Synthesis, structure, and catalytic activity of binuclear lanthanide complexes with chiral NOBIN-based NNO ligands

Two new amido binuclear complexes {(1)YN(SiMe3)(2)}(2) center dot C7H8 (3 center dot C7H8) and {(2)SmN(SiMe3)(2)}(2) center dot C6H14 (4 center dot C6H14) have been readily prepared in good yields by amine elimination reaction between Ln[N(SiMe3)(2)](3) (Ln = Sm, Y) and chiral NNO ligands, (S)-2-(pyridin-2-ylmethylamino)-2'-hydroxy-1,1'-binaphthyl (1H(2)) and (S)-5,5',6,6',7,7',8,8'-octahydro-2-(pyrrol-2-ylmethyleneamino)-2'-hydroxy-1,1'-binaphthyl (2H(2)), respectively. They both have been characterized by various spectroscopic techniques, elemental analyses, and X-ray diffraction analyses. They are active catalysts for asymmetric hydroamination/cyclization of aminoalkenes and ring-opening polymerization of rac-lactide, affording cyclic amines in excellent conversions with moderate ee values and isotactic-rich polylactides, respectively. (C) 2008 Elsevier B.V. All rights reserved.