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Ring‐closing olefin metathesis reactions (RCM) using Grubbs II or Hoveyda's catalysts have been applied to a series of N‐alkenyl‐N‐benzyl‐α‐fluoroacrylamides. α‐Fluoro‐α,β‐unsaturated γ‐ or δ‐lactams incorporating a fluorinated double bond were obtained in moderate to good yields, depending on the nature of substituents on the benzyl ring. The corresponding seven‐ and eight‐membered lactams were not formed under similar conditions. When the N‐benzyl group was replaced by an N‐tosyl group, the corresponding ϵ‐lactam was also formed in 38 % yield. When N‐(2‐fluoroallyl) derivatives were used instead of fluoroacryloyl derivatives, six‐, seven‐, and eight‐membered N‐heterocycles were obtained in low yields. This method was also used to synthesize fluorinated α,β‐unsaturated analogues of pyrrolizidine and indolizidine alkaloids from prolinol, and also to synthesize N‐benzyl‐3‐fluoroquinolone in three steps from commercially available 2‐vinylaniline in 44 % overall yield. Also 3‐fluorocoumarin and 3‐fluorochromene were prepared from o‐vinylphenol, and 3‐fluoro‐benzoxepine was available from o‐allylphenol.

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Ring-Closing Metathesis of Vinyl Fluorides Towards -Fluorinated ,-Unsaturated Lactams and Lactones. -It is demonstrated, that ring-closing metathesis of azadienes having a fluorine substituent is successfully applied to the synthesis of a variety of mono-and bicyclic N-heterocycles. The method is extended to the synthesis of 6-and 7-membered O-heterocycles as well. -(MARHOLD, M.; STILLIG, C.; FROEHLICH, R.; HAUFE*, G.; Eur. J. Org. Chem. 2014, 26, 5777-5785, http://dx.doi.org/10.1002/ejoc.201402535 ; Org.-Chem. Inst., Westfael. Wilhelms Univ., D-48149 Muenster, Germany; Eng.) -Mais 10-055

Ring closure reactionsRing closure reactions O 0130 Synthesis of Vinyl Fluorides by Ring-Closing Metathesis. -The ring-closing metathesis of alkenyl α-fluoro acrylamides (III) involving a fluorinated double bond is reported for the first time. The acrylate (V) gives a fluorinated coumarin (VI) under similar conditions. -(MARHOLD, M.; BUER, A.; HIEMSTRA, H.; VAN MAARSEVEEN, J. H.; HAUFE*, G.; Tetrahedron Lett. 45 (2004) 1, 57-60; Org.-Chem. Inst., Westfael. Wilhelms Univ., D-48149 Muenster, Germany; Eng.) -Mais 14-042