Double‐Decker‐Type Dinuclear Nickel Catalyst for Olefin Polymerization: Efficient Incorporation of Functional Co‐monomers

Abstract

Doppeldecker: Ein Nickel‐Zweikernkomplex mit Doppeldeckerstruktur (siehe Schema) und kleinem Ni‐Ni‐Abstand vermittelt die Copolymerisation von Ethylen mit funktionalisierten Monomeren. Das Abstimmen des Ni‐Ni‐Abstands auf die Comonomerstruktur ergibt Polymere mit hohen Comonomerdichten.

A simple and versatile nickel platform for the generation of branched high molecular weight polyolefins

“…In addition, polyethylene with substantially enhanced molecular weights and slightly decreased branching densities were generated (Table 3, entries 9-11). The polymerization activities slightly increased with increasing ethylene pressure ( Table 3, entries [12][13][14]. In addition, the polyethylene molecular weights and polymer branching densities remained constant, which is similar to the results for homogeneous catalyst Ni2.…”

“…1, I) were capable of producing high molecular weight polyethylene with activities rivaling many early transition metal catalysts [7][8][9] . The salicylaldimine nickel catalysts (II) developed by Grubbs and co-workers in 2000 represent another notable advance in this field [10][11][12][13][14] . SHOP-type nickel catalysts (III; SHOP = Shell Higher Olefin Process) have been commercialized for the synthesis of linear α-olefins 15 .…”

Dipalladium Catalyst for Olefin Polymerization: Introduction of Acrylate Units into the Main Chain of Branched Polyethylene

“…The complexes with a cyclic structure show high thermal stability of the catalyst for the polymerization of ethylene and α‐olefins 5. Recently, we reported a dinuclear nickel catalyst with a rigid macrocyclic bis(phenoxyimine) ligand 6. 7 The olefin polymerization by the dinuclear catalysts is enhanced not only by the steric circumstance of an apical site of the metal center but also by the interaction of the polymer end with the other metal 8.…”

Facile Synthesis of 2‐Fluorobenzofurans: 5‐endo‐trig Cyclization of β,β‐Difluoro‐o‐hydroxystyrenes

“…The naphthalene‐based difluorostyrene 4h was obtained from 2h , which was prepared through the MOM‐protection of 1‐naphthol and subsequent formylation ( Scheme 3). [37] The aryl substituents of β,β‐difluoro‐ o ‐hydroxystyrenes 4i – 4k were installed through the Suzuki–Miyaura coupling [38] of the bromine‐bearing MOM‐protected salicylaldehyde 2e and difluorostyrenes 3f with arylboronic acids ( Scheme 4). In addition, β,β‐difluoro‐ o ‐hydroxy‐α‐iodostyrene ( 4l ) was prepared from 1,1,1‐trifluoro‐2‐iodoethane ( 5 , Scheme 5).…”