A metal-free strategy to construct fluoroalkyl–olefin linkages using fluoroalkanes

Abstract

We present a metal-free strategy to access fluoroalkyl–olefin linkages from fluoroalkane precursors and vinyl-pinacol boronic ester (BPin) reagents. This reaction sequence is templated by the boron reagent, which induces C–C bond formation upon oxidation. We developed this strategy into a one-pot synthetic protocol using RCF₂H precursors directly with vinyl-BPin reagents in the presence of a Brønsted base, which tolerated oxygen- and nitrogen-containing heterocycles, and aryl halogens. We also found that HCF₃ (HCF-23; a byproduct of the Teflon industry) and CH₂F₂ (HCF-32; a low-cost refrigerant) are amenable to this protocol, representing distinct strategies to generate RCF₂H and RCF₃ molecules. Finally, we demonstrate that the vinyldifluoromethylene products can be readily derivatized, representing an avenue for late-stage modification after installing the fluoroalkyl unit.