O(2)) were utilized to facilitate the in situ oxidation of phenylacetic acid to the corresponding peroxy acid which then reacted with 1-nonene to give 1-nonene oxide with high yield and selectivity....

A new heterogeneous catalytic system, phase-boundary catalysis, for epoxidation of alkene with aqueous H2O2 is proposed. Amphiphilic titanium-loaded zeolite particles, a part of the external surface of which was covered with hydrophobic alkyl groups and the rest being left hydrophilic, were prepared by deposition of titanium species from titanium(IV) tetra-2-propoxide and attachment of octadecy...

We report the development of a tandem chemoenzymatic transformation that combines alkene metathesis with enzymatic epoxidation to provide aryl epoxides. The development of this one-pot reaction required substantial protein and reaction engineering to improve both selectivity and catalytic activity. Ultimately, this reaction converts a mixture of alkenes into a single epoxide product in high ena...

Vegetable oils have different unique properties owing to their unique chemical structure. Vegetable oils have a greater ability to lubricate and have higher viscosity indices. Therefore, they are being more closely examined as base oil for biolubricants and functional fluids. In spite of their many advantages, vegetable oils suffer from two major drawbacks of inadequate oxidative stability and ...