carbodiimides in hydroxylic solvents containing hydrogenperoxide with mildly basic or acidic catalysts have been found to promote the epoxidation of olefins. A commercially available 30% aqueous solution of hydrogenperoxide serves as the oxidant for this process. The presumed reactive species is a peroxyisourea generated in situ by the addition of hydrogenperoxide to the carbodiimide.
Used in combination with the Sharpless asymmetric epoxidation of allylicalcohols, this rearrangement represents a new approach to the synthesis of various opticallyactive β-hydroxy aldehydes, useful intermediates in natural product synthesis. The modified organoaluminum reagent, MABR is also applicable to the transformation of a variety of simple epoxides to carbonyl compounds with high efficiency
An efficient biomimetic Fe-catalyzed epoxidation of olefins using hydrogen peroxide
作者:Gopinathan Anilkumar、Bianca Bitterlich、Feyissa Gadissa Gelalcha、Man Kin Tse、Matthias Beller
DOI:10.1039/b612048b
日期:——
environmentally benign and practical epoxidation method was developed using inexpensive and efficient Fe catalysts. FeCl3.6H2O in combination with commercially available pyridine-2,6-dicarboxylic acid and amines showed excellent reactivity and selectivity towards aromatic olefins and moderate reactivity towards 1,3-cyclooctadiene utilizing H2O2 as the terminal oxidant.
The combination of iron(III) chloride, pyridine‐2,6‐dicarboxylic acid and formamidine ligands allows for the epoxidation of styrenes and conjugated dienes in excellent chemoselectivity and yields.
A hydrazone Schiff base ligand derived from salicylaldehyde and benzhydrazide has been synthesized and reacted with vanadium(IV) leading to the corresponding vanadium(V) complex. The complex has been anchored on the surface of functionalized silica gel by N,O-coordination to the covalently Si–O bound modified salicylaldiminato ligand. The supported complex has been evaluated as a catalyst for hydrocarbon