H. Yasuda, Y. Ohnuma, A. Nakamura
Apr 1, 1980
Citations
0
Influential Citations
48
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
A series of bis(dienyl)beryllium and bis(dienyl)zinc compounds were prepared by metal exchange reaction from seven different dienyl anions and were isolated as crystals of TMEDA complexes. Bis(dienyl)beryllium compounds of open chain structure obtained from pentadienyl, 2-methylpentadienyl, and 3-methylpentadienyl anions assume the terminally σ-bonded (E)-2,4-pentadienyl structure in solution as evidenced by 1H-NMR and 13C-NMR spectroscopies. Hydrolysis of these compounds gave 1,4-dienes regioselectively. The corresponding bis(dienyl)zinc compounds exist as a (Z), (E) mixture of teminally σ-bonded structures. An X-ray analysis of pentadienylzinc chloride·TMEDA complex showed that it had terminally σ-bonded (E)-2,4-pentadienyl structure with s-trans conformation. Steric effect of two methyl substituents in bis(2,4-dimethylpentadienyl)zinc induces the (Z) configuration which leads to the fluxional behavior by rapid 1,5-rearrangement above −80 °C.