Insertion Reactions of Neutral Phosphidozirconocene Complexes as a Convenient Entry into Frustrated Lewis Pair Territory

Neutral phosphidozirconocene complexes [Cp 2 Zr(PR 2 )Me] (Cp=cyclopentadienyl; 1a : R=cyclohexyl (Cy); 1b : R=mesityl (Mes); 1c : R= t Bu) undergo insertion into the Zr−P bond by non‐enolisable carbonyl building blocks (O=CR′R′′), such as benzophenone, aldehydes, paraformaldehyde or CO 2 , to give [Cp 2 Zr(OCR′R′′PR 2 )Me] ( 3 – 7 ). Depending on the steric bulk around P, complexes 3 – 7 react with B(C 6 F 5 ) 3 to give O‐bridged cationic zirconocene dimers that display typical frustrated Lewis pair (FLP)/ambiphilic ligand behaviour. Thus, the reaction of {[Cp 2 Zr(μ‐OCHPhPCy 2 )][MeB(C 6 F 5 ) 3 ]} 2 ( 10a ) with chalcone results in 1,4 addition of the Zr + /P FLP, whereas the reaction of {[Cp 2 Zr(μ‐OCHFcPCy 2 )][MeB(C 6 F 5 ) 3 ]} 2 ( 11a ; Fc=(C 5 H 4 )CpFe) with [Pd( η 3 ‐C 3 H 5 )Cl] 2 yields the unique Zr−Fe−Pd trimetallic complex 13a , which has been characterised by XRD analysis.