Selective synthesis of fused cyclooctatetraenes by [4 + 4] coupling between two different diene units.
In the presence of CuCl and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, the [4 + 4] coupling between zirconacyclopentadienes and 1,3-diiodobutadienes fused through an oxygen or nitrogen five-membered ring proceeded at ambient temperature to afford fully substituted polycyclic cyclo-octatetraenes in good yields. The fused ring moiety of the diiodides plays a critical role. The corresponding acyclic diiodide and a cyclohexane-fused analogue gave no coupling product, and a cyclopentane derivative showed only moderate reactivity. Correlation of the structures of the diiodides and their reactivity was established by an X-ray and density functional study.
Yamamoto
Yoshihiko
Y
Department of Molecular Design and Engineering, Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan. yamamoto@apchem.nagoya-u.ac.jp
Ohno
Tatsuya
T
Itoh
Kenji
K