Friedel-Crafts-type cyclization of 2,2-difluorovinyl ketones via alpha-fluorocarbocations and its application in domino cyclizations.
[Structure: see text] 2,2-Difluorovinyl ketones bearing an aryl group undergo Friedel-Crafts-type cyclization via carbocations stabilized by alpha-fluorines on treatment with a trimethylsilylating agent [Me3SiOTf or Me3SiB(OTf)4]. The reaction affords 4-fluorinated 3-acyl-1,2-dihydronaphthalenes, which are successfully subjected to a substitution-cyclodehydration process or a Nazarov-type cyclization to construct fused polycyclic systems.
Ichikawa
Junji
J
Department of Chemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. junji@chem.s.u-tokyo.ac.jp
Kaneko
Mikio
M
Yokota
Misaki
M
Itonaga
Masaaki
M
Yokoyama
Takaharu
T