1,2,4-Oxadiazoles

The 1,2,4-oxadiazole is a five-membered heterocycle that presents many useful properties. The presence of a labile ON bond and its low aromaticity are some of the key features of its multifaceted reactivity, characterized by a high tendency to rearrange. Many applications in the fields of material and biological sciences continue to provide a significant impetus for the development of effective synthetic methods. All of these features will be reviewed in this chapter with particular emphasis to research reported since 2008.