Tetrazoles

In this chapter, the tetrazoles investigations between 2009 and 2019 are summarized. Emphasis is made on the publications reported in 2017–18. The attention is focused on the most important events of tetrazole chemistry such as use of new catalysts, promoters and other experimental conditions favoring processes allowing the formation and functionalization of tetrazole ring. The focus is placed on the development of safe and eco-friendly methods to access tetrazoles. A special section of the review is devoted to the coordination chemistry of tetrazole, which is developing recently. The most important achievements reporting the use of tetrazoles as energetic materials and in medicinal chemistry are highlighted. Strategic directions that predict the tetrazole chemistry for the next decade have been underlined.