Iodine-Mediated Domino Oxidative Cyclization: One-Pot Synthesis of 1,3,4-Oxadiazoles via Oxidative Cleavage of C(sp²)–H or C(sp)–H Bond

An I2-promoted, metal-free domino protocol for one-pot synthesis of 1,3,4-oxadiazoles has been developed via oxidative cleavage of C(sp(2))-H or C(sp)-H bonds, followed by cyclization and deacylation. In this reaction, the use of K2CO3 as a base is found to be an essential factor in the cyclization and the C-C bond cleavage. This procedure proceeded smoothly in moderate to high yields with good functional group compatibility.