Highly heteroselective ring-opening polymerization of racemic lactide initiated by divalent ytterbium complexes bearing amino bis(phenolate) ligands.
نویسندگان
چکیده
Polymerization of racemic lactide initiated by divalent ytterbium complexes supported by either dimethylamino-amino bis(phenolate) or methoxy-amino bis(phenolate) ligands proceeds rapidly at room temperature in a living fashion to give heterotactic polylactide with the racemic enchainment of monomer units P(r) ranging from 0.97-0.99.
منابع مشابه
Magnesium complexes containing biphenyl-based tridentate imino-phenolate ligands for ring-opening polymerization of rac-lactide and α-methyltrimethylene carbonate.
A series of racemic 2-[(2'-(dimethylamino)biphenyl-2-ylimino)methyl]-4-R(2)-6-R(1)-phenols (L¹H-L⁴H) were reacted with {Mg[N(SiMe3)2]2}2 to provide four heteroleptic magnesium complexes (L¹⁻⁴)MgN(SiMe3)2·(THF)n (1, R(1) = (t)Bu, R(2) = Me, n = 1; 2, R(1) = R(2) = CMe2Ph, n = 0; 3, R(1) = CPh3, R(2) = (t)Bu, n = 1; 4, R(1) = Br, R(2) = (t)Bu, n = 0), which have been fully characterized. X-ray st...
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A series of racemic 2-[(2′-(dimethylamino)binaphthyl-2-ylimino)methyl]-4-R2-6-R(1)-phenols (L1H–L6H) were reacted with 1 equiv. of Mg[N(SiMe3)2]2 or Zn[N(SiMe3)2]2 to provide three heteroleptic magnesium silylamido complexes [(L4–(6))MgN(SiMe3)2] (4a: R(1) = R(2) = cumyl; 5a: R(1) = CPh3, R(2) = Me; 6a: R(1) = CPh3, R(2) = (t)Bu) and one heteroleptic zinc silylamido complex [(L(4))ZnN(SiMe3)2] ...
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ورودعنوان ژورنال:
- Chemical communications
دوره 48 78 شماره
صفحات -
تاریخ انتشار 2012