SUBSTITUTION AND ADDITION REACTIONS OF NF4BF4 WITH AROMATIC COMPOUNDS

Article abstract of DOI:10.1016/S0022-1139(00)82655-X

Benzene, toluene, and nitrobenzene interact rapidly with NF4BF4 in anhydrous HF to give, almost exclusively, fluorine substituted aromatic derivatives.Up to four hydrogens can be replaced in a rapid reaction, before a much slower addition reaction takes over.The direction of the substitution in C6H6, C6H5CH3 and C6H5NO2 and the lack of side chain fluorination in C6H5CH3 support an electrophilic substitution mechanism.These rapid substitution reactions are followed by much slower fluorine addition reactions to give the corresponding cyclo-hexadienes and -hexenes.These addition reactions were also studied separately using tetra-, penta-, and hexa- fluorobenzene as the starting materials.In these addition reactions, almost no hydrogen substitution occurred.The addition of the first pair of fluorines always gave 1,4-cyclohexadienes in which the CF2 group was adjacent to hydrogen on the ring.The addition of the second pair of fluorines resulted in the formation of cyclohexenes.These reactions occured in high yield and offer a controlled, high yield path to dienes.All products were characterized spectroscopically and by comparison to literature data.