Metal-catalyzed [6 + 3] cycloaddition of tropone with azomethine ylides: a practical access to piperidine-fused bicyclic heterocycles.
The first metal-catalyzed [6 + 3] cycloaddition of tropone with azomethine ylides has been developed. With the use of a chiral ferrocenylphosphine-copper(I) complex as the catalyst, the asymmetric variant of the [6 + 3] cycloaddition has also been successfully achieved. The reactions proceeded smoothly under mild conditions, affording piperidine-fused bicyclic heterocycles in moderate to high yields with good to excellent diastereo- and enantioselectivies. The procedures are operationally simple and the catalysts are cheap and readily accessible, thus providing a practical approach to piperidine-fused bicyclic heterocycles.
Department of Applied Chemistry, China Agricultural University , Beijing 100193, China.
Honglei
H
Liu
Yang
Y
Wu
Yan
Y
Zhao
Zhen
Z
Li
Lei
L
Zhang
Wenjun
W
Yang
Hui
H
Jiang
Chengfeng
C
Jing
Hao
H
Yu
Bo
B
Wang
Yumei
Y
Xiao
Hongchao
H
Guo