FUNCTIONALIZATION OF CHLOROBENZENES VIA THEIR CPFE+ SALTS - A SYNTHESIS OF SUBSTITUTED DIPHENYL ETHERS

In work directed towards the synthesis of functionalized diaryl ethers such as SK + F L-94901 the benzylic carbanion derived from 3-ethoxy-6-methylpyridazine-1-oxide was added ortho to an electron-withdrawing chlorine group in (eta-5-cyclopentadienyl)(eta-6-1,4-dichlorobenzene)iron(1+) hexafluorophosphate(1-) and other eta-6-chloroarene cationic complexes to form neutral eta-5-cyclohexadienyl ligands. Oxidative aromatization of the adduct occurred with concomitant demetallation. In contrast to the Yanovsky-type reactions of the carbanion, chloride was displaced from (eta-6-1,4-dichlorobenzene)CpFe+ by phenoxide anions under mild conditions to give eta-6-diphenyl ether cationic complexes.