Mechanistic studies of the pathways leading to ethers via coupling of alcohols
- Zettlemoyer Center for Surface Studies, Bethlehem, PA (United States)
The reaction mechanisms for the solid acid-catalyzed dehydrative coupling of methanol and ethanol with isobutanol and 2-pentanol to form ethers were examined by using isotope labelling and chiral inversion experiments. When the reactions were carried out it 110{degrees}C and 1 MPa with {sup 18}O-ethanol and {sup 16}O-isobutanol over the Amberlyst-35 resin catalyst, 95% of the major product ethyl isobutyl ether (EIBE) contained {sup 16}O, while 96% of the minor product ethyl tertiarybutyl ether (ETBE) contained {sup 18}O. Similar results were obtained with methanol and isobutanol over Nafion-H and Amberlyst-35 catalysts, with methyl isobutyl ether (MIBE) and methyl tertiarybutyl ether (MTBE) as the products. These results indicate that EIBE (MIBE) was produced by a surface-catalyzed S{sub N}2 reaction, while the ETBE (MTBE) product arose via a carbenium intermediate. The analogous reaction carried out over Nafion-H and HZSM-5 catalysts with chiral 2-pentanol verified the surface-mediated S{sub N}2 reaction, wherein chiral inversion of the product ether was observed relative to the S- and R-2-pentanol reactants.
- OSTI ID:
- 433265
- Report Number(s):
- CONF-950402-; ISSN 0569-3772; TRN: 97:000007-0028
- Journal Information:
- Preprints of Papers, American Chemical Society, Division of Fuel Chemistry, Vol. 40, Issue 1; Conference: 209. American Chemical Society (ACS) national meeting, Anaheim, CA (United States), 2-6 Apr 1995; Other Information: PBD: 1995
- Country of Publication:
- United States
- Language:
- English
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