Premium
Investigating Solvent Effects of an Ionic Liquid on Pericyclic Reactions through Kinetic Analyses of Simple Rearrangements
Author(s) -
Keaveney Sinead T.,
Haines Ronald S.,
Harper Jason B.
Publication year - 2017
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.201600585
Subject(s) - solvophobic , chemistry , ionic liquid , solvation , solvent , pericyclic reaction , solvent effects , reaction coordinate , acetonitrile , ionic bonding , claisen rearrangement , computational chemistry , photochemistry , organic chemistry , catalysis , ion
Abstract Simple Cope and Claisen rearrangements were investigated in an ionic liquid and a range of molecular solvents through a series of kinetic studies. Analysis of the solvent effects on the Cope rearrangement of 3‐phenyl‐1,5‐hexadiene indicated that a solvophobic effect was responsible for the observed rate enhancement in the ionic liquid, and that this was due to preferential solvation of the transition state. A similar solvophobic effect contributes to the ionic liquid solvent effect on the Claisen rearrangement of allyl vinyl ether, although the ability of the ionic liquid to stabilise the incipient charges in the transition state also likely contributes to the rate increase observed in the ionic liquid solvent. The activation parameter data suggest that in this case the ionic liquid was interacting with species along the reaction coordinate through general coulombic interactions (more acetonitrile‐like) rather than through hydrogen‐bonding interactions (less ethanol‐like).