Cobalt‐Catalyzed Hydroalkynylation of Vinylaziridines

Transition metal‐catalyzed hydroalkynylation reactions are efficient transformations allowing the straightforward formation of functionalized alkynes. Therein, we disclose the cobalt‐catalyzed hydroalkynylation of vinylaziridines giving rise to both linear and branched enynes. The optimization of the reaction conditions allowed to determine the key parameters of the cobalt‐based catalytic system. The scope investigation showed that the cobalt‐catalyzed hydroalkynylation is mainly limited to phenylacetylene derivatives. In most cases branched and linear enynes were isolated in equimolar proportions (20 examples). Additional experiments allowed us to propose a plausible mechanism. Finally, the hydroalkynylation products were further subjected to an iodocyclization affording a 2,3‐dihydropyrrole derivative and a platinum‐catalyzed cycloisomerization.