Cobalt-Catalyzed C-2 Functionalization of N-methyl- indole-1-carboxamide via regioselective hydroindolation of 1,6-diyne

In this study, we present the novel reactivity of a cobalt (III) catalyst in the context of the functionalization of 1,6-diynes. Our mechanistic investigation reveals the intrinsic formation of a five membered cobaltacycle, which subsequently undergoes migratory insertion with 1,6-diynes. Additionally, radical trapping studies provide compelling evidence supporting the involvement of an ionic pathway in this transformation. Furthermore, the deuterium exchange experiment lends further support to our proposed mechanism. Significantly, this methodology exhibits extensive versatility, accommodating a diverse array of electronically distinct substrates and reactive partners in a highly atom-efficient manner.

Publication History

Received: 02 August 2025

Accepted after revision: 14 September 2025

Accepted Manuscript online:
14 September 2025