Regio- and Stereospecific Copper-Catalyzed Substitution Reaction of Propargylic Ammonium Salts with Aryl Grignard Reagents.

We have developed a copper-catalyzed substitution reaction of propargylic ammonium salts with aryl Grignard reagents. The reaction is stereospecific and α-regioselective and proceeds with exceptional functional group tolerance. Conveniently, a stable, inexpensive, and commercially available copper salt is used and no added ligand is required.