Dearomative Vinylation of Indoles via Multicomponent Photoredox Thiol-Yne-Heteroarene Coupling Reaction.

Dearomative addition reactions of indoles represent a prominent strategy for the synthesis of practically valuable indolines. However, implementing this approach typically requires prefunctionalization of the indole precursor with specific groups (e.g., alkynes, alkenes, or ketones) to facilitate the subsequent cyclization-dearomatization step. In this work, we report a three-component, thiol-yne-mediated dearomative vinylation of indoles that circumvents the need for preinstalling reactive fragments into the indole scaffold. The developed photoredox-catalyzed thiol-yne-heteroarene reaction employs Boc-protected indole-3-carboxylates as effective terminating agents for the radical cascade.