HBr + Peroxide: Why Bromine Adds Here #chemistryshorts #mechanism

Hinzugefügt: 2026-05-26

[00:00:00]So, what's going to be the mechanism of this reaction? Well, we start with an alkene and our product is the halide where the halogen is sitting on the less substituted carbon of what used to be a double bond. This reaction is hydrohalogenation because we are reacting it with HBr, which is a hydrogen halide or hydrogen bromide in this particular case, in the presence of the organic peroxide, which means that we are looking at the radical hydrohalogenation reaction. And as any radical reaction, it's going to have three phases: initiation, where we are going to make our radical, in this case that is going to be the Br. Propagation, in which we are going to be making our product, our alkyl halide in this case, and we're going to be recreating the radical that returns back into the cycle. And of course, the termination step, where we are going to see a recombination of any two radicals that we have in our reaction, essentially ending the chain. So, whenever drawing your radical mechanisms, always remember you have to go through the initiation, propagation, and finally end with the termination step.