摘要:
A new class of beta-diketiminato derivative dianionic ligands was designed, and three ligand precursors [CH3C(ArNH)CHC(CH3)(NCH2CH2-NHR)] (Ar = 2,6-(Pr-i)(2)C6H3; R = Bu-t (H2M), 2,6-(CH3)(2)C6H3 (H(2)L2), 2,6-(Pr-i)(2)C6H3 (H(2)L3)) were synthesized. The alkane elimination reactions between these ligand precursors and Ln(CH2SiMe3)(3)(THF)(n) provided eight five-coordinate monoalkyllanthanide complexes, in which the ligand serves as a tridentate dianionic donor, with one -CH2SiMe3 and one THF molecule completing the five-coordinate center. These monoalkyl complexes exhibited low to very high catalytic activities for intramolecular hydroamination of 2,2-dimethyl-1-aminopent-4-ene. The catalytic activity increased with increasing metal ion size. For the Nd complex, 98% yield was obtained in 1 h at 60 degrees C with 0.5 mol % catalyst loading.