On the inherent instability of alpha-amino alpha'-fluoro ketones. Evidence for their transformation to reactive oxyvinyliminium ion intermediates.
[figure: see text] alpha-Amino alpha'-fluoro ketones are shown to be inherently unstable intermediates. Evidence is presented that they undergo enolization toward the amino group followed by expulsion of fluoride ion, forming a proposed oxyvinyliminium ion (amino-substituted oxyallyl cation). In protic, nucleophilic media the proposed intermediate is trapped by solvent. In the presence of a reactive diene, [4 + 3] cycloadducts have been isolated. Prior observations concerning fluorinated amino ketones are discussed in light of these findings.
Myers
A G
AG
Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA. myers@chemistry.harvard.edu
Barbay
J K
JK
D002412:Cations; D007659:Ketones / Q000737:chemistry* / Q000494:pharmacology; D011480:Protease Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D014753:Vinyl Compounds / Q000737:chemistry*
D002412:Cations; D007659:Ketones; D011480:Protease Inhibitors; D014753:Vinyl Compounds