Main Article Content
Abstract
2-([E]-1-Alkenyl)-1,3,2-dioxaborinanes prepared from the hydroboration of terminal alkynes with dibromoborane-methyl sulfide complex followed by treatment with 1,3-propane diol readily react with copper(I) bromide-methyl sulfide in the presence of a hindered base such as potassium-t-butoxide at 0 °C to afford (E,E)-symmetrical conjugated dienes. The dienes are formed with retention of configuration in a highly stereospecific manner predetermined from the alkenylboronate esters stereochemistry. Since the hydroboration of alkynes with dialkylboranes proceeds in a highly regio- and stereospecific manner under mild conditions, this then provides a direct route from acetylenes to the corresponding [E,E]-conjugated dienes. The recent accessibility of 2-([Z]-1-alkenyl)-1,3,2-dioxaborinanes also allows preparation of stereochemically pure [Z,Z]-conjugated dienes. The reaction is shown to probably proceed through an alkenylcopper (I) intermediate, which undergoes thermal dimerization to yield the corresponding stereodefined symmetrical dienes. The present procedures allow the preparation of either (E,E)- or (Z,Z)-symmetrical conjugated dienes in good yields and in high stereo-chemical purities (> 98 %).
Keywords
Article Details
References
- (a) G. Zweifel and R.L. Miller, J. Am. Chem. Soc., 92, 6678 (1970); https://doi.org/10.1021/ja00725a070. (b) G. Wilke and H. Muller, Justus Liebigs Ann. Chem., 629, 222 (1960); https://doi.org/10.1002/jlac.19606290117. (c) G. Zweifel and W.L. Polston, J. Am. Chem. Soc., 92, 4068 (1970); https://doi.org/10.1021/ja00716a040. (d) E. Negishi and T. Yoshida, J. Chem. Soc. Chem. Commun., 606 (1973); https://doi.org/10.1039/c39730000606. (e) E. Negishi, G. Lew and T. Yoshida, J. Chem. Soc. Chem. Commun., 874 (1973); https://doi.org/10.1039/c39730000874. (f) H.C. Brown and N. Ravindran, J. Org. Chem., 38, 1617 (1973); https://doi.org/10.1021/jo00948a041. (g) G. Zweifel, W.L. Polston and C.C. Whitney, J. Am. Chem. Soc., 90, 6243 (1968); https://doi.org/10.1021/ja01024a068. (h) Y. Yamamoto, H. Yatagai, K. Maruyama, A. Sonoda and S. Murahashi, J. Am. Chem. Soc., 99, 5652 (1977); https://doi.org/10.1021/ja00459a021. (i) M. Yoshifuji, M.J. Loots and J. Schwartz, Tetrahedron Lett., 18, 1303 (1977); https://doi.org/10.1016/S0040-4039(01)93002-3. (j) E. Negishi, T. Takahashi, S. Baba, D.E. Van Horn and N. Okukado, J. Am. Chem. Soc., 109, 2393 (1987); https://doi.org/10.1021/ja00242a024. (k) E. Negishi, T. Yoshida, A. Abramovitch, G. Lew and R.M. Williams, Tetrahedron, 47, 343 (1991); https://doi.org/10.1016/S0040-4020(01)90494-6.
- H.C. Brown and N. Ravindran, J. Am. Chem. Soc., 98, 1785 (1976); https://doi.org/10.1021/ja00423a025.
- H.C. Brown and G.A. Molander, J. Org. Chem., 46, 645 (1981); https://doi.org/10.1021/jo00316a037.
- H.C. Brown, N.G. Bhat and V. Somayaji, Organometallics, 2, 1311 (1983); https://doi.org/10.1021/om50004a008.
- H.C. Brown and T. Imai, Organometallics, 3, 1392 (1984); https://doi.org/10.1021/om00087a013.
References
(a) G. Zweifel and R.L. Miller, J. Am. Chem. Soc., 92, 6678 (1970); https://doi.org/10.1021/ja00725a070. (b) G. Wilke and H. Muller, Justus Liebigs Ann. Chem., 629, 222 (1960); https://doi.org/10.1002/jlac.19606290117. (c) G. Zweifel and W.L. Polston, J. Am. Chem. Soc., 92, 4068 (1970); https://doi.org/10.1021/ja00716a040. (d) E. Negishi and T. Yoshida, J. Chem. Soc. Chem. Commun., 606 (1973); https://doi.org/10.1039/c39730000606. (e) E. Negishi, G. Lew and T. Yoshida, J. Chem. Soc. Chem. Commun., 874 (1973); https://doi.org/10.1039/c39730000874. (f) H.C. Brown and N. Ravindran, J. Org. Chem., 38, 1617 (1973); https://doi.org/10.1021/jo00948a041. (g) G. Zweifel, W.L. Polston and C.C. Whitney, J. Am. Chem. Soc., 90, 6243 (1968); https://doi.org/10.1021/ja01024a068. (h) Y. Yamamoto, H. Yatagai, K. Maruyama, A. Sonoda and S. Murahashi, J. Am. Chem. Soc., 99, 5652 (1977); https://doi.org/10.1021/ja00459a021. (i) M. Yoshifuji, M.J. Loots and J. Schwartz, Tetrahedron Lett., 18, 1303 (1977); https://doi.org/10.1016/S0040-4039(01)93002-3. (j) E. Negishi, T. Takahashi, S. Baba, D.E. Van Horn and N. Okukado, J. Am. Chem. Soc., 109, 2393 (1987); https://doi.org/10.1021/ja00242a024. (k) E. Negishi, T. Yoshida, A. Abramovitch, G. Lew and R.M. Williams, Tetrahedron, 47, 343 (1991); https://doi.org/10.1016/S0040-4020(01)90494-6.
H.C. Brown and N. Ravindran, J. Am. Chem. Soc., 98, 1785 (1976); https://doi.org/10.1021/ja00423a025.
H.C. Brown and G.A. Molander, J. Org. Chem., 46, 645 (1981); https://doi.org/10.1021/jo00316a037.
H.C. Brown, N.G. Bhat and V. Somayaji, Organometallics, 2, 1311 (1983); https://doi.org/10.1021/om50004a008.
H.C. Brown and T. Imai, Organometallics, 3, 1392 (1984); https://doi.org/10.1021/om00087a013.