title: Reductive couplings of 2-halopyridines without external ligand: phosphine-free nickel-catalyzed synthesis of symmetrical and unsymmetrical 2,2'-bipyridines.
abstract: An unexpectedly facile synthetic approach for symmetrical and unsymmetrical 2,2'-bipyridines through the Ni-catalyzed reductive couplings of 2-halopyridines was developed. The couplings were efficiently catalyzed by 5 mol % of NiCl2·6H2O without the use of external ligands. A variety of 2,2'-bipyridines including caerulomycin F have been efficiently synthesized.
authors.affiliation: College of Chemistry, Beijing Normal University , Beijing, 100875 China.
authors.forename: Lian-Yan
authors.initials: LY
authors.lastname: Liao
authors.forename: Xing-Rui
authors.initials: XR
authors.lastname: Kong
authors.forename: Xin-Fang
authors.initials: XF
authors.lastname: Duan