Novel synthetic route to octasubstituted naphthalenes from four alkynes and one olefin unit via zirconacyclopentadienes and 1,2-diiodo-3,4,5,6-tetraalkylbenzene.
1,2,3,4-Tetrasubstituted benzene derivatives were prepared by the reaction of zirconacyclopentadienes with vinyl bromide in the presence of NiCl(2)(PPh(3))(2). 1,2-Diiodo-3,4,5,6-tetraalkylbenzenes were formed by treatment of 1,2,3,4-tetraalkylbenzenes with iodine and periodic acid in the presence of a catalytic amount of sulfuric acid. Reaction of the 1,2-diiodo-3,4,5,6-tetraalkylbenzenes with zirconacyclopentadienes in the presence of a stoichiometric amount of CuCl gave sterically crowded octasubstituted naphthalenes in moderate yields.
Zhou
Xin
X
Catalysis Research Center and Graduate School of Pharmaceutical Sciences, Hokkaido University, and SORST, Japan Science and Technology Corporation (JST), Sapporo 001-0021, Japan.
Li
Zhiping
Z
Wang
Hui
H
Kitamura
Masanori
M
Kanno
Ken-Ichiro
K
Nakajima
Kiyohiko
K
Takahashi
Tamotsu
T