Co(II)-Catalyzed C–H/N–H Annulation of Cyclic Alkenes with Indole-2-carboxamides at Room Temperature: One-Step Access to β‑Carboline-1-one Derivatives

We report herein a cobalt-catalyzed 8-aminoquinoline-directed highly regio- and stereoselective C–H/N–H activation annulation of indole-2-carboxamides with 1,2-dihydronaphthalene for the synthesis of β-carboline-1-one derivatives at room temperature. A cheaper and commercially available cobalt catalyst has been used for this transformation. The protocol tolerates a wide range of functionalities, affording β-carboline-1-one derivatives in good yields. An initial mechanistic study revealed a reversible cyclometalation to be operative.