704-60-9Relevant academic research and scientific papers
Ring-closing metathesis of vinyl fluorides towards α-fluorinated α,β-unsaturated lactams and lactones
Marhold, Michael,Stillig, Christian,Fr?hlich, Roland,Haufe, Günter
supporting information, p. 5777 - 5785 (2014/10/15)
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 ovinylphenol, and 3-fluoro-benzoxepine was available from o-allylphenol.
