Transition-Metal-Free Stereospecific Cross-Coupling with Alkenylboronic Acids as Nucleophiles

We herein report a transition-metal-free cross-coupling between secondary alkyl halides/mesylates and aryl/alkenylboronic acid, providing expedited access to a series of nonchiral/chiral coupling products in moderate to good yields. Stereospecific SN2-type coupling is developed for the first time with alkenylboronic acids as pure nucleophiles, offering an attractive alternative to the stereospecific transition-metal-catalyzed C­(sp2)–C­(sp3) cross-coupling.