title: Diethyl fluoronitromethylphosphonate: synthesis and application in nucleophilic fluoroalkyl additions.
abstract: Diethyl fluoronitromethylphosphonate (3), a previously unknown compound, was synthesized by electrophilic fluorination of diethyl nitromethylphosphonate with Selectfluor. Base-induced decomposition of 3 was studied by NMR spectroscopy, which identified diethyl fluorophosphate and fluoronitromethane as the main decomposition products. C-H acidities [pK(a) values in dimethyl sulfoxide (DMSO)] of 3, 1-fluoro-1-phenylsulfonylmethanephosphonate (1; McCarthy's reagent), tetraethyl fluoromethylenebisphosphonate (2), and some nonfluorinated phosphonates were computed, and a good correlation between calculated and experimental pK(a) values was found. The calculated C-H acidities increased in the sequence 2<1<3. Diethyl fluoronitromethylphosphonate (3) was applied in the Horner-Wadsworth-Emmons reaction with aldehydes and trifluoromethyl ketones to provide new 1-fluoro-1-nitroalkenes with good to high stereoselectivities. Alkylation of 3 was successful only with iodomethane, however, conjugate additions of 3 to Michael acceptors such as α,β-unsaturated carbonyl compounds, sulfones, and nitro compounds allowed access to variously modified diethyl 1-fluoro-1-nitrophosphonates.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Opekar
authors.forename: Radek
authors.initials: R
authors.lastname: Pohl
authors.forename: Pavel
authors.initials: P
authors.lastname: Beran
authors.forename: Lubomír
authors.initials: L
authors.lastname: Rulíšek
authors.forename: Petr
authors.initials: P
authors.lastname: Beier
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000478:Alkylation; D005461:Fluorine / Q000737:chemistry*; D054879:Halogenation; D007659:Ketones / Q000737:chemistry; D009574:Nitro Compounds / Q000737:chemistry; D063065:Organophosphonates / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism; D013450:Sulfones / Q000737:chemistry
chemical_list: D000447:Aldehydes; D007659:Ketones; D009574:Nitro Compounds; D063065:Organophosphonates; D013450:Sulfones; D005461:Fluorine