Enamine chemistry. Part 23. Synthesis, spectral properties, and relative stabilities of cyclic dienamine complexes of tricarbonyliron

Abstract

Reaction of [Fe(CO)₅] and the morpholine and pyrrolidine dienamines of 3,5,5-trimethylcyclohex-2-en-1-one gives a mixture of two tricarbonyl(dienamine)iron complexes. The complex in which the dienamine system is cross-conjugated has been shown to be more stable than that in which the dienamine is linearly conjugated. The reason for this, and the effect on the spectral properties, are discussed.