The latest synthetic strategies to prepare 2,2-bipyridine and its mono-substituted, symmetrical and unsymmetrical 3,3-, 4,4-, 5,5-, and 6,6-disubstituted derivatives are critically discussed and evaluated. Different coupling procedures to achieve new symmetrical and unsymmetrical functionalized 2,2-bipyridines, such as Stille-type, Negishi-type, and Suzuki-type cross-coupling reactions are discussed in detail. Moreover, condensation procedures that allow further variations are presented. The application of functional group transformations for access to additional groups is examined.
Newkome, G. R., Patri, A. K., Holder, E., & Schubert, U. S. (2004). Synthesis of 2,2'-bipyridines : from versatile building blocks to sexy architectures and functional (nano)materials. European Journal of Organic Chemistry, 2004(2), 235-254. https://doi.org/10.1002/ejoc.200300399