Highly Stereoselective Ruthenium(II)-Catalyzed Direct C2-syn-Alkenylation of Indoles with Alkynes

A carboamide-directed ruthenium-catalyzed C2-hydroindolation of alkynes has been described. This transformation provides a rapid access to free (N-H) C2-syn-alkenylated indole derivatives with the assistance of copper(II) salts, in which the directing group is removed via a one-pot process.