10.1021/acs.joc.7b00444.s002
Sina P. Zucker
Sina P.
Zucker
Friedrich Wossidlo
Friedrich
Wossidlo
Manuela Weber
Manuela
Weber
Dieter Lentz
Dieter
Lentz
C. Christoph Tzschucke
C. Christoph
Tzschucke
Palladium-Catalyzed
Directed Halogenation of Bipyridine <i>N</i>‑Oxides
American Chemical Society
2017
PCl 3
PBr 3
oxide function
steric hindrance
pyridine-directed functionalization
NBS
latter case
3- bromobipyridine N
bipyridine N
3- chloro
halogenation
NCS
2017-05-24 00:29:31
Dataset
https://acs.figshare.com/articles/dataset/Palladium-Catalyzed_Directed_Halogenation_of_Bipyridine_i_N_i_Oxides/5035223
The
palladium-catalyzed directed C–H halogenation of bipyridine <i>N</i>-oxides was investigated. Using NCS or NBS (<i>N</i>-chloro- or <i>N</i>-bromosuccinimide) and 5 mol % Pd(OAc)<sub>2</sub> in chlorobenzene (0.10 molar) at 110 °C, pyridine-directed
functionalization took place and 3-chloro- or 3-bromobipyridine <i>N</i>-oxides were obtained in high yields. The reaction is sensitive
to steric hindrance by 4- and 6′-substituents. Only in the
latter case, where coordination of palladium by the pyridine is hindered,
3′-halogenation directed by the <i>N</i>-oxide function
was observed. The halogenated products were deoxygenated by PCl<sub>3</sub> or PBr<sub>3</sub>.