Regioselective Insertion of Aluminum(I) in the <i>cyclo</i>‐P<sub>5</sub> Ring of Pentaphosphaferrocene
Ravi Yadav, Thomas Simler, Bhupendra Goswami, Christoph Schoo, Ralf Köppe, Subhayan Dey, Peter W. Roesky
Abstract
Abstract A route to directly access mixed Al–Fe polyphosphide complexes was developed. The reactivity of pentaphosphaferrocene, [Cp*Fe( η 5 ‐P 5 )] (Cp*=C 5 Me 5 ), with two different low‐valent aluminum compounds was investigated. The steric and electronic environment around the [Al I ] centre are found to be crucial for the formation of the resulting Al–Fe polyphosphides. Reaction with the sterically demanding [Dipp‐ BDI Al I ] (Dipp‐ BDI ={[2,6‐ i Pr 2 C 6 H 3 NCMe] 2 CH} − ) resulted in the first Al‐based neutral triple‐decker type polyphosphide complex. For [(Cp*Al I ) 4 ], an unprecedented regioselective insertion of three [Cp*Al III ] 2+ moieties into two adjacent P−P bonds of the cyclo ‐P 5 ring of [Cp*Fe(η 5 ‐P 5 )] was observed. The regioselectivity of the insertion reaction could be rationalized by isolating an analogue of the reaction intermediate stabilized by a strong σ‐donor carbene.