Modular Access to -SF Azetidines.

A general and modular strategy has been developed for the synthesis of -SF azetidines, a new class of scaffolds with potential utility in medicinal chemistry. This transformation leverages bench-stable and scalable SF-transfer reagents to generate the SF radical, which engages azabicyclo[1.1.0]butanes bearing ketone, ester, alkyl, or aryl substituents in strain-release difunctionalization reactions. The method proceeds under mild reaction conditions, features broad functional group tolerance, and offers operational simplicity. The resulting -SF azetidines demonstrate high aqueous stability and increased lipophilicity, positioning them as a novel class of potential bioisosteres in medicinal chemistry.