Copolymerization of Propylene and Polar Allyl Monomer with Zirconocene/Methylaluminoxane Catalyst:  Catalytic Synthesis of Amino-Terminated Isotactic Polypropylene

Abstract

The copolymerizations of propylene with allyl monomers carrying alcohol or amine were conducted by the rac-dimethylsilylbis(1-indenyl)zirconium dichloride/methylaluminoxane catalyst system. The allyl monomers were pretreated by alkylaluminum before the polymerization. Although the efficiency of the introduction of allyl alcohol-based comonomer was extraordinary low (0.04−0.08 mol % in polymer), the trimethylaluminum-treated allylamine was found to be introduced more effectively (0.65 mol % in polymer). The 13C NMR study indicated that the position of allylamine unit in the copolymer was influenced by the kind of alkylaluminum used at the polymerization. In the presence of trimethylaluminum, the terminally aminated polypropylene was obtained ([amino end polymer]/[whole polymer] = 0.83). In the presence of triisobutylaluminum, however, the allylamine unit is located both on the main chain and at the chain end. The end-aminated polymer was probably obtained due to the formation of dormant species after the insertion of the comonomer followed by the chain transfer to alkylaluminum.

Preparation of Polar Ethylene–Norbornene Copolymers by Metallocene Terpolymerization with Triisobutylaluminium‐Protected But‐3‐en‐1‐ol

“…Recently, the synthesis of polymers end‐functionalized with polar α ‐olefins that have short methylene spacers (e.g., allyl alcohol, allylamine, and but‐3‐en‐1‐ol) has attracted much attention. As reported by Imuta and Hagihara,20–23 the end‐functionalized polyolefins could be obtained through formation of dormant species by insertion of a functional allyl‐based comonomer, followed by chain transfer to alkyl aluminum. In this paper, we report the terpolymerization of ethylene and norbornene in the presence of but‐3‐en‐1‐ol with a metallocene/MAO catalyst system.…”

Nickel‐Catalyzed Allylmethylation of Alkynes with Allylic Alcohols and AlMe3: Facile Access to Skipped Dienes and Trienes

“…On the basis of the above observations, we propose the following mechanism for this nickel-catalyzed allylmethylation reaction (Scheme 6): When AlMe 3 was slowly added into the reaction mixture, it reacted quickly with the allylic alcohol, as evidenced by violent effervescence (methane gas). Two possible alkoxyaluminum species, allyloxydimethylaluminum (ADMAL) and bis(allyloxy)methylaluminum (BAMAL), could be formed, [17] which would react with Ni 0 to give p-allynickel intermediate A or its dimer form. [18] Next, carbonickelation of the internal alkyne with A formed the vinyl nickel species B.…”

“…Ligands exerted a slight influence on this model reaction. The use of various mono-or bisphosphine ligands led to lower yields for 2 a formation (entries [12][13][14][15][16][17][18]. Different nickel precursors were also examined, all of which led to a lower yield of 2 a (entries 19-22).…”

The Effect of SiMe3 and SiEt3Para Substituents for High Activity and Introduction of a Hydroxy Group in Ethylene Copolymerization Catalyzed by Phenoxide‐Modified Half‐Titanocenes

“…[1,2] In particular, development of the molecular catalysts, which enable synthesis of new copolymers (containing sterically encumbered monomers or cyclic olefins that are not incorporated by ordinary catalysts, [3,4] or by incorporation of polar functionalities [5][6][7][8][9][10] ), have been considered as the fascinating goals. Efficient synthesis of high-molecularweight ethylene (propylene) copolymers containing a hydroxy group has been the attractive target in early transition-metal catalysis, [7][8][9] because the polymerization generally proceeds with low catalytic activities affording (rather) low molecular weight polymers owing to a strong interaction of oxygen with the centered metal, [7][8][9] even though the OH group in alken-1ol was protected with a trialkylsilyl group [7c,d] or for example Al i Bu 3 in advance. [7][8][9] The direct ethylene copolymerization using nickel, palladium catalysts generally afforded copolymers with certain branching.…”