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Recyclable and efficient polyurethane-Ir catalysts for direct borylation of aromatic compounds
| Title: | Recyclable and efficient polyurethane-Ir catalysts for direct borylation of aromatic compounds |
| Authors: | Kimura, Akihiro Browse this author | | Hayama, Haruka Browse this author | | Hasegawa, Jun-ya Browse this author →KAKEN DB | | Nageh, Hassan Browse this author | | Wang, Yue Browse this author | | Naga, Naofumi Browse this author | | Nishida, Mayumi Browse this author | | Nakano, Tamaki Browse this author →KAKEN DB |
| Issue Date: | 21-Dec-2017 |
| Publisher: | Royal Society of Chemistry |
| Journal Title: | Polymer chemistry |
| Volume: | 8 |
| Issue: | 47 |
| Start Page: | 7406 |
| End Page: | 7415 |
| Publisher DOI: | 10.1039/c7py01509g |
| Abstract: | Four polyurethanes comprising 2,2'-bipyridyl moieties incorporated in the main chain were synthesized as a novel polymer ligand for the Ir(I)-catalyzed direct borylation of aromatic compounds. The polyurethanes were insoluble in common organic solvents and soluble in dimethylsulfoxide. The borylation reaction of benzene catalyzed by Ir(I) in the presence of the polymer prepared from 4,4'-bis(hydroxylmethyl)-2,2'-bipyridyl and 1,6-diisocyanatohexane led to the catalytic activities comparable to that in the presence of 2,2'-bipyridyl, while the polymers prepared by the reactions of 4,4'-bis(hydroxylmethyl)-2,2'-bipyridyl with 1,4-diisocyanatobenzene, 1,4-diisocyanato-3-methylbenzene, and bis(4-isocyanatophenyl)methane possesed lower catalytic activities. The high activity observed using the 1,6-diisocyanatohexane-based polyurethane catalyst could have a connection to the fact that this polymer has the highest tendency to form the inter-chain hydrogen bond. The borylation reaction systems with the polymers were biphasic, where the top and bottom layers contained the product and the polymer-based catalysts, respectively. Due to the phase separation, the product isolation and catalyst recycle were readily performed through a simple decantation. The catalyst prepared from 1,6-diisocyanatohexane-based polyurethane was able to be recycled at least five times without a significant decrease in activity. Further, the regio-selectivity in borylation of toluene, anisole, and trifluoromethybenzene was studied using the polyurethane ligands as well as the corresponding small-molecular ligands. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/72196 |
| Appears in Collections: | 触媒科学研究所 (Institute for Catalysis) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 中野 環
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