Acid Promoted Tetrafunctionalization of Terminal Alkynes: Geminal Diazidation and Dibromination

The synthesis of complex alkanes by the tetrafunctionalization of alkynes is limited and challenging. Herein, an unprecedented efficient geminal diazidation and dibromination of terminal alkynes is developed, which provides novel access to structurally diverse organic azides. The approach has exclusive chemo- and regioselectivity and features mild reaction conditions, good tolerance of various functional groups, and more crucially, no metal involved in the reaction, thereby benefiting the late-stage decoration of medicinal molecules. A mechanistic study showed that the current geminal diazidation and dibromination proceeds via a radical pathway.