Intramolecular cyclization of beta,beta-difluorostyrenes bearing an iminomethyl or a diazenyl group at the ortho position: synthesis of 3-fluorinated isoquinoline and cinnoline derivatives.
o-Formyl-substituted beta,beta-difluorostyrenes readily react with NH(2)OH.HCl or NH(4)OAc to afford 3-fluoroisoquinoline derivatives in good yield via (i) the formation of the corresponding oximes or imines and (ii) subsequent intramolecular replacement of a vinylic fluorine by the sp(2) nitrogen of the iminomethyl group (HON=CH- or HN=CH-). Beta,beta-Difluorostyrenes bearing an o-diazenyl group (HN=N-), generated by reduction of the corresponding diazonium ions, undergo a similar substitution to afford 3-fluorinated cinnolines.
Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan. junji@chem.tsukuba.ac.jp
Junji
J
Ichikawa
Yukinori
Y
Wada
Hiroyuki
H
Kuroki
Jun
J
Mihara
Ryo
R
Nadano
D001391:Azo Compounds / Q000737:chemistry; D003500:Cyclization; D006574:Heterocyclic Compounds, 2-Ring / Q000138:chemical synthesis* / Q000737:chemistry; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis* / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D007546:Isoquinolines / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013343:Styrenes / Q000737:chemistry*
D001391:Azo Compounds; D006574:Heterocyclic Compounds, 2-Ring; D006845:Hydrocarbons, Fluorinated; D007097:Imines; D007546:Isoquinolines; D013343:Styrenes; C039109:isoquinoline; C476282:cinnoline