Reactivity studies of methylzirconocene phosphide complexes
The reaction of Cp2ZrMe(PHR) with benzophenone, cyclohexanone, acetone, benzaldehyde, and benzophenone results in the insertion of the organic substrate into the Zr-P bond. In this way, the complexes Cp2ZrMe(OCPh2PH(C6H2-2,4,6-t-Bu 3)) (3), Cp2ZrMe(OC6H10PH(C6H 2-2,4,6-t-Bu3)) (4), Cp2ZrMe(OCMe2PHR) (R = (C6H2-2,4,6-t-Bu3) (5), R = (C6H2-2,4,6-Me3) (8), and Cp2ZrMe(NC(Ph)PH(C6H2-2,4,6-t-Bu3)) (6) were prepared. The species Cp2ZrMe(PH-(C6H2-2,4,6-Me3)) (7) was also formed in the reaction of Cp2ZrMe2 with H2P(C6H2-2,4,6-Me3); however, 7 reacted further with Cp2ZrMe2 to give the bimetallic species (Cp2ZrMe)2(μ-P(C6H2-2,4,6-Me 3) (9). In the analogous reaction of Cp2ZrMe2 with 1 equiv of H2P(C6H2-2,4,6-Me3), the species (Cp2Zr)(Cp2ZrPH(C6H2-2,4,6-Me 3))(μ-P6H2-2,4,6-Me 3))(μ-η1-η5-C5H 4) (11) was obtained. Compound 11, which results from cyclopentadienyl C-H bond activation, was also formed directly from degradation of the unstable terminal phosphinidene species Cp2Zr(P(C6H2-2,4,6-Me3))(PMe 3) (12). The implications of this chemistry are considered and discussed. Compound 3, 9, and 11 have been characterized crystallographically.
Breen, Tricia L. and Stephan, Douglas W.. (1996). Reactivity studies of methylzirconocene phosphide complexes. Organometallics, 15 (21), 4509-4514.