Nickel‐Catalyzed Cyclization of Difluoro‐Substituted 1,6‐Enynes with Organozinc Reagents through the Stereoselective Activation of CF Bonds: Synthesis of Bicyclo[3.2.0]heptene Derivatives

Quite a gem: A nickel-catalyzed cyclization of 1,6-enynes, bearing a gem-difluoro group at the olefinic terminus, with organozinc reagents gives the title compounds (see scheme). One of the fluorine atoms is stereoselectively replaced by the R′ group of R′2Zn, indicating the involvement of the stereoselective activation of a C–F bond.