CuCl2 induced reactions of 6-ethynyl- and 6-cyano-5-aryl-2,2′-bipyridines with various N- and O-nucleophiles in comparison with the reactions of relative 1,2,4-triazines

Meanwhile 5-aryl-6-cyano-2,2′-bipyridines are very stable towards various nucleophiles, addition copper(II) chloride to the reactional mixture facilitates nucleophilic addition to the cyano group dramatically. The cyanobipyridines react easily with water, methanol, ethanolamine in the presence of CuCl2 yielding well-crystallized complexes containing carboxylates, carboximidates or carboxamidines as ligands. 5-Cyano-1,2,4-triazines are more active in the reactions due to higher electron-withdrawing properties of this heterocycle. Due to the same reason acetylene moiety of 5-ethynyl-3-pyridyl-1,2,4-triazine adds water quite easily but in the presence of copper chloride as well.

Graphical abstractStable towards nucleophilic attack 5-aryl-6-cyano-2,2′-bipyridines react easily with water, methanol, ethanolamine in the presence of copper(II) chloride yielding complexes containing carboxylates, carboximidates or carboxamidines. Relative 5-cyano- as well 5-ethynyl-3-pyridyl-1,2,4-triazines are more active in the CuCl2 induced reactions due to higher electron-withdrawing properties of this heterocycle.Figure optionsDownload full-size imageDownload as PowerPoint slide