Copper-Catalyzed Regiodivergent Borylation of Fluorinated Alkynes and Palladium-Catalyzed Regiospecific Suzuki-Miyaura Cross-Coupling

Alkenylboranes are key intermediates in modern organic synthesis, and they are usually obtained by the borylation of alkynes. We report herein highly regio- and stereoselective syntheses of alpha,Z- and beta,Z-trifluoromethylated alkenylboranes by copper-catalyzed borylation reactions. Further functionalizations by palladium-catalyzed Suzuki-Miyaura cross-couplings have been developed and, interestingly, a marked difference in reactivity between the alpha- and beta-borylated isomers has been identified.