Synthesis of Pentafluorosulfanylated Ynamides and Further Functionalizations

L. Popek, G. Lefebvre, V. Debrauwer, D. Roubaud, N. Blanchard, C. Meyer, V. Bizet
Org. Lett. 2024, 48, 10369–10375 ; https://doi.org/10.1021/acs.orglett.4c03972

Herein is described the first synthesis of SF5-ynamides, versatile building blocks featuring the pentafluorosulfanyl motif. This synthesis proceeds through a two-step sequence of radical SF5-addition onto the π-system of a wide range of terminal ynamides and derivatives substituted with various nitrogen fragments followed by a dehydrochlorination reaction. A selection of downstream functionalization reactions, including nucleophilic additions, cycloadditions, and sulfur ylide synthesis, highlights the wide-ranging applications of this novel type of functionalized SF5-building block.