First Stereospecific Synthesis of (E)‐ or (Z)‐α‐Fluoroenones via a Kinetically Controlled Negishi Coupling Reaction.

Abstract

2006 Halogen compounds Q 0090First Stereospecific Synthesis of (E)-or (Z)-α-Fluoroenones via a Kinetically Controlled Negishi Coupling Reaction. -Treatment of a mixture of (E)-and (Z)-bromofluoroalkenes with vinylzinc chlorides at 10°C results in selective formation of (Z)-α-fluoroenones. At this temperature only the (E)-isomers are converted. The (Z)-isomers do not react and can easily be separated from the products. At 55-70°C the (Z)-isomers also undergo Negishi coupling to give (E)-α-fluoroenones which sometimes undergo isomerization. -(DUTHEUIL, G.; PATUREL, C.; LEI, X.; COUVE-BONNAIRE, S.; PANNECOUCKE*, X.; J. Org. Chem. 71 (2006) 11, 4316-4319; Inst. Rech. Chim. Org. Fine Heterocycl., CNRS, Inst. Natl. Sci. Appl. Rouen, F-76131 Mont-Saint-Aignan, Fr.; Eng.) -Jannicke 43-070

Palladium-Mediated Organofluorine Chemistry

“…142 The synthesis of fluorinated alkenes by reaction of a fluorovinyl halide and a non-fluorinated zinc organometallic compound has also been reported. 143,144 Fluorovinyl …”

2-Fluoroenones via an Umpolung Morita–Baylis–Hillman Reaction of Enones

“…6a,9 Addition of in situgenerated phenylselenyl fluoride (from PhSe-Br and AgF) to α-diazoketones and α-diazoesters was also reported. 17 1-Bromovinyl fluorides 18 or 1-chlorovinyl fluorides 11 may be coupled with alkoxyvinylzinc reagents using palladium catalysis. Again, these reactants are prepared in multistep sequences.…”