Electrophilic addition is a reaction mechanism in which an electrophile interacts with a double bond in an alkene.

Alkenes are unsaturated hydrocarbons characterized by the presence of a carbon-carbon double bond. This double bond represents a region of high electron density, making it attractive to electrophiles—electron-deficient species that seek to acquire electrons. During electrophilic addition reactions, an electrophile adds to the double bond, resulting in the cleavage of the pi bond and the formation of two new sigma bonds.

The mechanism of electrophilic addition consists of three primary steps: (1) the electrophile attacks the pi bond, (2) a carbocation intermediate is formed, and (3) a nucleophile, such as a solvent molecule or a halide ion, performs a nucleophilic attack. The first step is the rate-determining step, meaning it is the slowest phase of the reaction and governs the overall rate.

Electrophilic addition reactions are significant in organic chemistry due to their ability to facilitate the synthesis of a diverse array of compounds. For instance, alkenes can be transformed into alcohols, halides, or other functional groups through these reactions. Additionally, they play a crucial role in the manufacture of plastics, pharmaceuticals, and various industrial chemicals.

In summary, electrophilic addition is a key reaction mechanism that involves the addition of an electrophile to a carbon-carbon double bond in an alkene. This mechanism is vital in organic chemistry because it enables the synthesis of numerous compounds and is integral to the production of many industrial chemicals.