138006-41-4Relevant articles and documents
Chiral Hexahalogenated 4,4′-Bipyridines
Mamane,Peluso,Aubert,Cossu,Pale
, p. 4576 - 4587 (2016/07/06)
The preparation of 27 isomers of chiral hexahalogeno-4,4′-bipyridines by means of two complementary methods is described. The first one is convergent and based on the LDA-induced 4,4′-dimerization of trihalopyridines, whereas the second method is divergent and achieved through regioselective halogenation reactions of 4,4′-bipyridine-2,2′-diones. Iodine in 2,2′-positions of the 4,4′-bipyridines was introduced by a copper-catalyzed Finkelstein reaction (Buchwald procedure) performed on 2,2′-dibromo derivatives. Selected compounds of this new family of atropisomeric 4,4′-bipyridines were enantioseparated by high performance liquid chromatography on chiral stationary phases, and the absolute configurations of the separated enantiomers were assigned by using X-ray diffraction analysis. The latter revealed that various halogen bond types are responsible for crystal cohesion.
Highly Regioselective Halogenation of Pyridine N -Oxide: Practical Access to 2-Halo-Substituted Pyridines
Chen, Ying,Huang, Jinkun,Hwang, Tsang-Lin,Chen, Maosheng J.,Tedrow, Jason S.,Farrell, Robert P.,Bio, Matthew M.,Cui, Sheng
supporting information, p. 2948 - 2951 (2015/06/30)
A highly efficient and regioselective halogenation reaction of unsymmetrical pyridine N-oxide under mild conditions is described. The methodology provides a practical access to various 2-halo-substituted pyridines, which are pharmaceutically important intermediates.
