Base-mediated reactions of diethyl malonates derivatives with perfluorinated olefins: Novel synthetic routes to multifunctional ionomer precursors

Abstract

A novel synthetic method for the preparation of per- and polyfluorinated unsaturated 2-substituted malonates is presented involving the deprotonation of the starting diethyl malonate by a strong base, followed by in situ addition of the C-nucleophile to the terminal double bond of the perfluorinated olefin. Subsequent elimination of the corresponding leaving groups and restoring of the double bond leads to the target bifunctional perfluorinated olefins. In the case of unsubstituted diethyl malonate, the elimination is accompanied by a prototropic rearrangement with a double bond migration and the addition of a second equivalent of the C-nucleophile forming the tetrafunctional internal olefins. The reaction conditions, factors affecting the reactivity and regioselectivity of the process, the choice of reagent as well as the course of competitive reactions are also discussed.