Abstract Hydrogen peroxide was found to activate iodine in the addition reaction with triple bonds. A facile and technologically straightforward procedure was developed for the synthesis of E??diiodoalkenes based on the reaction of alkynes with an I2–H2O2 system in THF. Selective iodination of terminal and internal alkynes containing electron??donating and electron??withdrawing substituents afforded 16 E??diiodoalkenes in yields up to 89%.
