Reactivity of Allenes towards Iron Carbonyl Complexes

Abstract

A series of monosubstituted allenes was reacted with Fe₂(CO)₉ to give dinuclear iron-carbonyl complexes containing organic ligands derived either from monomeric or dimerized allene. A mechanism of formation is proposed based on isolated intermediates. These intermediates point to an allene dimerization via addition of a reactive allene iron complex to free allene. Unusual chemical shifts were observed for many resonances in the ¹H- and ¹³C-NMR spectra of the new compounds.