Sulfonium Salts Enable the Direct Sulfenylation of Activated C(sp3)−H Bonds

Abstract Herein, the direct α‐sulfenylation of a series of β‐dicarbonyl, β‐ketophosphonate, and β‐ketonitrile compounds, mediated by sulfonium salts has been described. Traditionally, sulfonium salts which are synthesized by activation of dialkylsulfoxides serve as oxidizing agents or precursors of sulfur ylide. In this transformation, sulfonium salts as readily prepared and operationally simple sulfenylation reagents firstly achieved alkylsulfenylation of various activated C( sp 3 )−H bonds with the formation of tetra‐substituted carbon center.