Diethyl Fluoronitromethylphosphonate: Synthesis and Application in Nucleophilic Fluoroalkyl Additions. Issue 5 (16th December 2013)

• Record Type: Journal Article
• Authors: Opekar, Stanislav; Pohl, Radek; Beran, Pavel; Rulíšek, Lubomír; Beier, Petr
• Is Part Of: Chemistry. Volume 20:Issue 5(2014)
• Page Start: 1453
• Page End: 1458
• Publication Date: 2013-12-16
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201303817
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Diethyl fluoronitromethylphosphonate (<bold>3</bold>), a previously unknown compound, was synthesized by electrophilic fluorination of diethyl nitromethylphosphonate with Selectfluor. Base‐induced decomposition of <bold>3</bold> was studied by NMR spectroscopy, which identified diethyl fluorophosphate and fluoronitromethane as the main decomposition products. CH acidities [p<italic>K</italic>_a values in dimethyl sulfoxide (DMSO)] of <bold>3</bold>, 1‐fluoro‐1‐phenylsulfonylmethanephosphonate (<bold>1</bold>; McCarthy's reagent), tetraethyl fluoromethylenebisphosphonate (<bold>2</bold>), and some nonfluorinated phosphonates were computed, and a good correlation between calculated and experimental p<italic>K</italic>_a values was found. The calculated CH acidities increased in the sequence <bold>2</bold>&lt;<bold>1</bold>&lt;<bold>3</bold>. Diethyl fluoronitromethylphosphonate (<bold>3</bold>) 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 <bold>3</bold> was successful only with iodomethane, however, conjugate additions of <bold>3</bold> to Michael acceptors such as α, β‐unsaturated carbonyl compounds, sulfones, and nitro compounds allowed access to variously modified diethyl 1‐fluoro‐1‐nitrophosphonates.</p> </abstract>