The development of bifunctional chelators (BFCs) for zirconium-89 immuno-PET applications is an area of active research. Herein we report the synthesis and evaluation of octadentate hydroxyisophthalamide ligands (1 and 2) as zirconium-89 chelators. While both radiometal complexes could be prepared quantitatively and with excellent specific activity, preparation of 89Zr-1 required elevated tempe...

A series of 19 different asymmetric catalysts were screened in an effort to identify the first chiral catalyst for the rearrangement of α-hydroxy imines to α-amino ketones involving a 1,2-carbon shift. Although aluminate complexes of VAPOL, VANOL, and 7,7'-(t)Bu2VANOL were quite effective catalysts giving up to 88% ee, the ne plus ultra catalyst for this reaction was found to be a zirconium com...

Herein we detail the synthesis and characterisation of a series of zirconium compounds featuring the bis(amido)silyl ligand [(i)Pr2Si(NDipp)2](2-) (Dipp = 2,6-diisopropylphenyl). The functionalisation of bis(amido)silyl zirconium halide complexes with a variety of nucleophiles, such as LiNMe2, LiBH4 and MeLi, was explored and the resulting products showed a propensity to form anionic zirconate ...

Modification of different zirconium propoxide precursors with H(2)dea was investigated by characterization of the isolated modified species. Upon modification of zirconium n-propoxide and [Zr(O(n)Pr)(O(i)Pr)(3)((i)PrOH)](2) with (1/2) a mol equivalent of H(2)dea the complexes [Zr(2)(O(n)Pr)(6)(OCH(2)CH(2))(2)NH](2) (1) and [Zr(2)(O(n)Pr)(2)(O(i)Pr)(4)(OCH(2)CH(2))(2)NH](2) (2) were obtained. Ho...

A series of salen-type zirconium complexes of the general formula LZrCl2 (L = N,N 0-ethylenebis(salicylideneiminate), 3a; N, N 0-ethylenebis(3,5-di-tert-butylsalicylideneiminate), 3b; N,N 0-ethylenebis(5-methoxysalicylideneiminate), 3c; N,N 0-ethylenebis(5chlorosalicylideneiminate), 3d; N,N 0-ethylenebis(5-nitrosalicylideneiminate), 3e; N,N 0-o-phenylenebis(salicylideneiminate), 4a; N,N 0-o-phe...

Monoand bis(q-cyclopentadieny1)zirconium complexes show interesting stereochemical features with regard to their use in organometallic and organic synthesis as well as in catalysis. An example is described where the zirconocene unit serves to stabilize a planar tetracoordinate carbon center. Next, various building blocks (a metal carbonyl, an organic carbonyl compound, a conjugated diene, plus ...

Zirconium complexes with enolatoimine ligands bearing an electron-withdrawing trifluoromethyl group on the alkoxy moiety [κ²-N,O-{2,6-R₂N=C(CH₃)C(H)=C(O)CF₃]₂ZrCl₂ (2a, R = H; 2b, R = F; 2c, R = CH₃; 2d, R = (i)Pr) were prepared. The isopropyl substituents hinder rotation in solution for 2d, and result in a trans-arrangement of the N-donors in the solid state. Catalyst activities are similar fo...

A new class of chiral zirconium complexes supported by chiral tridentate [O(-)NO(-)]-type of ligands derived from amino acids were synthesized and structurally characterized. They catalyzed asymmetric hydroamination/cyclization of primary aminoalkenes to give five- and six-membered N-heterocyclic amines with up to 94% ee.