Alkali metal fluorides synthesis

For a discussion, see Ficser Fiescr Reagents for Organic Syntheses, vol. I Wiley New York. 1967, pp. 606-609. For a review of alkali-metal fluorides in this reaction, sec Yakobson Akhmetova Synthesis 1983, 169-184, pp. 170-173. 

Such reactions occur only at elevated temperatures and, from the scanty evidence available, appear to yield mixtures of products so that their use in synthesis seems unlikely. The role of the alkali metal fluorides has not been explained. 

Among the systems of alkali metal fluorides containing boron oxide, the melts of the system LiF-KF-B203-Ti02 were tested as possible electrolytes in the electro-chemical synthesis of titanium diboride, especially when well-dispersed powders should be... 

CF2 CF-CF8, CF2 CFC1, and CF2-CF CF-CF2 with an alkali-metal fluoride, react with silver trifluoroacetate to give the corresponding per- or poly-fluoroalkyl-silver (see also pp. 353). Other uses of silver trifluoroacetate in synthesis include ... 

The synthesis of alkali metal xanthates from trimethylsilyl dithiocarboxylates and alkali metal fluorides has been deseribed as eonvenient and useful for preparative purposes of metal complexes and organometallic derivatives. 

The hydrothermal method has been employed in recent years to synthesize a variety of solids that include aluminium phosphates (ALPOs) and other microporous transition-metal phosphates and transition-metal polychalcogenides (Davis Lobo, 1992 Haushalter Mundi, 1992 Liao Kanatzidis, 1990, 1992). Unlike zeolites, synthesis of ALPOs requires acidic or mildly basic conditions and no alkali metal cations. A typical synthetic mixture for making ALPO consists of alumina, H3PO4, water and an organic material such as a quaternary ammonium salt or an amine. The hydrothermal reaction occurs around 373-573 K. The use of fluoride ions, instead of hydroxide ions as mineralizer, allows synthesis of novel microporous materials under acidic conditions (Estermann et al, 1991 Ferey et ai, 1994). 

In the synthesis of fluorinated alcohols porous aluminum trifluoride has been found to be an efficient substitute for anhydrous hydrogen fluoride in combination with alkali metal acid fluorides for ring-opening reactions of aliphatic 7-oxabicyclo[4.1.0]heptane fluorohydrins under sonification.47... 

A related 3-elimination occurs when alkali-metal salts of perfluoroalkanecarboxylic acids are pyrolysed [34] (Figure 6.25). The most likely process involves decarboxylation with elimination of fluoride ion from the resultant carbanion. Indeed, the method can be very useful for the synthesis of perfluoroalkenes (Chapter 7), the most important example of which is shown in Figure 6.26 and is used in the production of fluorinated membranes [35]. 

Pyrolysis of alkali-metal salts does not lead to simple decarboxylation but, instead, elimination of fluoride also occurs this is a useful S3mthetic method [36], commercialised in the synthesis of monomer for the manufacture of Nafion [37] (Figure 8.1) see Chapter 7, Section IIB for the preparation of fluoroalkenes. 

Whitney et al. reported C1F3 and BF5 to be promising liquid media for fluorination and the synthesis of complex fluorides based on alkali metal salts [25]. These solvents were prone to auto-ionization according to equations... 

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