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>.