Gold(I)-Catalyzed Synthesis of 3-Sulfenyl Pyrroles and Indoles by a Regioselective Annulation of Alkynyl Thioethers

The combination of nucleophilic nitrenoids and pacid catalysis has emerged as a powerful tool in heterocycle synthesis. Accessing more varied heterocycle-substitution patterns by maintaining the same reaction pathways across different alkynes remains a challenge. Here we show that Au(I) catalysis of isoxazole-based nitrenoids with alkynyl thioethers provides controlled access to (3 + 2) annulation by a regioselective addition beta to the sulfenyl group. The reaction with isoxazole-containing nitrenoids delivers sulfenylated pyrroles and indoles as single regioisomers bearing useful functional groups and structural variety.

Automated summary

The research demonstrates the controlled access to (3+2) annulation by Au(I) catalysis of isoxazole-based nitrenoids with alkynyl thioethers, resulting in the synthesis of sulfenylated pyrroles and indoles as single regioisomers bearing useful functional groups and structural variety. This offers a new strategy for achieving varied heterocycle-substitution patterns by maintaining the same reaction pathways across different alkynes.