Copper-catalyzed reductive deimination of sulfoximines to sulfoxides

A novel copper-catalyzed reductive deimination strategy for synthesizing sulfoxides from sulfoximines is reported. This method employs donor-acceptor diazoesters as safe carbene precursors, enabling the reaction to proceed efficiently under ambient air at room temperature. The protocol eliminates the use of toxic organomercury reagents and harsh conditions, offering a broad substrate scope with functional group compatibility (e.g., allyl, hydroxyl, and pyridyl). Sulfoxides were obtained in good to excellent yields (up to 91%) across diverse substrates, including diaryl, fused-ring, and alkyl derivatives. Gram-scale synthesis and mechanistic studies further demonstrated the practicality and reaction pathway. This approach addresses critical limitations of traditional methods, providing an environmentally benign and operationally simple route to synthesize biologically relevant sulfoxides.