REACTIONS OF FERROCENE AND ACETYLFERROCENE WITH CARBON-CENTERED FREE-RADICALS

Homolytic substitutions of ferrocene with a variety of carbon-centered radicals have been investigated. Reactions with synthetic utility have only been obtained in the cases of ambiphilic radicals (cyanomethyl and alkoxycarbonylmethyl), whereas nucleophilic radicals (R. and RCO.) give relatively low yields, and no reaction at all is observed with electrophilic radicals (malonyl, methylmalonyl). The reaction of acetylferrocene with cyanomethyl and ethoxycarbonylmethyl radicals leads to the formation of homo- and heteroannular disubstituted products. The mechanistic implications of these results are discussed.