A unified flow strategy for the preparation and use of trifluoromethyl-heteroatom anions

The trifluoromethyl group (CF₃) is a key functionality in pharmaceutical and agrochemical development, greatly enhancing the efficacy and properties of resulting compounds. However, attaching the CF₃ group to heteroatoms such as sulfur, oxygen, and nitrogen poses challenges because of the lack of general synthetic methods and reliance on bespoke reagents. Here, we present a modular flow platform that streamlines the synthesis of heteroatom-CF₃ motifs. Our method uses readily available organic precursors in combination with cesium fluoride as the primary fluorine source, facilitating the rapid generation of <i>N</i>-trifluoromethyl(R) [NCF₃(R)], SCF₃ (trifluoromethylthio), and OCF₃ (trifluoromethoxy) anions on demand without reliance on perfluoroalkyl precursor reagents. This strategy offers a more environmentally friendly synthesis of trifluoromethyl(heteroatom)-containing molecules, with the potential for scalability in manufacturing processes facilitated by flow technology.