We wish to report a preliminary investigation of an organometallic system which promises to be a versatile tool for the synthesis of organic species, particularly cis-allylphosphonium salts, from conjugated dienes. This system involves the use of a-allyliron tetracarbonyl cations, readily available in high yield from the appropriate diene iron tricarbonyl complex by protonation (HBF4) in the presence of carbon monoxide.'These cationic species are ...
