Coordination-Insertion Copolymerization of Norbornene with α-Olefins using Half-Titanocene Phosphinimide Catalyst
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.
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BibTeX
@misc{inoko2026coordinationinsertion,
title = {{Coordination-Insertion Copolymerization of Norbornene with α-Olefins using Half-Titanocene Phosphinimide Catalyst}},
author = {Taiki Inoko and Shin-ichi Matsuoka},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010152/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010152/v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Coordination-Insertion Copolymerization of Norbornene with α-Olefins using Half-Titanocene Phosphinimide Catalyst
AU - Taiki Inoko
AU - Shin-ichi Matsuoka
PY - 2026
DA - 2026/10/09
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010152/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010152/v1
AB - 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.
ER -