Phosphinoindenyl and phosphazidoindenyl complexes of lanthanum and samarium: synthesis, characterisation, and hydroamination catalysis

The phosphinoindenyl rare-earth metal complexes [1-(Ph(2)P)-η(5)-C(9)H(6)](2)Ln(III)N(SiMe(3))(2), Ln = La (1-La), Sm (1-Sm), were prepared by heating two equivalents of 1-(Ph(2)P)C(9)H(7) with Ln(III)[N(SiMe(3))(2)](3) in toluene at 100 °C. The treatment of 1-La with one equivalent of benzonitrile gave (PhCN)[1-(Ph(2)P)-η(5)-C(9)H(6)](2)La(III)N(SiMe(3))(2), 2, while no adduct was formed in case of the samarium derivative 1-Sm. The reaction of 1-La and 1-Sm with two equivalents of benzyl azide yielded the (phosphazido)indenyl complexes {1-[BnN(3)-κN(Ph(2))P]-η(5)-C(9)H(6)}{1-[BnN(3)-κ(2)N,N′(Ph(2))P]C(9)H(6)}Ln(III)N(SiMe(3))(2), Ln = La (3-La), Sm (3-Sm), respectively. The five complexes catalyse the intramolecular hydroamination/cyclisation of 2,2-diphenylpent-4-ene-1-amine using 2% catalyst loading. All compounds were characterised by NMR and UV-Vis spectroscopy, single-crystal X-ray diffraction, and elemental analysis and DFT calculations were performed for 3-La.