Direct trideuteromethylselenation with a shelf-stable reagent Se-methyl-d3 selenosulfonate†

The direct incorporation of deuterated functional groups into organic molecules has emerged as a strategically important approach in synthetic chemistry. Among various deuterated moieties, the selenomethyl-d₃ group has attracted significant attention but remains underexplored, primarily due to the limited availability of versatile synthetic precursors. In this work, we have developed an electrophilic trideuteromethylselenating reagent, Se-methyl-d₃ benzenesulfonoselenoate with >99% D-incorporation. This reagent can be conveniently synthesized through a one-step procedure and enables efficient trideuteromethylselenation for diverse nucleophiles or electrophiles, including boronic acids, boronic esters, terminal alkynes, β-ketoesters, oxindoles and diazodium salts under mild reaction conditions. Furthermore, the difunctionalization of unactivated alkenes by simultaneous construction of C–S and C–SeCD₃ bonds is well-documented. The utility of the odourless electrophilic SeCD₃ reagent has been demonstrated through late-stage modification of various bioactive molecules.