Controlled Synthesis of Enantioselective 1‑Aminoindenes via Cobalt-Catalyzed [3 + 2] Annulation Reaction

A cobalt-catalyzed synthesis of 1-aminoindenes
via enantioselective
[3 + 2] annulation is described. In this reaction, the desired products
can be selectively prepared in either (R)- or (S)-form by the ligand-controlled synthesis, which is initiated
by the cleavage of C–B, C–Br, or C–O bonds under
very mild reaction conditions. In addition, this enantioselective
cobalt catalysis provides high regioselectivity for both internal
and terminal alkynes, and affords products generally in high yields
and ee values.