Synthesis and Structure of Group 4 Symmetric Amidinate Complexes and Their Reactivity in the Polymerization of α-Olefins

Abstract

The steric properties of various nitrogen substituents on amidines were tuned in order to obtain group 4 mono- and bis(amidinate) dimethylamido or chloride complexes. The amidinate dimethylamido and chloride complexes were prepared, and their solid-state as well as their solution-state structures were studied. After the activation by MAO, these complexes were tested in the polymerization of propylene and ethylene. A noticeable influence of the amidine carbon and nitrogen substituents on the activity of the catalyst and properties of the obtained polymer was observed. Further, a plausible mechanism for the ethylene polymerization process is presented taking into account a combination of ESR-C60 and MALDI-TOF experiments, shedding light on the nature of the catalytic species.

Hydroaminoalkylation of Allylsilanes and a One‐Pot Procedure for the Synthesis of 1,5‐Benzoazasilepines

“…The corresponding reactions equence includes an initial hydroaminoalkylation of an allyl (2-bromophenyl)silane and as ubsequenti ntramolecular Buchwald-Hartwig amination. Catalyst IV, [17] the N-methylanilines, and the allylsilanes were synthesized according to literature procedures. However,t he corresponding results will be published separately in due course.…”

Generation of TiII Alkyne Trimerization Catalysts in the Absence of Strong Metal Reductants

“…First, N , N ′-(2,6- i Pr 2 Ph) 2 formamidine 42 (454 mg, 1.25 mmol, 2.1 equiv), KBn (162 mg, 1.25 mmol, 2.1 equiv), and 2 mL of THF were added to a 20 mL scintillation vial equipped with a small stirbar in a N 2 -filled glovebox. This was stirred at room temperature for 10 min until a colorless solution formed.…”

Group 4 metal complexes for homogeneous olefin polymerisation: a short tutorial review

“…Other Tp-supported Group 4 polyolefin catalysts have also been investigated by other groups [89][90][91][92]. In addition, Group 4 non-cyclopentadienyl catalysts supported by j 2 N,N 0 -amidinate ligands have also been reported [93][94][95][96].…”