ja972800o_si_001.pdf (253.95 kB)
Download fileEpoxidation by Dimethyldioxirane: Effects of Intramolecular and Intermolecular Interactions
journal contribution
posted on 1998-03-04, 00:00 authored by Karol Miaskiewicz, Douglas A. SmithThe Density Functional Theory B3LYP/6-31G* method is
used to provide a detailed understanding
of the origins of intra- and intermolecular (solvent) effects on the
epoxidation of C−C double bonds by
dimethyldioxirane (DMDO) in a model system, 2-methyl-2-butene. We
found that the presence of hydrogen
bond donor substituents, such as hydroxyl and amino groups, at the
allylic position on the olefin leads to
substantially decreased activation barriers for epoxidation. This
effect is observed exclusively when a hydrogen
bond interaction is present between the hydroxyl or amino substituent
and the attacking DMDO molecule, and
is not caused by inductive electronic effects of the substituents.
An even more significant lowering of the
activation barrier is seen when DMDO forms a hydrogen bond with
methanol (representing a hydrogen bond
donor solvent) in the transition state. Solvent polarity, studied
using the SCIPCM model, influences the
epoxidation barrier to a much smaller degree than do hydrogen bonding
interactions.
History
Usage metrics
Read the peer-reviewed publication
Categories
Keywords
hydrogen bond donoractivation barriershydrogen bond donor substituentsepoxidation barrierSolvent polarityDMDO moleculeSCIPCM modeltransition stateactivation barrierhydrogen bond interactionIntermolecular InteractionshydroxylDMDO formsmodel systemDensity Functional Theory B 3LYP methodhydrogen bondallylic position