Anti-Markovnikov ring-opening of sulfonium salts with alkynes by visible light/copper catalysis

Internal alkynes are widespread skeletons in bioactive molecules and materials which are also used as important building blocks in chemical synthesis. Herein, we report a novel and efficient copper-catalyzed Sonogashira reaction between sulfonium salts and alkynes through an anti-Markovnikov ring-opening pathway promoted by visible light. The coexistence of the nitrogen and phosphorus ligands in the system is the key to the success of this reaction. This radical type ring-opening reaction affords a new strategy for the synthesis of internal alkynes. Furthermore, this study is also an effective complement to the diverse reaction patterns of sulfonium salts.

Automated summary

This study reports a novel and efficient copper-catalyzed Sonogashira reaction between sulfonium salts and alkynes, promoted by visible light, for the synthesis of internal alkynes. The coexistence of nitrogen and phosphorus ligands in the system is crucial for the success of this reaction.