Synthesis of Monophosphaferrocenes Revisited

Abstract

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.

Synthesis, structure and electrochemical properties of 3,4,5-triaryl-1,2-diphosphaferrocenes

“…Among phosphaferrocenes, 1-mono-, 25 1,2,3-tri-, 26,27 1,2,4-tri- 28 and pentaphosphaferrocene 24,29 derivatives are currently the most investigated. In contrast, 1,2-diphosphaferrocenes have received comparatively less attention due to the absence of simple and effective rational synthetic routes, as the only known approaches are associated with multistep synthesis, side reactions and moderate yields (12–28%).…”

Synthesis, Structure, and Electrochemical Properties of 2,3,4,5-Tetraphenyl-1-Monophosphaferrocene Derivatives

“…However, phenyllithium PhLi is an undesirable by-product, the deactivation of which is necessary. This method has recently been modified by the use of inexpensive aluminum chloride as an in situ-generated phenyllithium scavenger, and thus a 50% yield of desired [(η 6 -mesitylene)FeCp]PF 6 was attained [ 25 ].…”

Effect of Phosphorus Substitution in the Cyclopentadienyl Ring of Ferrocene: Combined Mössbauer Spectroscopy and DFT Studies

“…The most intriguing feature of these complexes is the presence of energetically and sterically accessible lone pairs at each heteroatom. Among the various heteroelement derivatives reported to date, phosphaferrocenes are by far the most investigated. − The introduction of a phosphorus atom into the ferrocene backbone allows access to novel supramolecular complexes and coordination polymers of multidimensional topology with mixed σ/π coordination modes, which are not typical for the classical ferrocene species. − Additionally, monophosphaferrocenes − and pentaphosphaferrocenes have been applied in asymmetric homogeneous catalysis and synthesis of asymmetric phosphines, revealing the practical value of phosphaferrocenes. A better understanding of how the replacement of CH-units by phosphorus atoms affects the properties of ferrocene will lead to the effective design of new systems.…”