Epoxidation of lower olefins with hydrogen peroxide and titanium silicalite

Journal Article · Mon Mar 01 04:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1069· OSTI ID:7369081

Clerici, M G; Ingallina, P ^[1]

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1. Eniricerche SpA, Milano (Italy)

The epoxidation of lower olefins, catalyzed 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[sub 4]-C[sub 8] linear olefins, allyl chloride, and allyl alcohol show fast reaction rates and high selectivities (72-97% on H[sub 2]O[sub 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[sub n] > n-C[sub n+1], 1-hexene [much gt] 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 < iso-butene < 1-butene < cis 2-butene, 2-methyl-1-butene < 1-pentene, and 3-methyl-1-butene < 2-methyl-1-butene < 2-methyl-2-butene. The epoxidation occurs with retention of configuration. Basic compounds at low concentration do not slow the kinetics, but do improve significantly the yields, up to 97% in the epoxidation of 1-butene. At higher concentrations, TS-1 activity is decreased and eventually inhibited by bases. No effect on kinetics is exerted by tetrapropylammonium hydroxide. Catalytic activity is improved by acids. A heterolytic peracid-like mechanism is envisaged in the oxygen-transfer step. A five-membered cyclic structure, formed by a titanium hydroperoxo moiety Ti-OOH, and a protic molecule ROH at Ti sites, is proposed as the active species. 41 refs., 5 figs., 4 tabs.

• OSTI ID: 7369081
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 140:1; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical &amp; Physicochemical Properties
ALCOHOLS
ALKENES
AQUEOUS SOLUTIONS
BASES
CATALYSIS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
DECOMPOSITION
DISPERSIONS
ELEMENTS
ETHANOL
HALOGENATED ALIPHATIC HYDROCARBONS
HETEROGENEOUS CATALYSIS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
HYDROXY COMPOUNDS
KINETICS
METHANOL
MIXTURES
NONMETALS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDATION
OXYGEN
OXYGEN COMPOUNDS
PEROXIDES
REACTION KINETICS
RETENTION
SILICATES
SILICON COMPOUNDS
SOLUTIONS
SOLVENTS
SOLVOLYSIS
TITANIUM COMPOUNDS
TITANIUM SILICATES
TRANSITION ELEMENT COMPOUNDS
YIELDS