Synthesis of aromatic nitriles using organoiron complexes.

The introduction of cyano groups into arom. sulfones is of interest in light of the potential uses of these materials as monomeric units in the synthesis of engineering thermoplastics. Organoiron complexes (I) were initially prepd. by reaction of p-dichlorobenzenecyclopentadienyliron with various dithiols. The sulfide groups in the bimetallic complexes were oxidized to sulfonyl groups with m-CPBA to give (II) in good yields. Reaction of these diiron complexes with sodium cyanide in DMF resulted in the isolation of the neutral adducts(III). The org. nitriles (IV) were isolated following oxidative demetallation with DDQ. The presence of cyano and sulfonyl groups allowed for facile displacement of the chloro groups with dinucleophilic reagents forming functionalized polyarom. sulfones.