Cationic 1-substituted-dicarbonyl(η5-4-methoxycyclohexadienyl)-(triphenylphosphine)iron complexes 10 from a new class of highly functionalised iron complexes which have never been described. They were obtained from neutral 1-substituted(η4-4-methoxy-1,3-cyclohexadiene)Fe(CO)2PPh3 iron complexes 9, prepared by ligand exchange reaction under improved experimental conditions. A quaternary carbon was formed