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Synthesis and stereochemistry of helical polyurethanes based on 2,2 '-dihydroxy-1,1 '-binaphthyl and diisocyanatobenzenes
| Title: | Synthesis and stereochemistry of helical polyurethanes based on 2,2 '-dihydroxy-1,1 '-binaphthyl and diisocyanatobenzenes |
| Authors: | Dai, Heshuang Browse this author | | Shichibu, Yukatsu Browse this author | | Imai, Yoshitane Browse this author | | Hara, Nobuyuki Browse this author | | Konishi, Katsuaki Browse this author | | Wang, Yue Browse this author | | Song, Zhiyi Browse this author →KAKEN DB | | Nakano, Tamaki Browse this author →KAKEN DB |
| Issue Date: | 14-Feb-2020 |
| Publisher: | Royal Society of Chemistry |
| Journal Title: | Polymer chemistry |
| Volume: | 11 |
| Issue: | 6 |
| Start Page: | 1134 |
| End Page: | 1144 |
| Publisher DOI: | 10.1039/c9py01348b |
| Abstract: | Polyaddition between 2,2'-dihydroxy-1,1'-binaphthyl (BINOL) and 1,4-diisocyanatobenzene (14DIB) and that between BINOL and 1,3-diisocyanatobenzene (13DIB) were conducted leading to optically active, helical polyurethanes, poly(BINOL-alt-14DIB) and poly(BINOL-alt-13DIB), respectively. In BINOL-14DIB systems, cyclic dimers were formed along with helical, linear poly(BINOL-alt-14DIB) where the content of dimers was higher at a lower ee of BINOL and the yield of higher-molar-mass, linear polymers was higher at a higher ee of BINOL in feed. (R,R)-, (R,S)-, and (S, S)-Cyclic dimers were completely resolved and separated by chiral HPLC. The (R,S)-cyclic dimer was preferred over (R,R)-and (S, S)-cyclic dimers, while in the reaction using racemic BINOL, the (R,R)-cyclic dimer was preferred over the other isomers at 25-75% ee of (R)-BINOL in feed. Poly(BINOL-alt-14DIB) is proposed to be composed of sequences with rather contiguous (R)-BINOL units as the majority component with rather sporadically incorporated (S)-units as the minor component. Helical sense excess appears to be greater than expected from the ee of BINOL units in the chain, suggesting that (S)-BINOL units sporadically incorporated in a rather contiguous (R)-BINOL unit sequence become a part of the left-handed helical conformation controlled by the chiral influence of contiguous (R)-BINOL units. In addition, the chiral conformation of poly (BINOL-alt-14DIB) and BINOL-14DIB cyclic dimers appeared to be stabilized or enhanced in the solid state. The BINOL-13DIB systems produced linear dimers as major components of the dimer whose content was almost constant regardless of the ee of BINOL in feed. Poly(BINOL-alt-13DIB) is proposed to be composed of sequences with rather randomly distributed (R)- and (S)-BINOL units and may be characterized by sharp, left-handed turns based on BINOL chirality forming a longer-pitched, left-handed helix. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/80428 |
| 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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