Multifaceted Chemistry with Phosphorus-Functionalised Ferrocene Derivatives

Abstract: Cyclopentadienes with a P-functionalised alkyl or aryl side chain are useful precursors for mono- and dianionic bifunctional ligands in main group and transition metal chemistry. We have developed two synthetic approaches for several (chiral) phosphanylalkyl or -aryl cyclopentadienyl complexes: a) employing lithium phosphanylalkyl- and -arylcyclopenta- dienides, such as Li[(C5H4)-X-PR1R2] [R1 = H, alkyl, aryl; R2 = alkyl, aryl; X = alkylene, arylene], as transfer reagents for the organic ligand, and b) by modification of the metal- bound cyclopentadienyl ring in ferrocenes.

Primary (Figure 1) and secondary ferrocenyl phosphines were obtained by method b). These phosphines display interesting reactivity and can be used as starting materials for further functionalisation of the phosphanyl group or for ferrocenyl-substituted P-B-based polymers (Figure 2).

Tertiary ferrocenyl phosphines, such as 1,2-disubstituted aryl-based ferrocenyl phosphines, have applications in catalytic reactions. The corresponding 1,1’- or 1,1’,2-substituted ferrocenes (Figure 3) can be used for immobilisation of the respective ferrocene derivatives, for example on dendrimers.

Synthetic routes to these ferrocenyl phosphines, their properties and applications will be discussed.

About the speaker: Evamarie Hey-Hawkins has been a Full Professor of Inorganic Chemistry at Universität Leipzig, Germany, since 1993. She received her diploma (1982) and doctoral degree (1983) at the University of Marburg, Germany. After stays at the University of Sussex, UK, the University of Western Australia and the Australian National University, Canberra, Australia, she returned to Germany and completed her habilitation (in Marburg, 1988). Prof. Hey-Hawkins is a fellow of the Royal Society of Chemistry (FRSC) and a member of several Editorial Boards and the International Advisory Boards. She has been the Chair of the “European Phosphorus Sciences Network” and currently chairing a new network program on “Smart Inorganic Polymers”. She is the Speaker of the Graduate School “Building with Molecules and Nano-objects (BuildMoNa)”. Her scientific interests are manifold and comprise inorganic chemistry/organometallic chemistry, organophosphorus chemistry, biologically active boron compounds, heterometallic transition metal complexes and catalysis. She has authored more than 420 publications in refereed journals.