Triamidoamine-supported zirconium complexes have been demonstrated to catalyze a range of bond-forming events utilizing arsines. Three different mechanisms have been observed in these reactions. In the first mechanism, triamidoamine-supported zirconium complexes of the general type (N3N)ZrX (N3N =N(CH2CH2NSiMe3)33-; X = monoanionic ligand) catalyzed the dehydrogenative dimerization of diphenyla...

3.1. Overview 2807 3.2. Chiral Aluminum(III) Complexes as a Catalyst 2808 3.2.1. Aluminum(III)-Salen-Based Catalysts 2808 3.2.2. Aluminum(III)-Binaphthol-Based Catalysts 2810 3.3. Chiral Titanium(IV) Complexes as a Catalyst 2814 3.3.1. Titanium(IV)-Peptide-Based Catalysts 2814 3.3.2. Titanium(IV)-Diol-Based Catalysts 2817 3.4. Chiral Zirconium(IV) Complexes as a Catalyst 2818 3.4.1. The Catalyt...

Mono-, di- and trinuclear zirconium hydride species have been isolated in the treatment of amido complexes [Zr(η5-C5Me5)(NMe2)nCl3-n] (n = 3, 1) with amine-borane adducts NHR2BH3 (R2 = Me2, HtBu). The reactions involve the formation of amidoborane ligands with ZrH-B interactions which readily undergo β-hydride elimination to give hydride functions.

Phenylenediamine bis(phenolate) binds in the reduced dianionic form to titanium and zirconium alkoxides giving either mononuclear or bridging dinuclear complexes depending on the metal precursors; the fluxional mononuclear titanium complex is found to exhibit extremely high activity in polymerisation of rac-lactide in the melt.

Bis(imino)phenoxide complexes of zirconium possess spectacular reactivity towards the solvent-free polymerization of cyclic ester monomers and lactides. Polymerization of lactide is living and the resulting product has exceptionally high number average molecular weights (Mn). Polymerization of β-butyrolactone gives syndiotactic poly(3-hydroxybutyrate) with good Mn and molecular weight distribut...

The first synthesis of Salan ligands assembled around the chiral 2,2'-bipyrrolidine backbone is described; as chelation to a metal can only occur via specific faces of the two pyrrolidine nitrogens, these ligands lead to predetermined chirality at metal centres of octahedral titanium and zirconium complexes.

Synthesis of Fmoc-protected N(δ)-acetyl-N(δ)-(tert-butoxy)-l-ornithine has revealed it to be a metal-chelating amino-acid precursor. This protected amino acid was compatible with the preparation of ferrichrome peptides by standard Fmoc-based solid-phase peptide synthesis. Evaluation of deferriferrichrysin for metal ion chelation revealed that zirconium(IV) and titanium(IV) formed complexes with...

Octahedral titanium and zirconium complexes based on salicyloxazoline ligands with sterically demanding ortho-substituents provide a new family of extremely active ethene polymerization catalysts [up to 10(8) g PE (mol bar h)(-1)] which are in some cases "single site".

Title of Document: Synthesis, Stability, and Reactivity of High Oxidation State Pentamethylcyclopentadienyl Acetamidinate β-Hydrideor β-Methide-Bearing Alkyl Complexes of Zirconium, Titanium, and Tantalum Albert Epshteyn, Doctor of Philosophy, 2006 Directed By: Professor Lawrence R. Sita Department of Chemistry and Biochemsitry University of Maryland, College Park, MD 20740 In the course of stu...

Seven lithium complexes supported by sterically and electronically diverse phenoxyimine ligands were synthesized characterized X-ray diffraction, NMR spectroscopy elemental microanalysis. These show high activity (kobs ≤7.43×10−2 s−1) for rac-lactide ring-opening polymerization (ROP) in the presence of co-initiator benzyl alcohol (BnOH), with exception Li4 which features an unusual polymeric la...