Reactions of Fluoroalkenes with an Aluminium(I) Complex - Clare Bakewell (Imperial College London, 2018)
A series of industrially relevant fluoroalkenes react with a monomeric Al(I) complex. These reactions break either strong sp2 or sp3 C–F bonds and result in the formation of a diverse array of organoaluminium compounds. Mechanistic studies show that two mechanisms are likely in operation: Oxidative addition of the C–F bond to Al(I) occurs with retention of alkene stereochemistry, while stepwise formation and decomposition of a metallocyclopropane intermediate occurs with inversion of alkene stereochemistry. As part of this mechanistic analysis, we have isolated the first aluminium metallocyclopropane complex from oxidative addition of an alkene to Al(I). Remarkably this reaction is reversible and reductive elimination of the alkene occurs at higher temperature reforming Al(I). Furthermore, we show that, in selected cases, the organoaluminium products are susceptible toward beta-fluoride elimination yielding a double C–F activation pathway.