Cobalt(II)-Catalyzed [4 + 2] Annulation of Indolecarboxamides with Alkenes for Regioselective Synthesis of γ-Carbolinones.

We report a cobalt-catalyzed cascade [4 + 2] annulation of the C(sp)-H/N-H bonds in indolecarboxamides with alkenes, facilitated by an 8-aminoquinoline directing group. This reaction represents the first example employing simple olefins as substrates to directly construct the γ-carbolinone motif. Furthermore, it exhibits broad substrate scope and excellent regioselectivity, achieving high yields with various unactivated alkenes, even bulky octadecene. Additionally, the applicability of this transformation was demonstrated through a gram-scale reaction and the synthesis of a drug-active naproxen derivative.