Isodiiodomethane is the methylene transfer agent in cyclopropanation reactions with olefins using ultraviolent photolysis of diiodomethane in solutions: A density functional theory investigation of the reactions of isodiiodomethane, iodomethyl radical, and iodomethyl cation with ethylene

Abstract

We examine the chemical reactions of the isodiiodometharie (CH 2I-I), ·CH 2I and CH 2I + species with ethylene using density functional theory computations. The CH 2I-I species readily reacts with ethylene to give the cyclopropane product and an I 2 product via a one-step reaction with a barrier height of ∼2.9 kcal/mol. However, the ·CH 2I and CH 2I + species have much more difficult pathways (with larger potential barriers) to react with ethylene via a two-step reaction mechanism. Comparison of experimental results to our present calculations results indicates that the CH 2I-I photoproduct species is most likely the methylene transfer agent for the cyclopropanation reaction of olefins via ultravilet photoexcitation of diiodomethane.