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Ring-Opening Metathesis Polymerization and Related Olefin Metathesis Reactions in Benzotrifluoride as an Environmentally Advantageous Medium. Int J Mol Sci 2022; 24:ijms24010671. [PMID: 36614111 PMCID: PMC9820898 DOI: 10.3390/ijms24010671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 12/23/2022] [Accepted: 12/23/2022] [Indexed: 01/03/2023] Open
Abstract
A tremendous number of solvents, either as liquids or vapors, contaminate the environment on a daily basis worldwide. Olefin metathesis, which has been widely used as high-yielding protocols for ring-opening metathesis polymerization (ROMP), ring-closing metathesis (RCM), and isomerization reactions, is typically performed in toxic and volatile solvents such as dichloromethane. In this study, the results of our systematic experiments with the Grubbs G1, G2, and Hoveyda-Grubbs HG2 catalysts proved that benzotrifluoride (BTF) can replace dichloromethane (DCM) in these reactions, providing high yields and similar or even higher reaction rates in certain cases. The ROMP of norbornene resulted not only in high yields but also in polynorbornenes with a high molecular weight at low catalyst loadings. Ring-closing metathesis (RCM) experiments proved that, with the exception of the G1 catalyst, RCM occurs with similar high efficiencies in BTF as in DCM. It was found that isomerization of (Z)-but-2-ene-1,4-diyl diacetate with the G2 and HG2 catalysts proceeds at significantly higher initial rates in BTF than in DCM, leading to rapid isomerization with high yields in a short time. Overall, BTF is a suitable solvent for olefin metathesis, such as polymer syntheses by ROMP and the ring-closing and isomerization reactions.
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Lee GS, Lee HW, Lee HS, Do T, Do JL, Lim J, Peterson GI, Friščić T, Kim JG. Mechanochemical ring-opening metathesis polymerization: development, scope, and mechano-exclusive polymer synthesis. Chem Sci 2022; 13:11496-11505. [PMID: 36320385 PMCID: PMC9557243 DOI: 10.1039/d2sc02536a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/31/2022] [Indexed: 11/28/2022] Open
Abstract
Ruthenium-alkylidene initiated ring-opening metathesis polymerization has been realized under solid-state conditions by employing a mechanochemical ball milling method. This method promotes greenness and broadens the scope to include mechano-exclusive products. The carbene- and pyridine-based Grubbs 3rd-generation complex outperformed other catalysts and maintained similar mechanistic features of solution-phase reactions. High-speed ball milling provides sufficient mixing and energy to the solid reaction mixture, which is composed of an initiator and monomers, to minimize or eliminate the use of solvents. Therefore, the solubility and miscibility of monomers and Ru-initiators are not limiting factors in solid-state ball milling. A wide variety of solid monomers, including ionomers, fluorous monomers, and macromonomers, were successfully polymerized under ball milling conditions. Importantly, direct copolymerization of immiscible (ionic/hydrophobic) monomers exemplifies the synthesis of mechano-exclusive polymers that are difficult to make using traditional solution procedures. Finally, the addition of a small amount of a liquid additive (i.e., liquid-assisted grinding) minimized chain-degradation, enabling high-molecular-weight polymer synthesis. Mechanochemical ball-milling ring-opening metathesis polymerization minimized solvent use and produced previously inaccessible polymers in solution.![]()
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Affiliation(s)
- Gue Seon Lee
- Department of Chemistry and Research Institute of Physics and Chemistry, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Hyo Won Lee
- Department of Chemistry and Research Institute of Physics and Chemistry, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Hyun Sub Lee
- Department of Chemistry and Research Institute of Physics and Chemistry, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Taeyang Do
- Department of Chemistry and Research Institute of Physics and Chemistry, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Jean-Louis Do
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, H3A0B8 Montreal, Canada
| | - Jeewoo Lim
- Department of Chemistry and Research Institute for Basic Science, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Gregory I. Peterson
- Department of Chemistry, Inchon National University, Incheon, 22012, Republic of Korea
| | - Tomislav Friščić
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, H3A0B8 Montreal, Canada
| | - Jeung Gon Kim
- Department of Chemistry and Research Institute of Physics and Chemistry, Jeonbuk National University, Jeonju, 54896, Republic of Korea
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk, 55324, Republic of Korea
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