Dialkylamino fluoro

Bromo- and iodoarenes are the oldest and most typical substrates for permutational halogen/metal interconversions. Butyllithium is routinely used for this purpose (Table 16). Hetero-substituents such as dialkylamino or bis(trialkylsilyl)amino, cyano or nitro (Table 17), alkoxy and 2-tetrahydropyranyloxy (Table 18), lithiooxy or lithiooxycarbonyl (Table 19) and fluoro or trifluoromethyl (Table 20) and chloro, bromo or iodo (Table 21) are well tolerated. 

Carboxylic and sulfonic acids e. g. 1 and 3, are smoothly converted under mild conditions to their corresponding fluorides, e.g. 2 and 4 respectively by treatment with (dialkylamino)tri-fluoro-x4-sulfanes. 

The substituents fluoro. chloro, bromo, cyano, nitro, alkoxycarbonyl, A.yV-dialkylaminocar-bonyl and dialkylphosphonyl do not interfere with the molybdenum(Vl) fluoride reactions, but hydroxy, alkoxy, amino, dialkylamino and alkene groups do.9,10... 

Trifluoroprop-l-enyl p-tolucnesulfonate (49) reacts smoothly with various primary or secondary amines in the presence of triethylamine and a catalytic amount of fluoride ion, to afford the corresponding (Z)-a-fluoro-j8-(alkylamino- or dialkylamino)acrylaldehydes 50 in good to excellent yields. ... 

Fluorides are more reactive than the other hahdes, (cf. 3.3.2) for example 2-fluoropyridine can be converted into 2-dialkylamino-pyridines using hthium amides at room temperature. This could be compared with the 130 °C required to displace a-bromine using the potassium salt of pyrazole. Displacement of nitro can be made the means for the synthesis of a- and y-fluoro-pyridines. Of the five fluorines in pentafluoropyridine, the y-fluorine is displaced most rapidly. ... 

Fluorination of 4-thiofuranose hydroxyl-containing derivatives by dialkylamino sulfur trifluoride was successfully applied for the synthesis of 2-fluoro-4-thiosugars 127,128." "" The reactions proceed with complete retention of C-F carbon atom configuration. 

As indicated in Table 6.1 some 2/f-aziiines are isolated from one-pot reactions in which the vinyl azide precursors are produced in situ. For example, 3-dialkylamino-2//-azirines 4 have been prepared from tertiary amides 3 the vinyl azide intermediates are generated by successive chlorination and reaction with sodium azide (Scheme 6.2). The conversion of these vinyl azides into azirines takes place at room temperature and it is clear that the nature of the substituents on the double bond of vinyl azides influences their temperature of decomposition. Fluoro substituted vinyl azides also decompose at room temperature. ... 

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