Fluonnation hydrogen replacement

Vanadium pentafluoride replaces benzylic hydrogen by fluonne but also adds fluonne to the aromatic system, giving fluonnated cyclohexadienes and cyclohexenes [5] (equation 5)... 

Fluonnation of aliphatic hydrocarbons with cobalt trifluoride gives complex mixtures Isobutane (2-methylpropane) fluonnated at 140-200 °C affords a mixture of 30 products of different degrees of fluorination and of isobutane as well as butane skeletons. The tertiary hydrogen is replaced preferentially Products containing 5-10 atoms of fluorine including a small amount of perfluoroisobutane were isolated [70]. 

Similar preference in replacement by fluorine of tertiary versus secondary and secondary versus primary hydrogens is observed in the fluonnation of alkanes with chlorine tnfluonde in 1,2-difluorotetrachIoroethane at room temperature (Table 3). Skeletal rearrangements accompany the fluorination [77]... 

Acetyl hypofhiorite is very effective in the fluorination of the aryl-metal (Hg, Ge, or Si) bond, but yields are frequently low. With aryl silicon compounds some competition exists for replacement of an aromatic hydrogen [51, 52, 53, 54] (equations 25-27). Fluoroxytrifluoromethane fluonnates p-methoxypheny 1 mercuric acetate to give p-fluoroanisole in 86% yield [52]... 

One of the most useful ways of introducing fluorine into organic compounds is the replacement of the hydroxyl group in alcohols hydroxy compounds, and carboxylic acuis Methyl alcohol reacts with anhydrous hydrogen fluoride at 100 500 °C in the presence of aluminum fluoride [60, 61], zinc fluoride [62] chromium fluonde [63], or a mixture of aluminum and chromium fluorides [64] to give a 20-78% yield of fluoromethane Attempted fluonnations of higher alcohols by this method failed [60]... 

Replacement of hydrogen with halogen can be carried out in the alpha position of fluonnated ethers, amines, aldehydes, or nitriles In 2,2,3,4,4,4 hexafluoro-butyl methyl ether, chlorination occurs predominantly at the methyl, however, bromination occurs mostly at the internal position of the fluorobutyl group 13[Pg.372]

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