Electrochemical Oxo-Fluorosulfonylation of Alkynes under Air: Facile Access to β-Keto Sulfonyl Fluorides

Radical fluorosulfonylation is emerging as an appealing approach for the synthesis of sulfonyl fluorides, which have widespread applications in many fields, in particular in the context of chemical biology and drug development. Here, we report the first investigation of FSO2 radical generation under electrochemical conditions, and the establishment of a new and facile approach for the synthesis of beta-keto sulfonyl fluorides via oxo-fluorosulfonylation of alkynes with sulfuryl chlorofluoride as the radical precursor and air as the oxidant. This electrochemical protocol is amenable to access two different products (beta-keto sulfonyl fluorides or alpha-chloro-beta-keto sulfonyl fluorides) with the same reactants. The beta-keto sulfonyl fluoride products can be utilized as useful building blocks in the synthesis of various derivatives and heterocycles, including the first synthesis of an oxathiazole dioxide compound. Furthermore, some beta-keto sulfonyl fluorides and derivatives exhibited notably potent activities against Bursaphelenchus xylophilus and Colletotrichum gloeosporioides.