Epoxidation of Lower Olefins with Hydrogen Peroxide and Titanium Silicalite

Abstract The epoxidation of lower olefins, catalysed by titanium silicalite (TS-1) under mild conditions, is reported. The reaction may be performed at near room temperature, in dilute alcoholic or aqueous solutions of hydrogen peroxide. In methanol C 4 -C 8 linear olefins, allyl chloride, and allyl alcohol show fast reaction rates and high selectivities (72-97% on H 2 O 2 ). The solvolysis of the oxirane ring and the oxidation of the solvent are the main side reactions. Yields and kinetics are decreased by increasing the chain length or the cross-section of the olefin ( n -C n > n -C n +1 , 1-hexene ⪢ cyclohexene), by electron-withdrawing substituents (1-butene > allyl chloride > allyl alcohol), and by solvents in the order methanol > ethanol > t -butanol. The rate of reaction also depends on the position and steric configuration of the double bond and on the branching, as a result of inductive and shape selectivity effects: trans 2-butene cis 2-butene, 2-methyl-1-butene