Radical Hydrohalogenation

When peroxides are present, Hydrobromic Acid (HBr) interacts with a specific alkene in a manner that is consistent with anti-Markovnikov addition. The regiochemistry of this reaction is dictated by the mechanism, which involves the halogen targeting the least obstructed carbon in the unsaturated compound. This chain reaction mechanism bears a resemblance to free radical halogenation, where the peroxide facilitates the creation of a bromine radical. However, this particular process is exclusive to the addition of HBr. Among other hydrogen halides such as Hydrofluoric Acid (HF), Hydrochloric Acid (HCl), and Hydroiodic Acid (HI), only HCl exhibits a similar reaction, but the rate of this reaction is too sluggish for practical application in synthesis.