Rapid, Chemoselective and Facile Synthesis of Azines by Hydrazine/I2

We report the reaction of hydrazine hydrate with carbonyl compounds in the presence of molecular iodine at 0–10°C, which affords symmetrical azines in excellent yields in 1 to 4 min without any adverse effect on other substituents. The reactions are rapid and chemoselective, afford excellent yields, and have high‐purity products. The workup procedure is environmentally benign and does not require solvent extraction.