A Comparison of Cationic Zirconium Methyl and Isobutyl Initiators that Contain an Arylated Diamido-Pyridine Ligand for Polymerization of 1-Hexene. Elucidation of a Dramatic “Initiator Effect”

Evaluation of (η5‐C5Me5)Hf(R)2[N(Et)C(Me)N(t‐Bu)] (R=Me and i‐Bu) for the Stereospecific Living and Degenerative Transfer Living Ziegler–Natta Polymerization of α‐Olefins

“…Schrock and co-workers [7] have previously identified a pronounced "initiator effect" for their zirconium-based living Ziegler-Natta polymerization in which attempts to prepare the cationic zirconium methyl initiator, { 2 . In order to investigate whether a similar initiator effect might be possible in the present system, the diisobutyl derivative 3b was prepared in two steps using conventional salt-elimination methodology as shown in Scheme 1.…”

Zirconium‐Catalyzed Multistep Reaction of Hydrazines with Alkynes: A Non‐Fischer‐Type Pathway to Indoles

“…The corresponding metallacyclic complexes 6 a,b containing an Narylated ancillary tripod ligand were obtained by reaction of the (bis)dimethylamido complex 5 [10] with one molar equivalent of both the alkyne and diphenylhydrazine.…”

Catalytic polymerization of ethylene by non-metallocene Zirconium(IV) calix[4] pyrrole complexes

“…Currently non-cyclopentadienyl ligands which include diamido are being explored for the design of olefin polymerization catalysts based on group 4 transition metal complexes [3,4]. Commonly, metal chloride derivatives have been used in combination with co-catalyst's methylaluminoxane (MAO) as catalyst precursors in large excess, but metal-alkyls have also attracted much attention.…”

“…Performances in some instances improved with using stoichiometric amounts of co-catalysts such as BðC 6 F 5 Þ 3 [5]. In recent years, the synthesis and catalytic polymerization properties of Zr(IV)dichloride, diamido ligands based on the 2-aminobenzylamine framework [6] and dibenzyl derivatives [4] have reported.…”