(E)- or (Z)-α-Fluoroenones via Kinetically Controlled Negishi Coupling

Significance

The authors describe the synthesis of either (E)- or (Z)-α-fluoroenones through kinetic control. Formation of α-alkoxyvinyl zinc chlorides and subsequent coupling with bromofluoro olefins affords isomerically enriched bromofluoro olefins. The E isomer reacts under Negishi coupling conditions providing high purity of the (Z)-bromofluoro­alkene. The product arising from Negishi coupling with the E isomer can be hydrolyzed to the ketone. The (Z)-bromofluoroalkene can then be coupled to give the opposite isomer generated from the kinetic reaction, enabling access to both isomers.