| Abstract |
The reaction of H(2)[1,8-dibenzyl-1,4,8,11-tetraazacyclotetradecanel (H(2)Bn(2)CYclam) with 2 equiv of LiBu gives Li(2)Bn(2)Cyclam(L)2 (L = Et(2)O or THF) that reacts with ZrCl(4)(THF)(2) to afford (Bn(2)Cyclam)ZrCl(2) in 40\% yield. Alternatively (Bn(2)Cyclam)ZrCl(2) may be obtained via ZrCl(2)(CH(2)SiMe(3))(2)(Et(2)O)(2) in a significantly higher yield (87\%), avoiding the lithiation of H(2)Bn(2)Cyclam. The syntheses of other H(2)*Bn(2)CYClaM ligand precursors (*Bn = 3,5-dimethylbenzyl and 3,5-di(tert-butyl)benzyl) and the corresponding Zr derivatives (\3,5-Me(2)Bn\(2)-Cyclam)ZrCl(2) and (\3,5-(t)Bu(2)Bn\(2)-Cyclam)ZrCl(2) are also reported. Results on preliminary tests of E-caprolactone and ethylene polymerisation reactions are presented. (C) 2008 Elsevier B.V. All rights reserved. |
