Recent advances in the synthesis of 2,2’-Bipyridines and their derivatives

The sustained interest in the synthesis of new analogs of 2,2’- bipyridines is supported by the importance of compounds featuring bipyridine core in diverse areas of chemical, biomedical and materials research, which relayed into the development of new and expansion of the existing synthetic methods. This short review covers advances in the synthesis of 2,2’- bipyridines, including both synthesis of compounds with a given substitution pattern and development of new methods for assembling the bipyridine core. Special attention is directed to the use of pyridine-N-oxides, as well as metalfree protocols, to facilitate the formation of bipyridines. The review mostly focus on reports published in the last 5-6 years.
1. Introduction
2. Ullmann-type homocoupling reactions
3. Cross-coupling reactions in the synthesis of bipyridines
4. Coupling reactions employing pyridine-N-oxides
5. Other methods for the synthesis of 2,2’-bipyridines
6. Conclusions and further outlook