Outer-Sphere Electrophilic Fluorination of Organometallic Complexes

Abstract

Organofluorine chemistry plays a key role in materials science, pharmaceuticals, agrochemicals, and medical imaging. However, the formation of new carbon–fluorine bonds with controlled regiochemistry and functional group tolerance is synthetically challenging. The use of metal complexes to promote fluorination reactions is of great current interest, but even state-of-the-art approaches are limited in their substrate scope, often require activated substrates, or do not allow access to desirable functionality, such as alkenyl C­(sp²)–F or chiral C­(sp³)–F centers. Here, we report the formation of new alkenyl and alkyl C–F bonds in the coordination sphere of ruthenium via an unprecedented outer-sphere electrophilic fluorination mechanism. The organometallic species involved are derived from nonactivated substrates (pyridine and terminal alkynes), and C–F bond formation occurs with full regio- and diastereoselectivity. The fluorinated ligands that are formed are retained at the metal, which allows subsequent metal-mediated reactivity