Coordination-Insertion Copolymerization of Norbornene with α-Olefins using Half-Titanocene Phosphinimide Catalyst
Year: 2026
Type: preprint
Abstract: We previously reported the controlled coordination-insertion polymerization of 2-norbornene (NB) and 5-alkyl-2-norbornenes using a phosphinimide-ligated half-titanocene catalyst (1), affording high-molecular-weight polymers. In this study, the copolymerization of NB with α-olefins, including 1-octene (2), 1-octadecene (3), and 10-undecen-1-ol (4), was investigated to explore the monomer scope and functional group tolerance. Copolymers with Mn values ranging from 2.0 to 20 kg/mol were obtained in moderate to high yields. NB was consumed more rapidly than 2. Nuclear magnetic resonance (NMR) analysis of the copolymers suggests that an α-olefin-derived titanium alkyl species undergoes chain transfer via a σ-bond metathesis with NB, affording the 2-norbornenyl moiety at the initiating chain end. In addition, copolymers containing up to 7 mol% of 4 were obtained through protecting the hydroxyl group with methylaluminoxane (MAO) prior to polymerization. Collectively, catalyst 1 exhibited broad reactivity, including the coordination-insertion and the σ-bond metathesis reactions, while remaining catalytically active in the presence of the alkoxyaluminum species.
Source: ChemRxiv
Authors: Taiki Inoko, Shin-ichi Matsuoka
Institution: Nagoya Institute of Technology
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7221159179