The First α-Fluoroallenylphosphonate, the Synthesis of
Conjugated Fluoroenynes, and the Stereoselective Synthesis of
Vinylfluorophosphonates Using a New Multifunctional
Fluorine-Containing Building Block
Antonio J. Zapata
Yonghong Gu
Gerald B. Hammond
10.1021/jo991620p.s001
https://acs.figshare.com/articles/journal_contribution/The_First_-Fluoroallenylphosphonate_the_Synthesis_of_Conjugated_Fluoroenynes_and_the_Stereoselective_Synthesis_of_Vinylfluorophosphonates_Using_a_New_Multifunctional_Fluorine-Containing_Building_Block/3720297
Limitations on current methodologies for the introduction of CF<sub>2</sub> and CFH in complex α-fluorophosphonates led to the synthesis of a fluorine-containing building block TIPS-C⋮CCFXP(O)(OEt)<sub>2</sub>,
where X = H or F. This multifunctional fluorine synthon reacts with carbonyl compounds under
WHE conditions to give high yields of fluorinated conjugated enynes and enediyne. When X = F,
trapping of the desilylated anion with an electrophile after TIPS removal provided exclusive access
to γ-substituted derivatives of α-fluorophosphonates. When X = H, TBAF deprotection of the silyl
group yields H<sub>2</sub>CCCFP(O)(OEt)<sub>2</sub> through an allenyl−propargyl resonance stabilized anion. The
allene moiety has been used as template in the stereoselective synthesis of α-fluoro-β,γ-diiodopropenyl phosphonate, via electrophilic iodination, and α-fluoro-γ-amino-α,β-unsaturated
phosphonates, including unsaturated phosphononucleosides, by nucleophilic displacement of an
allylic iodide. Hydroamination of H<sub>2</sub>CCCFP(O)(OEt)<sub>2</sub> using secondary amines produced (Z)-α-fluoroenaminophosphonates, whereas Diels−Alder cycloaddition with cyclopentadiene provides the
corresponding exocyclic vinylfluorophosphonate.
1999-12-17 00:00:00
allenyl
derivative
Conjugated Fluoroenynes
Hydroamination
yield
allene moiety
electrophile
allylic iodide
Stereoselective Synthesis
New
phosphononucleoside
access
template
First
TBAF deprotection
Fluoroallenylphosphonate
resonance
Multifunctional
TIPS removal
exocyclic vinylfluorophosphonate
Vinylfluorophosphonate
introduction
Diel
nucleophilic displacement
enediyne
Limitation
amines
desilylated anion
WHE conditions
stereoselective synthesis
cyclopentadiene
methodology
cycloaddition
multifunctional fluorine synthon
CF 2
carbonyl compounds
electrophilic iodination
CFH