Visible Light-Induced Sulfonamidation of [1.1.1]Propellane Promoted by Energy Transfer Catalysis.

Sulfonamides represent an important structural motif present in numerous drugs, however, the scarcity of synthetic methods for bicyclo[1.1.1]pentanesulfonamides has limited the applicability of this compound class. Herein, we report an energy transfer (EnT) promoted photocatalytic strategy for the synthesis of bicyclo[1.1.1]pentanesulfonamides via sulfonamidation of [1.1.1]propellane. This approach utilizes N-nitrososulfonamides as precursors, facilitating the generation of sulfonamide radicals through homolytic cleavage under EnT promotion. These radicals were then found to engage in an addition reaction with [1.1.1]propellane, generating bicyclo[1.1.1]pentane (BCP) radicals that undergo subsequent C─H, C─X, C─S, or C─C coupling reactions to afford a variety of C3-substituted bicyclo[1.1.1]pentanesulfonamides. This strategy featured mild conditions, operational simplicity, with high atomic utilization, and therefore not only offers an efficient synthesis of a range of C3-versatile-substituted BCP sulfonamides, but also significantly broadens the potential applicability of BCP-sulfonamides in drug discovery.