Lanthanide Trifluoromethanesulfonates - Lewis Acid Catalysis

Lewis Acid Catalysis

Lewis acids are used to catalyse a wide variety of reactions. The mechanism steps are:

1. Lewis acid forms a polar coordinate with a basic site on the reactant (such as an O or N)
2. Its electrons are drawn towards the catalyst, thus activating the reactant
3. The reactant is then able to be transformed by a substitution reaction or addition reaction
4. The product dissociates and catalyst is regenerated

Common Lewis acids include aluminium chloride, ferric chloride and boron trifluoride. These reactions are usually carried out in organic solvents; AlCl₃, for example, reacts violently with water. Typical solvents are dichloromethane and benzene.