Selective C–H bond fluorination enables conformational reporting in a complex natural product

By stumbling upon a method for selectively fluorinating a skeletal C–H bond in the antibiotic ionophore salinomycin, researchers have been able to monitor its conformation with ¹⁹F NMR. ‘It was a serendipitous discovery – we did not predict the fluorination in advance, so our chemistry was driven very empirically,’ says Thomas Lectka from Johns Hopkins University in the US, who led the research. Consequently, the team used ¹⁹F NMR to directly visualise how salinomycin binds with metals to better understand its biological activity.