| Abstract
| - Complexes (Cp-PPh2)2ZrX2 (X = Cl, CH3) react with Pd(II) or Rh(I) complexes to yield early−late heterodimetallic complexes, some of which show promising catalytic features (cross-coupling; hydroformylation).
- (Cp-PPh2)2ZrCl2 (5) reacts with (PhCN)2PdCl2 to yield the early−late heterodimetalliccomplex [(Cp-PPh2)2ZrCl2/PdCl2], 7, which was characterized by an X-ray crystal structureanalysis. The phosphine-substituted bent metallocene moiety in 7 serves as a conformationally flexible chelate phosphine ligand (angle P−Pd−P: 96.46(3)°). Complex 7 is an activecatalyst for the cross-coupling of sec-butylmagnesium bromide with bromobenzene, leadingto excellent regioselectivity and moderate reactivity. Complex 5 reacts with dicarbonylrhodium chloride dimer (0.5 equiv) to yield the triply bridged complex 12, [ClZr(μ-Cp-PPh2)2(μ-Cl)Rh(CO)Cl], which was also characterized by X-ray diffraction (the angle P−Rh−P is158° at the distorted square-pyramidal pentacoordinated rhodium center). (Cp-PPh2)2Zr(CH3)2 (13) reacts with [H(CO)Rh(PPh3)3] (14) with loss of two PPh3 ligands and instantaneous liberation of methane to form complex 15, [CH3Zr(μ-Cp-PPh2)2Rh(CO)PPh3](Zr−Rh),which probably contains a metal−metal bond between the early and late transition metal.Complex 15 is a very active 1-hexene hydroformylation catalyst (TOF > 600, n/iso ≈ 3 at80 °C).
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