Copper-Catalyzed Intermolecular Asymmetric Propargylic Dearomatization of Indoles

The first copper-catalyzed intermolecular dearomatization of indoles by an asymmetric propargylic substitution reaction was developed. This method provides a highly efficient synthesis of versatile furoindoline and pyrroloindoline derivatives containing a quaternary carbon stereogenic center and a terminal alkyne moiety with up to 86% yield and 98% ee.