Prediction of enhanced solvent-induced enantioselectivity for a ring opening with a bifurcating reaction path

Barry K Carpenter, Jeremy N Harvey, David R Glowacki

Research output: Contribution to journalArticle (Academic Journal)peer-review

34 Citations (Scopus)
30 Downloads (Pure)

Abstract

Classical molecular dynamics simulations are reported for the deazetisation and ring opening of meso-2,3-difluoro-2,3-dimethyldiazocyclopropane in three solvents: CHCl3, CHFClBr and CH3CH(OH)CF3 (TFIPA). The achiral reactant leads to enantiomeric allene products, and the question addressed in the study is whether either of the chiral, enantiomerically pure solvents can induce significant enantiomeric excess in the products. The direct dynamics calculations use an empirical valence bond potential for the solute, with empirical parameters optimised against M06-2X/cc-pVTZ density functional results. The results reveal that the exothermic N2 loss and ring opening promote transient strong solvent-solute interactions within the first ∼100 fs of the reaction. Because of the bifurcating reaction path, these interactions occur at time when the "decision" about which enantiomer of the product to form has yet to be made (at least for many of the trajectories). Hence, it is possible in principle that the solvent could exert a larger-than-normal influence on the course of the reaction. In fact, the results reveal no such effect for CHFClBr but do predict that TFIPA should induce 15.2 ± 2.1% enantiomeric excess. This is roughly an order of magnitude larger than solvent-induced enantiomeric excesses found experimentally in reactions where the conversion of reactant(s) to enantiomeric products occur over separate transition states.

Original languageEnglish
Pages (from-to)8372-8381
Number of pages10
JournalPhysical Chemistry Chemical Physics
Volume17
Issue number13
DOIs
Publication statusPublished - 7 Apr 2015

Fingerprint Dive into the research topics of 'Prediction of enhanced solvent-induced enantioselectivity for a ring opening with a bifurcating reaction path'. Together they form a unique fingerprint.

Cite this