Synthesis of Monophosphaferrocenes Revisited.

The method of preparing monophosphaferrocenes originally reported by Roberts and Wells, which requires two equivalents of [(mesitylene)FeCp]PF6 (A), was reinvestigated. By the use of inexpensive aluminum chloride as a phenyllithium scavenger, a 50 % reduction of required A could be attained. Diverse monophosphaferrocene derivatives having aliphatic C‐substituents, including four new compounds, were prepared in good yields from the corresponding P‐phenylphospholes, A (1 equiv.), and aluminum chloride (1/3 equiv.) under the modified conditions. These modified conditions showed comparable to better yields of monophosphaferrocenes and the far better atom‐economy compared to the original conditions. [ABSTRACT FROM AUTHOR]