I2-promoted one-pot synthesis of 1,3,4-oxadiazoles from aroyl hydrazides and methyl/ethyl acetate

This study aimed to propose an unprecedented I₂-promoted one-pot tandem synthesis of 1,3,4-oxadiazoles through the cyclization between aroyl hydrazides and methyl/ethyl acetate. A diverse array of 2-arylated 1,3,4-oxadiazoles and 5-methyl 1,3,4-oxadiazoles were successfully synthesized in good to excellent yields. The significant advantage of this protocol was its full exploitation of the principle of atomic economy, whereby the reactant served as the reaction solvent directly. Moreover, the reaction demonstrated a broad substrate scope, and the product was readily separable.