Synthesis of gem-Difluorinated 1,4-Dienes via Nickel-Catalyzed Three-Component Coupling of (Trifluoromethyl)alkenes, Alkynes, and Organoboronic Acids.

Herein, a nickel-catalyzed defluorinative three-component coupling of trifluoromethyl alkenes, internal alkynes, and organoboronic acids is presented. The protocol provides a highly efficient and selective route for the synthesis of structurally diverse gem-difluorinated 1,4-dienes under mild conditions. Mechanistic studies suggest that C-F bond activation proceeds probably through the oxidative cyclization of trifluoromethyl alkenes with Ni(0) species, sequential addition to alkynes, and β-fluorine elimination.