Construction of Pyrrolo[1,2‑a]indoles via Cobalt(III)-Catalyzed Enaminylation of 1‑(Pyrimidin-2-yl)‑1H‑indoles with Ketenimines and Subsequent Base-Promoted Cyclization

A cobalt­(III)-catalyzed cross-coupling reaction of 1-(pyrimidin-2-yl)-1H-indoles with ketenimines is reported. The reaction provided 2-enaminylated indole derivatives in moderate to excellent yields with a broad substrate scope. The prepared 2-enaminylated indoles could be conveniently converted into pyrrolo­[1,2-a]­indoles, which are an important class of compounds in medicinal chemistry.