Effect of nature of the nucleophile on the mechanism of nucleophilic aromatic substitution reactions involving fluorenyl and trimethylstannyl anions

1.	The kinetics of reactions of alkali metal salts of 9-carbomethoxy- and 9-cyanofluorene with para-nitrofluorobenzene and of Me3SnM with pentafluoropyridine have been studied.
2.	In the case of carbanions the free anions are more reactive, while in the case of Me3SnM the corresponding tight (contact) ion pairs are more reactive.
3.	The effect of the leaving group (on reactivity) was investigated using the reactions of pentafluorochlorobenzene with the K salts of 9-carbomethoxyfluorene and cyclopentadienylirondicarbonyl anions as examples.
4.	The reaction mechanism has been shown to depend on the nature of the nucleophile.

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2826–2832, December, 1988.