The synthesis of α-N,N-dimethyl-1′-diphenylphosphinoferrocenylethylamine and related ligands

Abstract

Routes to the title compound were explored based on the cleavage of [1]-ferrocenophanes with aryllithium. Thus the cleavage of [Formula: see text] with phenyllithium affords (η5-C5H4Li)Fe(η5-C5H3(CHMeNMe2)PPh2) and η5-C5H4PPh2)Fe(η5-C5H3Li(CHMeNMe2)) in the ratio 15:85. Hydrolysis of this mixture affords the title compound 4. The lithio-ferrocenes can be treated with XER2 to yield other mixed ligands (E = As, P).A route to 4 via (η5-C5H4PPh2)Fe(η5-C5H4C(O)Me) was also established but it is complicated by low yields and many side products such as [(η5-C5H4PPh2)Fe(η5-C5H4)]2C=CH2.