Abstract
Asymmetric hydroboration of cis- and trans-1,4-polyisoprene was carried out using optically active triisopinocampheyldiborane and optically active polymers were obtained. In the case of the hydroboration of cis-1,4-polyisoprene, the use of dextrorotatory α-pinene ([α]D +14.9°), yielded the laevorotatory polymer ([α]D −2.3°) having a 98 per cent hydroxyl group content. On the contrary, the use of laevorotatory α-pinene ([α]D −26.6° and −28.6°) yielded the dextrorotatory polymers ([α]D +2.4∼3.6°) having a 85–100 per cent hydroxyl group content. The absolute values of [α]D for the polymers were increased with the increase in hydroxyl group content and the absolute value of [α]D of α-pinene used. The optically rotatory dispersion curves were found to fit the simple Drude equation and the λc value of the polymers was about 164 mμ. The λc value suggested that the chromophore which caused optical activity was −OH group. The hydroboration of trans-1,4-polyisoprene was also carried out and optically active polymers ([α]D +0.6–1.2°) having a 90–100 percent hydroxyl group content were obtained using α-pinene ([α]D −28.6°). Furthermore, the asymmetric hydroboration of cis-polybutadiene, butadiene–styrene and random butadiene–acrylonitrile copolymers was carried out, but these hydroxylated polymers had no optical activity. The hydro-xylated butadiene–acrylonitrile alternating copolymer showed optical activity.
Similar content being viewed by others
Article PDF
References
H. C. Brown and G. Zweifel, J. Am. Chem. Soc., 83, 486 (1961).
H. C. Brown, N. R. Ayyanger, and G. Zweifel, J. Am. Chem. Soc., 86, 397 (1964).
H. Ikeda, A. Kogure, K. Shiina, and Y. Minoura, Kogyo Kagaku Zasshi (J. Chem. Soc., Japan, Chem. Ind. Sect.) 68, 1103 (1965).
I. Heilbron et al., “Dictionary of Organic Compounds,” Eyre and Spottiswoode Ltd., London, 1965, p. 2756.
J. Furukawa, Y. Iseda, K. Haga, and N. Kataoka, J. Polym. Sci., Part B, 7, 47 (1969).
H. C. Brown, G. Zweifel, and K. Nagase, J. Am. Chem. Soc., 84, 183 (1962).
H. C. Brown, N. R. Ayyanger, and G. Zweifel, J. Am. Chem. Soc., 86, 1071 (1964).
F. J. Welch, J. Polym. Sci., 61, 243 (1962).
R. L. Hansen and R. R. Haman, J. Phys. Chem., 67, 2868 (1963).
P. G. Allies and P. B. Brindley, J. Chem. Soc., B, 1126 (1969).
H. C. Brown, N. R. Ayyanger, and G. Zweifel, J. Am. Chem. Soc., 84, 4341 (1962).
H. C. Brown, N. R. Ayyanger, and G. Zweifel, J. Am. Chem. Soc., 84, 4342 (1962).
H. L. Frish, C. Schuerch, and M. Szwarc, J. Polym. Sci., 11, 559 (1953).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Yamaguchi, H., Azuma, K. & Minoura, Y. Asymmetric Hydroboration of Diene Polymers. Polym J 3, 12–20 (1972). https://doi.org/10.1295/polymj.3.12
Issue Date:
DOI: https://doi.org/10.1295/polymj.3.12