Thermal isomerisation of 1-chloro-1-fluoro-2-vinylcyclopropanes: competition between the vinylcyclopropane–cyclopentene rearrangement and cyclopropyl–allyl transformation

Molecular Rearrangements: Part 1. Pericyclic Reactions

“…The competition between ring-opening modes has been attributed to the contrast between the ability of Cl to stabilize an adjacent radical, and the ability of F to destabilize the bond opposite it in a three-membererd ring. 51 The vinylcyclobutane-cyclohexene rearrangement has been studied using DFT and CASSCF methods. The rearrangement has been found to proceed via diradical species on an almost flat potential energy surface.…”

Switchable light vs. acid-induced transformations of complex framework compounds at room temperature

“…1.0]hept-2-ene) in pentane under irradiation (sources with wavelengths of 185-228 nm) including allene (heptatriene-1,2,6, 13% yield). 23 Several additional examples of the transformation of VCPs into CPs [24][25][26][27][28][29][30][31][32][33][34] are present in the literature, leading to various substituted molecules with a cyclopentene moiety (although not all the described reactions can be carried out under standard conditions, or at least with slight heating). 24,25 Importantly, most VCPs rearrangements show low regioselectivity.…”