Tuning the Trapping of Epoxides by Endo-Functionalized Molecular Tubes in an Aqueous Medium: A Computational Study

In biological and pharmaceutical industries, the production of pure enantiomeric compounds is incredibly essential. In chemistry and biology, chiral epoxides are essential intermediates. It is, therefore, of interest to have a simple procedure to detect and separate epoxide enantiomers. In recent times, several varieties of chiral stationary phases (CSPs) based on supramolecular receptors, such as crown ether, cyclodextrin, and calixarene among others, are available for the separation of chiral molecules. Inspired by this, we have used two already synthesized supramolecular receptor molecules (host-1a and host-1b) (known as endo-functionalized molecular tubes), which may be used to separate the epoxide enantiomer. We present an elaborate description of the structure and the energetics of the chiral separation of epoxide enantiomers. Complexes of epoxide enantiomers having a larger hydrophobic surface area with host-1a and host-1b show significant difference in binding energy and potential of mean force values. This indicates that these water-soluble host molecules may be used as CSPs in chiral chromatography for epoxide chiral enantiomer separation. Host–guest hydrophobic and hydrogen-bonding interactions are the main stabilizing factors for these stable host–guest complexes. We hope that this work may be an excellent pole star for several enantiomeric separations.