Theoretical study of the sigmatropic rearrangement of cycloprop-2-en-1-ol and its fluorine derivatives: Pericyclic or pseudopericyclic character from NICS and LLPE

Abstract

Sigmatropic rearrangement reaction of cycloprop-2-en-1-ol and its fluorine derivatives has been studied theoretically in gas phase and its energy barrier has been calculated. Nucleus-independent chemical shift shows sigmatropic rearrangement of cycloprop-2-en-1-ol and is pericyclic in nature whereas fluorine derivatives shows pseudopericyclic and pericyclic nature. Substitution of fluorine atom at ring is found to increase the energy barrier for the –OH migration, while substitution at the oxygen atom reduces the barrier. To know the involvement of the lone pair of electrons during the reaction, lone pair electron present on the oxygen atom is locked by hydrogen bonding. CR-CCSD(T)/6-311+G** levels are used to study the reactions more accurately.