Organic reactions: Addition
Addition reactions involve two or more reactants combining to form a single product, often seen with alkenes. These reactions create more complex organic molecules, which are essential in the development of pharmaceuticals, plastics and other important materials.
They involve the direct combination of two or more reactants to form a single, more complex product, typically occurring with unsaturated compounds like alkenes. These reactions involve the breaking and forming bonds leading to an increase in the saturation of the molecule.
General reaction of addition reactions
Addition reactions involving hydrogen gas (hydrogenation)
Hydrogenation is an addition reaction where hydrogen gas is added to unsaturated organic compounds, such as alkenes, resulting in the conversion of double or triple bonds into single bonds. This process typically requires a catalyst , such as platinum or nickel.
Addition reactions involving a halogen (halogenation)
Halogenation is an addition reaction where halogens, such as chlorine or bromine, are added to unsaturated organic compounds like alkenes. This reaction results in the formation of dihaloalkanes, and the multiple bonds are converted into single bonds.
Addition reactions involving a hydrogen halide (hydrohalogenation)
Hydrohalogenation is an addition reaction in which a hydrogen halide, such as HCl or HBr, is added to an alkene. This process results in the formation of haloalkanes, where the hydrogen and halogen atoms add across the double bond.
When HBr adds to a double bond, the double bond breaks, and the bromine can end up on either carbon of the broken double bond. This is why two products can be formed in the reaction with HBr.
Addition reactions involving water (hydration)
Hydration is an addition reaction where water is added to an alkene, typically in the presence of an acid catalyst. This reaction converts the unsaturated hydrocarbon into an alcohol.
