Chemoselective Hydro(Chloro)pentafluorosulfanylation of Diazo Compounds with Pentafluorosulfanyl Chloride

Pentafluorosulfanyl chloride (SF5Cl) is the most prevalent reagent for the incorporation of SF5 group into organic compounds. However, the preparation of SF5Cl often relies on hazardous reagents and specialized apparatus. Herein, we described a safe and practical synthesis of a bench‐stable and easy‐to‐handle solution of SF5Cl in n‐hexane under gas‐reagent‐free conditions. The synthetic application of SF5Cl was demonstrated through the unprecedented reaction with diazo compounds. The chemoselective hydro‐ and chloropentafluorosulfanylations of α‐diazo carbonyl compounds were developed in the presence of K3PO4 or copper catalyst, respectively. These reactions provide a direct and efficient access to various α‐pentafluorosulfanyl carbonyl compounds of high value for potential applications. A practical synthesis of SF5Cl from sulfur powder, dry KF, and trichloroisocyanuric acid (TCCA) in MeCN is described. The new synthetic utility of SF5Cl is well demonstrated by the chemoselective hydro(chloro)pentafluorosulfanylation of diazo compounds.