The Intermediacy of Free Aryl Radicals in the Reaction of o-Alkenyloxybenzenediazonium Salts With Ferrocene

Abstract

The formation of 3-ferrocenylmethyl-2,3-dihydrobenzofuran (5a) and similar products bearing cyclized substituents, when ferrocene or mixtures of ferrocene and ferrocenium ion are treated witho - allyloxybenzene - or o-but-3-enyloxybenzene-dimonium salts, provides unequivocal evidence for the intermediacy of free aryl radicals in the reaction of ferrocene with arenediazonium salts. The results are consistent with a mechanism involving electron transfer and dediazoniation followed by homolytic attack on ferroce nium ion.