Facile synthesis of 1,3,4-oxadiazoles via iodine promoted oxidative annulation of methyl-azaheteroarenes and hydrazides

An oxidative sp3 C–H bond of methyl-azaheteroarenes protocol was reported for the synthesis of 1,3,4-oxadiazoles via [4 + 1] annulation with hydrazides. This protocol enables 1,3,4-oxadiazole and quinoline linked diheterocycles via selective oxidation of sp3 C–H bond of methyl-azaheteroarenes in the presence of I2-DMSO. The reaction has a broad substrate scope and good functional group tolerance for methyl-azaheteroarenes and hydrazides.