Synlett 2024; 35(10): 1127-1130
DOI: 10.1055/s-0043-1763653
cluster
Thieme Chemistry Journals Awardees 2023

Evaluating Catalyst Performance in Synthesizing Hydroxyl-Terminated Polybutadiene by Ring-Opening-Metathesis Polymerization

Gillian A. Su
,
Paul Reiter
,
The authors wish to acknowledge financial support from DEVCOM ARL through cooperative agreement W911NF-20-2-0052. This work was made possible by the use of Virginia Tech’s Nuclear Magnetic Resonance Facility, which is supported by the Department of Chemistry at Virginia Tech.


Abstract

Hydroxyl-terminated polybutadiene (HTPB) can be synthesized by ring-opening metathesis polymerization (ROMP) in a one-step process using cyclooctadiene in the presence of a hydroxyl-functionalized chain-transfer agent (CTA). However, previous studies have shown that the presence of primary alcohols can lead to the degradation of some ruthenium catalysts and that the hydroxyl end groups may be converted into aldehydes. Here we compare the performance of five ruthenium-based catalysts — Grubbs first-, second-, and third-generation catalysts (G1, G2, and G3, respectively), Hoveyda–Grubbs Z-selective catalyst (HGZ), and Hoveyda–Grubbs second-generation catalyst (HG2) — in ROMP with a CTA containing primary alcohols. We found that HTPB can be rapidly synthesized in a single step using G3 while avoiding end-group isomerization (2.2% aldehyde formation after full conversion is reached in 5 min). This result suggests that G3 may enable a more effective approach to synthesizing HTPB that avoids protecting groups but still maintains high end-group fidelity.

Supporting Information



Publication History

Received: 02 October 2023

Accepted after revision: 13 November 2023

Article published online:
15 December 2023

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