Intermolecular 1,5-dipolar cycloaddition reaction of tungsten-containing vinylazomethine ylides leading to seven-membered heterocycles.
Intermolecular 1,5-dipolar cycloaddition reaction of tungsten-containing vinylazomethine ylide, generated from o-(alk-3-en-1-ynyl)phenylbenzaldimines and tungsten carbonyl complex, with ketene acetals proceeds efficiently to give azepino[1,2-a]indole derivatives in good yield. Formation of [5+2] or [3+2] cycloadducts can be controlled by an appropriate choice of dipolarophile.
Department of Chemistry, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8551, Japan.
Hiroyuki
H
Kusama
Yasuo
Y
Suzuki
Jun
J
Takaya
Nobuharu
N
Iwasawa