Andrew J. Poss

1-Fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) as a new, effective reagent for selective fluorofunctionalisation of alkenes under mild reaction conditions

Abstract 1-Fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) ( Accufluor ™ NFTh) is confirmed as a highly effective reagent for introducing a fluorine atom into organic molecules across a phenyl-substituted carbon-carbon double bond. Quantitative and Markovnikov-type regioselective formation of vicinal fluoro-hydroxy, fluoro-methoxy or fluoro-acetoxy adducts was achieved when phenyl-substituted alkenes were treated with a MeCN solution of NFTh In the presence of water, methanol or acetic acid. The stereochemical course of fluoro-methoxylation reactions in the case of cyclic phenyl-substituted alkenes depends strongly on the structure of the alkene.

1-fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate): An electrophilic fluorinating agent

Abstract 1-Fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate), NFTh, is a electrophilic fluorinating that can be used to fluorinate aromatic rings, olefins, dienol acetates and enol ethers. When NFTh is reacted with an active methylene compound in the presence of ZnCl 2 , the corresponding monoor di-fluoro derivative can be isolated.

Estimation of hydrocarbon solubilities in hydrofluorocarbons

Abstract A new solubility parameter, SP, for hydrofluorocarbons (HFCs) has been developed (SP=1.175 ln(np)+ 0.025H-0.063F-0.028α-0.018β where np depends on the molar volume and the molar refractivity; H and F are the number of hydrogens and fluorines, respectively, in the molecule; and α and β are the respective numbers of H-C-F and H-C-C-F connections). Values of SP have been used to predict if an HFC would be a good solvent for various hydrocarbons at 25 °C. Within an isomeric HFC family, the individual HFCs having the greatest solvency for hydrocarbons were those having the maximum separation of fluorines from hydrogens. Hildebrand solubility parameters, δ, are compared with the semi-empirical SP values. Syntheses for 10 new compounds are given: 3,3,4,4,5,5,6,6,7,7-decafluorononane, 1,1,1,2-tetrafluoro-2-(trifluoromethyl)-3-methylbutane, 1,1,1,2,2-pentafluoro-3-methylbutane, 1,1,1,2,2,3,3,4,4-nonafluoro-5-methylhexane, 1,1,1,2,2,3,3,4,4-nonafluoroheptane, 1,1,1,2-tetrafluoro-2-(trifluoromethyl)butane, 1,1,1-trifluoro-3-(trifluoromethyl)butane, 1,1,1,2,2,3,3,5-octafluorohexane, 1,1,1,2,2-pentahydroperfluorooctane and 1,1,1,2,2-pentahydroperfluorodecane.

Reductive dehalogenation of polyhalofluorocarbons with tributyltin hydride

Abstract The reduction of polyhalofluorocarbons, including ClCF2CFClCF2Cl, (ClCF2CFCl)2, ICH2(CF2)3CH2I and vicinal dichloro-perfluorocycloalkanes, with tributyltin hydride gave the corresponding hydrofluorocarbons in good to excellent yield. The results are compared with similar reductions with other reducing agents, and to tin hydride reductions of non-fluorinated analogs.

γ-Fluorination of unsaturated ketones with N-fluorobenzenesulfonimide

Abstract The reaction of potassium dienoxy borates with N-fluorobenzenesulfonimide affords γ-fluoro enones in good yields. The potassium dienoxy borates are prepared by treating potassium enolates derived from unsaturated ketones with 2-phenyl-1,3,2-benzodiosaborole.

N-fluoropyridinium pyridine heptafluorodiborate: a useful fluorinating agent

Abstract N-Fluoropyridinium pyridine heptafluorodiborate (NFPy) has recently been developed as a safe and inexpensive source of electrophilic fluorine. The preparation and reactivity of NFPy with organic compounds will be described. This novel reagent reacts under mild conditions to selectively transfer fluorine to the reactive sites of enol derivatives.