Desmethyl SuFEx-IT: SO₂F₂-Free Synthesis and Evaluation as a Fluorosulfurylating Agent

Access to SuFExable compounds was remarkably simplified by introduction of the solid FO₂S-donor SuFEx-IT. However, the published process for preparation of this reagent relies on the use of sulfuryl fluoride (SO₂F₂), which is difficult to obtain and highly toxic. Herein, we disclose a simple protocol for SO₂F₂-free, hectogram-scale preparation of the analogous desmethyl SuFEx-IT from inexpensive starting materials. The reagent was prepared in a high (85%) total yield and without chromatographic purification steps. In addition, we demonstrate the utility of desmethyl SuFEx-IT by successful preparation of a series of fluorosulfates and sulfamoyl fluorides in high to excellent yields. As such, our work recognizes desmethyl SuFEx-IT as a valuable alternative to common FO₂S-donors and enables cost-efficient access to substrates for SuFEx click chemistry.