Phosphinoindenyl and Phosphazidoindenyl Complexes of Lanthanum and Samarium: Synthesis, Characterisation, and Hydroamination Catalysis

The phosphinoindenyl rare-earth metal complexes [1-(Ph2P)-η5-C9H6]2LnIIIN(SiMe3)2, Ln = La (1-La), Sm (1-Sm), were prepared by heating two equivalents of 1-(Ph2P)C9H7 with LnIII[N(SiMe3)2]3 in toluene at 100 °C. The treatment of 1-La with one equivalent of benzonitrile gave (PhCN)[1-(Ph2P)-η5-C9H6]2LaIIIN(SiMe3)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-[BnN3-κN(Ph2)P]-η5-C9H6}{1-[BnN3-κ2N,N’(Ph2)P]C9H6}LnIIIN(SiMe3)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.