A STUDY OF THE SUBSTITUTION OF SOME FLUOROAROMATICS USING - (E = S or Se) AS A SOURCE OF THE EPh- NUCLEOPHILE

Article abstract of DOI:10.1016/S0022-1139(00)80309-7

A 207Pb NMR study of Pb(SPh)2/DMF mixtures, which are known to act as a source of the SPh^- nucleophile, suggests that they contain species with the Pb^IIS3 kernel.To discover whether the carrier of SPh^- could be ^-, the room-temperature reactions of (AsPh4) (1) with the representative substrates (C6F5)2, 2,4-C6H3(NO2)2F and C6F6 in CHCl3 (or CDCl3/CHCl3) have been investigated.The known compounds 4,4'-(C6F4)2 and 2,4-C6H3(NO2)2(SPh) are formed readily from the first and second substrates, but the conversion of C6F6 to 4-C6F4(SPh)2 is very slow under the conditions used.En-route to 4,4'-(C6F4)2, the new compound 4-C6F5*C6F4(SPh) is formed.For (C6F5)2 and 2,4-C6H3(NO2)2F, analogous but slower reactions are observed using (AsPh4) (2), as a source of SePh^-, but no reaction of C6F6 with 2 was observed.In general, reactions of 2 are complicated by its ease of oxidation to Ph2Se2.