Reactions of Fluoroalkenes with an Aluminium(I) Complex.

A series of industrially relevant fluoroalkenes react with a monomeric Al complex. These reactions break strong sp and sp 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: 1) direct oxidative addition of the C-F bond to Al occurs with retention of alkene stereochemistry, and 2) 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 . Remarkably this reaction is reversible and reductive elimination of the alkene occurs at higher temperature reforming Al . Furthermore, in selected cases the organoaluminium products are susceptible toward β-fluoride elimination to yield a double C-F activation pathway.