Palladium catalyzed direct C-H arylation of 1,3,4-oxadiazole using ligand combination approach

The use of combination of readily available ligands in palladium catalyzed C-H arylation of 1,3,4-oxadiazole with iodoarenes as well as bromoarenes is reported. The combination of phenanthroline monohydrate (Phen. H2O) and triphenyl phosphine (PPh3) with Pd catalyst exhibited improved catalytical activity compared to a single ligand used separately in the reaction. A wide range of 2,5-diarylated-1,3,4-oxadiazoles with a variation of aryl component at C-5 position is synthesized using this method. Overall, this method exhibits a broad substrate scope and high functional group tolerance. In addition, this method is used for the synthesis of carbazole/oxadiazole and biphenyl/oxadiazole based hybrid compounds which are known for their interesting photophysical properties.