Ionic liquids have been proposed to induce a mechanistic change in the reaction pathway for the fundamentally important base-induced β-elimination class compared to conventional solvents. The role of the reaction medium in the elimination of 1,1,1-tribromo-2,2-bis(3,4-dimethoxyphenyl)ethane via two bases, piperidine and pyrrolidine, has been computationally investigated using methanol and the ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate and hexafluorophosphate [BMIM][BF(4)] and [BMIM][PF(6)], respectively. QM/MM Monte Carlo simulations utilizing free-energy perturbation theory found the ionic liquids did produce a reaction pathway change from an E1cB-like mechanism in methanol to a pure E2 route that is consistent with experimental observations. The origin of the ionic liquid effect has been found as: (1) a combination of favorable electrostatic interactions, for example, bromine-imidazolium ion, and (2) π-π interactions that enhance the coplanarity between aromatic rings maximizing the electronic effects exerted on the reaction route. Solute-solvent interaction energies have been analyzed and show that liquid clathrate solvation of the transition state is primarily responsible for the observed mechanistic changes. This work provides the first theoretical evidence of an ionic liquid dependent mechanism and elucidates the interplay between sterics and electrostatics crucial to understanding the effect of these unique solvents upon chemical reactions.
Pharmacology, Toxicology and Pharmaceutical Science
1
4%
Biochemistry, Genetics and Molecular Biology
1
4%
Physics and Astronomy
1
4%
Other
1
4%
Unknown
8
30%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 31 December 2012.
All research outputs
#20,195,877
of 22,713,403 outputs
Outputs from Journal of the American Chemical Society
#59,991
of 61,827 outputs
Outputs of similar age
#250,037
of 282,352 outputs
Outputs of similar age from Journal of the American Chemical Society
#494
of 546 outputs
Altmetric has tracked 22,713,403 research outputs across all sources so far. This one is in the 1st percentile – i.e., 1% of other outputs scored the same or lower than it.
So far Altmetric has tracked 61,827 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 6.8. This one is in the 1st percentile – i.e., 1% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 282,352 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 1st percentile – i.e., 1% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 546 others from the same source and published within six weeks on either side of this one. This one is in the 1st percentile – i.e., 1% of its contemporaries scored the same or lower than it.
