Interplay between Energy and Entropy Mediates Ambimodal Selectivity of Cycloadditions.

ABSTRACT: One ambimodal transition state can lead to the formation of multiple products. However, it remains fundamentally unknown how the energy and entropy along the post-TS pathways mediate ambimodal selectivity. Here, we investigated the energy and entropy profiles along the post-TS pathways in four [4 + 2]/[6 + 4] cycloadditions. We observe that the pathway leading to the minor product involves a more pronounced entropic trap. These entropic traps, resulting from the conformational change in the dynamic course of ring closure, act as a reservoir of longer-lived dynamic intermediates that roam on the potential energy surface and have a higher likelihood of redistributing to form the other product. The SpnF-catalyzed Diels-Alder reaction produces [4 + 2] and [6 + 4] adducts with nearly equal prod

SUBMITTER: Shin W 

PROVIDER: S-EPMC11673114 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature