Pingrong Wei

P–H and P–P bond activation by Ni(I) and Fe(I) β-diketiminato-complexes

Reactions of ((NacNac)Ni)2(µ-η3-η3-C6H5Me) (NacNac = HC(CMeNC6H3(i-Pr)2)2) with PH2Ph or PHPh2 proceeds in a facile manner to afford the Ni(I)–phosphine adducts (NacNac)Ni(PH2Ph) 1 and (NacNac)Ni(PHPh2) 2, respectively. The related reactions of the Fe(I) complex (NacNac)Fe(η2-CH2CPh2) 3 with PH2Ph resulted in the formation of [(NacNac)Fe(µ2-PPh)]24. Alternatively 4 was also obtained from the reaction of [(NacNac)Fe(µ-Cl)]2 with PHPh2 and Na/K. The Ni(II) di-phosphosphine bridged compound [((NacNac)Ni)2(µ4-(PPh)2)] 5 was prepared via reaction of ((NacNac)Ni)2(µ-η3-η3-C6H5Me) with P5Ph5. Crystallographic data are reported for compounds 1–5.

Ti and Zr bidentate bis-phosphinimide complexes

The diphosphines m-C6H4(CH2Pt-Bu2)21 and m-C6H4(CH2PCy2)22 were prepared and oxidized with Me3SiN3 to m-C6H4(CH2(t-Bu2)PNSiMe3)23 and m-C6H4(CH2(Cy2)PNSiMe3)24, and subsequently converted to m-C6H4(CH2(t-Bu)2PNH)25 and m-C6H4(CH2(Cy)2PNH)26. Reaction of 5 and 6 with Ti(NMe2)4 afforded the yellow compounds m-C6H4(CH2(t-Bu)2PN)2Ti(NMe2)27 and m-C6H4(CH2(Cy)2PN)2Ti(NMe2)28, and the low abundance by-product m-C6H4(CH2(t-Bu)2PN)2TiBr(NMe2) 9. In a similar manner, the species m-C6H4(CH2(t-Bu)2PN)2Zr(NEt2)210 was prepared from Zr(NEt2)4. Compounds 8, 9 and 10 were converted to C6H4(CH2(t-Bu)2PN)2TiBr211, m-C6H4(CH2(Cy)2PN)2TiCl213 and C6H4(CH2(t-Bu)2PN)2ZrCl214via reaction with Me3SiX (X = Br, Cl). Alternatively, m-C6H4(CH2(t-Bu)2PN)2TiCl212 and 13 were prepared in low yield from reaction of 3 or 4 with TiCl4. Alkylation of 11 with MeMgBr and PhCH2MgBr proceeded to give m-C6H4(CH2(t-Bu)2PN)2TiMe215 and m-C6H4(CH2(t-Bu)2PN)2Ti(CH2Ph)216, respectively. The species (m-C6H4(CH2(t-Bu)2PN)2)2Zr 17 was prepared from Zr(CH2Ph)4. These synthetic routes are described and the implications for applications in olefin polymerization catalysis are considered. X-Ray structural data for compounds 1, 3, 4, 5, 8, 9 and 16 are reported.

Nickel and palladium phosphinimine-imine ligand complexes

The imine (C6H3i-Pr2)NCMe21 was prepared and used to make the phosphine (C6H3i-Pr2)NC(Me)CH2PPh22. Oxidation with the substituted arylazide resulted in the isolation of the phosphinimine-imine species (C6H3i-Pr2)NC(Me)CH2PPh2(NC6H3i-Pr2) 3. The ligand 3 forms the neutral Ni-complex NiBr2((C6H3i-Pr2)NC(Me)CH2PPh2(NC6H3i-Pr2)) 4 while attempts to prepare the analogous Pd species were unsuccessful. Reaction of 3 with n-BuLi produced the Li-salt Li(thf)((C6H3i-Pr2)NC(Me)CHPPh2(NC6H3i-Pr2)) 5. Subsequent reaction with NiBr2(dme) afforded [Ni((C6H3i-Pr2)NC(Me)CHPPh2(NC6H3i-Pr2))(μ-Br)2Li(thf)2] 6. In related syntheses 5 reacted with NiBr2(dme) or (PhCN)2PdCl2 and PPh3 to give the complexes of formulation MX((C6H3i-Pr2)NC(Me)CHPPh2(NC6H3i-Pr2))(PPh3) (X = Br, M = Ni 7; X = Cl, M = Pd 8). The latter complexes 7 and 8 are phosphinimine-N–C bound. Structural studies of 2 and 4–8 are reported. The implications of these studies for the utility of this phosphinimine-imine ligand in olefin polymerization catalysts are considered.

Metallated triphenylphosphinimine complexes

The reagent [(o-C6H4PPh2NSiMe3)Li]2·Et2O 1 reacted with BCl3 affording (o-C6H4PPh2NSiMe3)BCl24. Similarly reaction of 1 with Me2AlCl resulted in a 1 ∶ 1 mixture of (o-C6H4PPh2NSiMe3)AlMe25 and (o-C6H4PPh2NSiMe3)Al(Me)Cl 6 while the analogous reaction of 1 with GaCl3 gave (o-C6H4PPh2NSiMe3)2Ga(o-C6H4PPh2NH) 7. The analogous compound [Li(o-C6H4PPh2NPh)]2·Et2O 2 was used to make (o-C6H4PPh2NPh)GaCl28, while reaction of 2 with Me2AlCl gave a mixture of [(o-C6H4PPh2NPh)AlCl29 and the salt [(o-C6H4PPh2NPh)2Al][AlMeCl3] 10. The compound 2 also reacts with PdCl2(COD) affording [Pd(o-C6H4PPh2NPh)(μ-Cl)]211 and [Pd(o-C6H4PPh2NPh)2] 12. Similarly, the complexes [Ni(o-C6H4PPh2NPh)2] 13 and [Ni(o-C6H4PPh2N(3,5-C6H3Me2))2] 14 were prepared. The compounds 4–14 have been structurally characterized by X-ray methods.