Synthesis of 2,2'-bipyridines : from versatile building blocks to sexy architectures and functional (nano)materials

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.