Catalytic performance of binary and ternary oxovanadium complexes of dipyridinyl-urea in (ep)oxidation of cis-cyclooctene and 1-octene

Abstract

Two novel ternary and binary mono-oxovanadium(IV) complexes of acetylacetonate (ac) and 1,3-dipyridin-2-yl-urea are synthesized, as VO(acac)(L) (1:1) and VO(L)2 (1:2). They are characterized by various physico-chemical spectroscopic tools. The formation constants Kf are calculated from the spectrophotometric measurements. The catalytic potential of VO(acac)(L) and VO(L)2 has been examined in the (ep)oxidation of alkenes (cis-cyclooctene and 1-octene) by an aqueous hydrogen peroxide, H2O2, and tert-butyl hydroperoxide, TBHP. The effects of temperature, solvent and oxidant/alkene molar ratio are studied in order to get the optimized reaction conditions. Most of the catalytic (ep)oxidation products of cis-cyclooctene and 1-octene are determined qualitatively and quantitatively using gas chromatographic analysis. The increase of the catalyst amount to double time reduces the (ep)oxidation process time with improvement of the amount of the chemoselective epoxy product.