New fluorination of organic compounds using thermodynamically unstable nickel fluorides

Abstract

Replacement of hydrogen by fluorine in a variety of organic compounds is accomplished with high efficiency in liquid hydrogen fluoride (aHF), at or below 20 "C, using the thermodynamically unstable fluorides RNiF3 and NiF4, the latter prepared in situ from K2NiF6 with BF3.Fluorocarbon compounds can often be derived from hydrocarbon precursors by well controlled interaction of the latter with elemental fluorine, as pioneered by Margrave and Lagow,' and Lagow and his co-workers.2 Although the convenient reagent cobalt trifluoride, CoF3, is less potent than elemental fluorine, it has long been employed in the synthesis of highly fluorinated organic compounds.' Nevertheless, high temperatures are necessary for the process, depending on the substrate, and this has often resulted in unwanted carboncarbon bond cleavage. Fluorination via the Simons electro-

Free radical and isomerisation processes during the electrochemical fluorination of n-butyryl chloride, i-butyryl chloride and pivaloyl chloride in anhydrous hydrogen fluoride

“…Systematic analysis of a variety of small and large reactants using mainly NMR data of partially as well as perfluorinated samples were found to be in agreement with free radical pathway [2][3][4][5][6][7]. There is also reasonable consensus towards this pathway in recent times [8][9][10][11][12][13][14][15][16].…”

“…The complete NMR data covering 22 compounds obtained from the product mixture during ECPF of IBC are listed in Table 2. These compounds are further classified under the four following categories: (a) reactant IBC and its partially and perfluorinated products without cleavage (1-6); (b) products based on partially and perfluorinated rearranged product, namely NBC (8-11); (c) products based on cleavage of IBC or NBC (12)(13)(14)(15)(16)(17)(18)(19)(20); (d) products from intermolecular methyl transfer (21)(22).…”

“…Five such compounds (12)(13)(14)(15)(16) were identified in the product mixture. Methyl cleavage would normally accompany fluorine substitution at the cleavage position.…”

Low temperature preparation and uses of potent oxidizers

“…Indeed Haszeldine and co-workers [3] and Burden and Tatlow, in their review [4], had conjectured on the possible role of a higher fluoride of nickel at the nickel anode in that process. The effectiveness of the metastable binary fluorides and [NiF 6 ] 2À salts in efficiently fluorinating a variety of hydrido organic compounds, was established in a collaboration with the laboratory of Chambers and co-workers [5].…”

Footsteps of a fluorine chemist

“…These results have encouraged us to think of the nickel fluoride as weakly bound fluorine atoms on nickel and we have drawn the analogy with ECF processes [43].…”