Arylation Reactions in the Synthesis of Biologically Important 2,5-Diaryl-1,3,4-Oxadiazoles

Apart from carbon atoms, some cyclic molecules contain other elements and play an extraordinary role in human life. Among these systems, 1,3,4-oxadiazole derivatives deserve special attention due to their biological properties such as antibacterial, antifungal, antitumor, and anti-inflammatory properties. They are commonly used in pharmacology, as well as in fungicidal, herbicidal, and insecticidal agricultural applications. The 1,3,4-oxadiazole fragment is connected directly to other aromatic systems and can be found in the structure of some commercially available drugs, or in potential drug candidates in the final pharmacological testing phase. Therefore, scientists are looking for new hybrid materials based on 1,3,4-oxadiazoles and other biologically active molecules. The most popular methods for constructing new carbon–carbon bonds between two aromatic species include direct arylation, condensation, and cross-coupling reactions. This review article, comprising the literature from 2009 to 2022, discusses a number of arylation reactions in the synthesis of 2,5-diaryl-1,3,4-oxadiazole derivatives.