Benzylic C-H Radical Sulfation by Persulfates.

Sulfation is a highly valuable pathological and physiological process, yet it is often underappreciated considering the rather difficult accessibility of organosulfates. O-sulfonation (O-SO), a conventional and still common way to make organosulfates, restricts its applicability to hydroxyl compounds and therein lies a major challenge of library construction. Here, we describe a benzylic C-H radical sulfation with persulfates via C-O bond formation. This strategy leverages modular control over the reactivity of persulfates and the stability of sulfate radicals by coutercations. K/NH stabilized sulfate radicals act as the oxidant to generate carbon-centered radicals from substrates, and activation of persulfates by n-NBu provides O-O resource pool to facilitate C-OSO bond formation via a bimolecular homolytic substitution (S2) process.